Características clínicas, métodos diagnósticos y evolución de la criptococosis extrameníngea en personas viviendo con VIH / Clinical features, diagnosis methods and evolution in non meningeal cryptococcosis in people living with VIH

La criptococosis es una micosis grave que se manifiesta, en el 90% de los casos, como una meningoencefalitis, especialmente en las personas con VIH. El objetivo de este estudio es describir los casos de criptococosis extrameníngea en personas viviendo con VIH y conocer cuántas de estas padecen compromiso meníngeo concomitante. Además, determinar la relación con el título de antígeno polisacárido capsular de Cryptococcus en suero. Se realizó un estudio retrospectivo, observacional y analítico. Se incluyeron personas viviendo con VIH cuyo diagnóstico inicial de criptococosis se había realizado a partir de muestras extrameníngeas en el período comprendido entre 2012 y 2019. Los pacientes se dividieron en dos grupos. Grupo 1, pacientes sin compromiso meníngeo; Grupo 2, aquellos que finalmente tenían compromiso del SNC. De un total de 531 criptococosis registradas en ese período, se incluyeron 113 pacientes (21%), de los cuales en 58 se comprobó el compromiso meníngeo. No se observaron diferencias significativas en cuanto a la mortalidad entre ambos grupos.Ninguno de los pacientes con antigenemia por LFA (antígeno capsular en suero por inmunocromatografía) positiva, pero con antigenemia por aglutinación de partículas de látex (AL) negativa, tuvo compromiso meníngeo. Se observó que títulos de antígeno para Cryptococcus en suero por AL mayor o igual a 1/100 se correlacionaron con un aumento de 30 veces en la posibilidad de padecer meningitis. En todos los casos se debe descartar el compromiso del SNC. La AL sigue siendo una prueba útil y complementaria, debido a que en los casos con AL negativa no se observó compromiso meníngeo

Cryptococcosis is a serious mycosis that manifests itself, in 90% of cases, as meningoencephalitis, especially in AIDS patients. The objective of this study is to describe the extra-meningeal cases of cryptococcosis in people living with HIV and to know how many of them suffer from concomitant meningeal involvement. Also, to determine its relationship with the Cryptococcus capsular polysaccharide antigen titer in serum.A retrospective, observational and analytical study was carried out. HIV-positive patients whose initial diagnosis had been made from extrameningeal samples in the period between 2012 and 2019 were included. The patients were divided into 2 groups. Group 1: patients without meningeal involvement; group 2: those who finally had CNS involvement.Of a total of 531 cryptococcosis registered in this period, 113 patients (21%) were included, of whom meningeal involvement was confirmed in 58. No significant differences were observed in terms of mortality in both groups.None of the patients with positive LFA antigenemia (Capsular antigen detection by lateral Flow assay) but negative latex particle agglutination (LA) antigenemia had meningeal involvement. LFA was found to be highly sensitive and allows early diagnosis, but it does not replace other diagnostic procedures.Serum Cryptococcus antigen titers for by LA greater than or equal to 1/100 were found to correlate with a 30-fold increase in the likelihood of meningitis.In all cases, CNS involvement must be ruled out. LA continues to be a useful and complementary test, because in cases with negative LA, no meningeal involvement was observed

Antigenemia temprana de Cryptococcus en pacientes asintomáticos VIH positivos en Barranquilla, Colombia / Cryptococcus early antigenemia in HIV positive asymptomatic patients in Barranquilla, Colombia

Resumen La criptococosis meníngea presenta alta mortalidad mundial, especialmente en población VIH/sida. La OMS recomienda detectar el antígeno capsular de Crypto coccus como estrategia para un diagnóstico temprano y poder minimizar complicaciones. Objetivo: realizar antigenemia temprana de Cryptococcus mediante in munocromatografía/ensayo de flujo lateral en pacientes asintomáticos VIH+. Material y método: estudio descriptivo observacional; entre julio-2016 y mayo-2019 se procesaron mediante ensayo de flujo lateral, muestras de suero de 169 pacientes asintomáticos VIH+, con CD4 ≤120 cel/μL en Barranquilla, Colombia. Ante resultado positivo, se indicó profilaxis con fluconazol; se hizo seguimiento a todos los casos. Resultados: la antigenemia fue positiva en cinco pacientes (2,96%); uno falleció, cuatro recibieron profilaxis y la prueba se negativizó en dos. Los pacientes con resultado negativo inicial no desarrollaron durante el estudio sinto matología compatible con esta micosis. Discusión: el ensayo de flujo lateral de Cryptococcus está recomendado para el diagnóstico temprano de la criptococosis en población VIH/sida. Conclusión: detectar tempranamente el antígeno circulante de Cryptococcus mediante ensayo de flujo lateral en pacientes asintomáticos VIH+, permitió instaurar profilaxis oportuna, hacer seguimiento y control para reducir la mortalidad asociada con la criptococosis meníngea.

Abstract Meningeal cryptococcosis presents high levels of global mortality, especially in the HIV/AIDS population. The WHO recommends detecting the capsular antigen as an important strategy for early diagnosis and be able to minimize complications. Objective: Perform early cryptococcal antigenemia by immunochromatographic/ lateral flow assay in asymptomatic HIV+ patients. Material and method: descriptive observational study; between July-2016 and May-2019, serum samples from 169 asymptomatic HIV+ patients with CD4 ≤120 cells/μL were processed by lateral flow assay in Barranquilla, Colombia. Given a positive result, prophylaxis with fluconazole was indicated; all cases were followed up. Results: antigenemia was positive in five (2.96%) patients; one died; four received prophylaxis, and the test turned negative in two. The patients with an initial negative result, did not developed symptoms compatible with this mycosis during the study period. Discussion: lateral flow assay for Cryptococcus is recommended for the early diagnosis of cryptococcosis in the HIV/AIDS population. Conclusion: early detection of circulating Cryptococcus antigen by lateral flow assay in HIV+ patients allowed the establishment of timely prophylaxis, follow-up, and control to reduce mortality associated with meningeal cryptococcosis.

Cryptococcal Antigenemia in HIV-Infected Patients with CD4+ T-cell Count ≤ 200 cells/μl: A study from a tertiary care hospital

Introduction: Cryptococcal meningitis is one of the leadingopportunistic infections associated with high mortality. Thepresent study was carried out to determine the prevalence ofcryptococcal antigenemia in HIV-infected patients with CD4+T-cell count ≤ 200 cells/μl.Material and methods: A cross-sectional study includinga total of 100 blood samples of HIV-infected patients withCD4+ T-cell count ≤ 200 cells/μl was carried out in a tertiarycare hospital. The Cryptococcal Antigen Latex AgglutinationTest was performed on serum separated from blood samplesincluded in the study group. A positive cryptococcalantigenemia was diagnosed by positive latex agglutinationtest of cryptococcal polysaccharide antigen in serum. BMI ofall patients included in the study group was calculated andWHO clinical staging of all patients was noted.Results: Three cases out of 100 were positive for cryptococcalantigenemia. The positive cases showed correlation with lowBMI and WHO Clinical stage II and III of HIV disease. Inthe present study, 33.33% and 66.67% of positive cases hadCD4+ T-cell count within the range of 0-100cells/μl and101-200cells/μl respectively.Conclusion: It is important to implement routine screeningfor cryptococcal antigen among HIV-infected cases withCD4+ T-cell count ≤ 200 cells/μl for early detection ofcryptococcal antigenemia. It will help in identifying the riskof subsequent cryptococcal meningitis and initiation of preemptive antifungal treatment.

Standardization of antigenemia and qpcr cut-off values in whole blood for the detection of cytomegalovirus disease in hiv patients

Abstract INTRODUCTION: We defined the cut-off values of the antigenemia and cytomegalovirus (CMV) DNA tests in HIV/AIDS patients to identify CMV disease. METHODS: A total of 97 samples from 68 patients with and without CMV disease were analyzed by viral DNA detection and antigenemia assay. RESULTS: Qualitative and quantitative results significantly differed between assays. The cut-off values for the antigenemia and qPCR assays were 1.5 positive cells/200,000 leukocytes and 3.715 log/mL, respectively. CONCLUSIONS: Antigenemia and qPCR are suitable for monitoring CMV disease in HIV patients, however, the threshold values should be determined within the centers where the patients are monitored.

Incidence of Cytomegalovirus Antigenemia in patients with autoimmune rheumatic diseases: a 3-year retrospective study

Abstract Objective: To determine the incidence of positive CMV antigenemia (CMV-Ag) in patients with autoimmune rheumatic diseases (AIRD) and to describe the outcomes of these patients. Methods: From January 2011 to December 2014, a total of 443 patients with AIRD were enrolled in this retrospective analysis. Demographic, clinical and laboratory data, current clinical manifestations, organs affected by CMV infection, therapeutic management and outcomes were evaluated. The CMV-Ag was considered positive when one cell was detected at least. Results: CMV-Ag was requested in 70 (15.8%) patients with suspicious CMV infection and was positive in 24 (34.3%). The incidence rate of positive CMV-Ag was 4.97% (95% CI 3.1-7.4%). Systemic lupus erythematosus (SLE) (59%), followed by ANCA-related vasculitis (18.2%) and rheumatoid arthritis (9%) were the diseases more associated with positive CMV-Ag. At the time of CMV infection, SLE patients had moderate to severe disease activity, with high frequency of positive anti-dsDNA antibody (69.2%) and complement consumption (61.5%), as well as high doses of corticosteroids and use of immunosuppressants. The main CMV sites involved were lung (45.5%), bone marrow (40. 9%) and gut (27.3%). Mortality rate was 45.5%, especially in those with higher doses of daily oral corticosteroids (107 ±55.4 mg vs. 71.7 ±46.3 mg; p = 0.07) and lower number of lymphocytes (309 ± 368.2/mm3 vs. 821 ± 692.9/ mm3; p = 0.06). Conclusions: Our data showed high incidence of CMV-Ag in AIRD patients, particularly those with SLE and greater disease severity. In addition, it was observed high mortality in these patients, highlighting the CMV infection should be included in differential diagnosis.

Screening for cryptococcal antigenemia and analyzsis of the related cryptococcal lesions in hospitalized human immunodeficiency virus infected patients / 中华传染病杂志

Objective To evaluate the prevalence of cryptococcal antigenemia and explore the related cryptococcal lesions in hospitalized human immunodeficiency virus ( HIV )-infected patients . Methods Medical records of 517 HIV-infected patients ,including patients'age ,sex ,clinical features , previous medical history ,laboratory tests ,chest CT ,treatment and the response to treatment ,in the Second Hospital of the Nanjing between January 2016 and February 2018 were retrospectively analyzed . The serum cryptococcal antigen (sCrAg) was detected by lateral flow immunoassay .The χ2 test or Fisherexact test was used to perform the statistical analysis .Results Among 517 HIV-infected cases ,51 were sCrAg positive ,of whom 96 .1％ (49 cases) were men .The cases with CD4+ T lymphocyte count <100 × 106 cells/L accounted for 66 .2％ (342 cases) ,while 90 .2％ (46 cases) in sCrAg-positive patients showed CD4+ T lymphocyte count < 100 × 106 cells/L with statistical significance (χ2 = 14 .6 , P< 0 .01 ) . Multivariable analysis revealed that CD4+ T lymphocyte count <100 × 106 cells/L was independent risk factor for cryptococcal antigenemia (OR= 4 .7;95％ CI:1 .8 -12 .5 , P< 0 .01) .Clinical cryptococcal diseases were found in 76 .4％ (39/51 ) of patients with cryptococcal antigenemia , and cryptococcal meningitis (CM) ,pulmonary cyptococcosis (PC) and cryptococcal septicemia were found in 56％ (28/50) ,52 .9％ (27/51) and 44 .4％ (16/36) of the patients ,respectively .Cryptoccal disease was not identified in 21 .6％ (11/51 ) of the patients with cryptococcal antigenemia (isolated cryptococcal antigenemia) .The median (range) sCrAg titers of the patients with and without CM were 1:1280 (1:10-1:2560) and 1 :15 (1:2-1:2560) ,respectively (P<0 .01) .The proportion of CM in patients with sCrAg titers ≤1:5 ,1:10 -1:320 and ≥1:640 were 0 (0/10) ,50％ (10/20) and 90％ (18/20) , respectively .When cryptococcal infection was restricted to the lung ,87 .5％ (7/8) of the patients had sCrAg titers ≤1:20 .30％ (3/10) of the patients with sCrAg titers ≤1:5 had PC .The median (range) sCrAg titers of the patients with cryptococcal septicemia and with isolated cryptococcal antigenemia were 1:1280 (1:10 -1:2560 ) and 1:5 (1:2 -1:320 ) , respectively . Conclusions T he prevalence of cryptococcal antigenmia is high in hospitalized HIV-infected patients . Most patients with cryptococcal antigenemia have developed cryptococcal diseases .The sCrAg titer in HIV patients may ,in some extend , predicts the condition of cryptococcal infection .sCrAg titers ≥ 1:640 are strongly suggestive of CM . Patients with sCrAg titers ≤1:5 seems unlikely to have CM or cryptococcal septicemia ,however ,clinician should still be alarmed of possible PC .

Clinical correlates of pp65 antigenemia monitoring in the first months of post kidney transplant in patients undergoing universal prophylaxis or preemptive therapy

Abstract Introduction: Human cytomegalovirus is a major cause of morbidity in kidney transplant patients. Objectives: We aimed to study viral replication and serological response in the first months post kidney transplant in patients undergoing universal prophylaxis or preemptive therapy and correlate the findings with the clinical course of Human cytomegalovirus infection. Patients and methods: Independent from the clinical strategy adopted for managing Human cytomegalovirus infection, prophylaxis versus preemptive therapy, the pp65 antigenemia assay and serological response were assessed on the day of transplantation, and then weekly during the first three months of post-transplant. Results: From the 32 transplant recipients, 16 were positive for pp65 antigenemia, with a similar incidence rate in each group. There were no positive results in the first three weeks of monitoring; the positivity rate peaked at week eight. There was a trend for a higher and earlier frequency of positivity in the universal prophylaxis group in which the course of the Human cytomegalovirus infection was also more severe. Despite the differences in clinical picture and in the initial immunosuppressant schedule, the serological response was similar in both groups. Conclusion: Routine monitoring during the first three post-transplant months has a positive impact on the early detection of Human cytomegalovirus viral replication allowing for timely treatment in order to reduce morbidity of the disease. The strategy of universal therapy employing intravenous ganciclovir was associated to a worse clinical course of the Human cytomegalovirus infection suggesting that the use of >10 cells/2 × 105 leukocytes as a cut-off in this setting may be inappropriate.

pp65 antigen and human cytomegalovirus infection / 国际儿科学杂志

HCMV infection can cause hepatopathy,pneumonia,diarrhea,thrombocytopenic purpura,and sensorineural hearing loss(SNHL),with high morbility and mortality.pp65(phosphoprotein 65),a major constitutive protein of virion,is closely associated with viral gene expression,immune evasion and cell metabolism.pp65 antigenemia level has positive correlation with clinical symptom,which can guide the preemptive therapyand improve prognosis,is considered as one of the golden standard methods of active cytomegalovirus infection.In this paper,the pp65 protein properties,pathogenesis,application in diagnosis and prevention are reviewed.

Antigenemia y reacción de polimerasa en cadena en tiempo real en el diagnóstico de enfermedad por citomegalovirus en adultos con virus de inmunodeficiencia adquirida / Antigenemia and real time polymerase chain reaction for diagnosis of cytomegal ovirus disease in HIV infected adults

Background: Cytomegalovirus (CMV) infection is frequent in HIV adults. It is unknown usefulness of quantitative methods for diagnosing the CMV disease in Chilean patients. Aim: To determine the performance of antigenemia and real time polymerase chain reaction (rtPCR) in the diagnosis of CMV disease in Chilean HIV adults. Method: Detection of CMV by viral isolation (AVR), antigenemia and quantitative rtPCR in HIV adults. Results: The 102 adults with suspected CMV disease had lower LTCD4 count and higher HIV viral load than 77 patients without suspicion (p < 0.05). Antigenemia and PCR were positive in 47 (46.1%) and 37 (36.3%) adults with clinical suspicion and in 2 (2.6%) and 4 (5.2%) of 77 without suspicion. The sensitivity, specificity, positive and negative predictive value of antigenemia and RPCtr were 92%, 80%, 72% and 95% and 72%, 95%, 92% and 80%, respectively. The cutoff values were ≥ lcell (+) and ≥ 5.5 log10 copies/2 x 10(6) cells. CMV was isolated in 6/179 patients (3.4%), all symptomatic. Conclusión: Positivity of antigenemia and rtPCR are similar for diagnosing CMV disease in Chilean HIV adults. AVR is inappropriate as a gold standard for its low performance.

Introducción: La infección por citomegalovirus (CMV) es frecuente en adultos con virus de inmunodeficiencia humana (VIH). No se ha establecido la utilidad de los métodos cuantitativos para diagnosticar enfermedad por CMV en pacientes chilenos. Objetivo: Determinar la positividad de antigenemia y reacción de polimerasa en cadena en tiempo real (RPC-TR) en el diagnóstico de enfermedad por CMV en adultos chilenos con infección por VIH. Metodología: Se detectó CMV mediante aislamiento viral rápido (AVR), antigenemia y reacción de polimerasa en cadena en tiempo real (RPC-TR) cuantitativa en adultos infectados por VIH, con y sin sospecha de enfermedad por CMV. Resultados: El recuento de LT CD4 fue menor y mayor la carga de VIH en 102 sintomáticos respecto a 77 asintomáticos (p < 0,05). La antigenemia y la RPC-TR fueron positivas en 46 y 36% de los enfermos y en 3 y 5% de los asintomáticos respectivamente. La sensibilidad, especificidad, valor predictor positivo y negativo de la antigenemia y la RPC-TR fueron 92%, 80%, 72% y 95% y 72%, 95%, 92% y 80%, respectivamente. Los valores de corte fueron ≥ 1 núcleo (+) y ≥ 5,5 log10 copias/2 x 10(6) céls. Se aisló CMV en 3,4%, todos los sintomáticos. Conclusión: La antigenemia y la RPC-TR tienen una positividad similar para diagnosticar enfermedad por CMV en adultos chilenos con infección por VIH. El AVR es inapropiado como referencia por su baja positividad.

Comparison of Quantitation of Cytomegalovirus DNA by Real-Time PCR in Whole Blood with the Cytomegalovirus Antigenemia Assay

BACKGROUND: Quantitation of cytomegalovirus (CMV) DNA using real-time PCR has been utilized for monitoring CMV infection. However, the CMV antigenemia assay is still the 'gold standard' assay. There are only a few studies in Korea that compared the efficacy of use of real-time PCR for quantitation of CMV DNA in whole blood with the antigenemia assay, and most of these studies have been limited to transplant recipients. METHOD: 479 whole blood samples from 79 patients, falling under different disease groups, were tested by real-time CMV DNA PCR using the Q-CMV real-time complete kit (Nanogen Advanced Diagnostic S.r.L., Italy) and CMV antigenemia assay (CINA Kit, ArgeneBiosoft, France), and the results were compared. Repeatedly tested patients were selected and their charts were reviewed for ganciclovir therapy. RESULTS: The concordance rate of the two assays was 86.4% (Cohen's kappa coefficient value=0.659). Quantitative correlation between the two assays was a moderate (r=0.5504, P<0.0001). Among 20 patients tested repeatedly with the two assays, 13 patients were transplant recipients and treated with ganciclovir. Before treatment, CMV was detected earlier by real-time CMV DNA PCR than the antigenemia assay, with a median difference of 8 days. After treatment, the antigenemia assay achieved negative results earlier than real-time CMV DNA PCR with a median difference of 10.5 days. CONCLUSIONS: Q-CMV real-time complete kit is a useful tool for early detection of CMV infection in whole blood samples in transplant recipients.

Detección precoz de infección por citomegalovirus en pacientes sometidos a trasplante alogéneico de precursores hematopoyéticos por reacción de polimerasa en cadena cuantitativa en tiempo real / Early detection of cytomegalovirus infection in allogeneic hematopoietic stem cell transplant patients by real time-quantitative PCR

Introduction: CMV pp65-antigenemia (antigenemia) has been used for monitoring CMV viremia in allogeneic hematopoietic stem cell transplant (aHSCT) recipients. Recently, real time quantitative PCR (RT-qPCR ) has been used as a better approach than antigenemia for CMV diagnosis. The objective of this study was to assess the correlation of CMV viremia between RT-qPCR and antigenemia in aHSCT patients. Material and Methods: Observational prospective study of all aHSCT patients during 10 months in our center. CMV RT-qPCR in whole blood was performed weekly from day +7 to +100 after aHSCT. Simultaneous antigenemia was performed from engrafment to day +100. Concordance between both assays was evaluated. Results: Eighteen patients were included. In 120 simultaneous samples, 96 were concordant by both methods (80%). Kappa coefficient was 0.583. In 42% of cases without concordant results, patients were on antiviral therapy. Thirteen patients (72%) developed CMV infection (20 episodes). In 17 episodes, both the antigenemia and CMV RT-qPCR were positive. CMV RT-qPCR was detectable 1-2 weeks before antigenemia in 45% of the episodes. Conclusion: Both methods had a moderate concordance and CMV RT-qPCR detects CMV reactivations earlier than antigenemia, especially in neutropenic patients.

Introducción: La antigenemia pp65 (antigenemia) ha sido utilizada para monitorizar viremia de citomegalovirus (CMV) en pacientes sometidos a trasplantes alogeneicos de precursores hematopoiéticos (TPHa). Recientemente, la reacción de polimerasa en cadena cuantitativa en tiempo real (en inglés RT-qPCR) se ha usado como una mejor aproximación al diagnóstico de infección por CMV. El objetivo de este estudio fue evaluar la correlación de viremia por CMV a través de RT-qPCR con antigenemia, en pacientes que han recibido TPHa. Material y Métodos: Estudio prospectivo, observacional, de los pacientes sometidos a TPHa durante 10 meses. Se realizó RT-qPCR de CMV en sangre total semanalmente desde el día +7 al+100 después del trasplante y antigenemia en forma simultánea desde el prendimiento hasta el día +100. Se evaluó la concordancia entre ambos ensayos. Resultados: Dieciocho pacientes fueron incluidos. En 120 muestras simultáneas, 96 fueron concordantes por ambos métodos (80%). El coeficiente Kappa fue 0,583. En los casos no concordantes, el 42% se encontraba en terapia antiviral. Trece pacientes (72%) desarrollaron infección por CMV (20 episodios). En 17 episodios, ambos ensayos fueron positivos. La carga viral fue detectable 1-2 semanas antes que la antigenemia en 45% de los episodios. Conclusión: Existe una buena correlación entre ambas técnicas y la RT-qPCR detecta más precozmente que la antigenemia las reactivaciones de CMV, especialmente en pacientes neutropénicos.

Vírus da leucemia felina: análise da classificação da infecção, das técnicas de diagnóstico e da eficácia da vacinação com o emprego de técnicas sensíveis de detecção viral / Feline leukemia virus: infection outcomes, diagnostic techniques and vaccine efficacy analysis employing sensitive techniques of virus detection

O Vírus da leucemia felina (FeLV) pertence à família Retroviridae, gênero Gammaretrovirus. Diferentemente de outras retroviroses, uma parcela dos gatos jovens e adultos exposta ao FeLV não apresenta antigenemia/viremia, de acordo com as técnicas convencionais de detecção viral, como isolamento em cultivo celular, imunofluorescência direta e ELISA. O emprego de técnicas de maior sensibilidade para detecção e quantificação viral, como o PCR quantitativo, permitiu a identificação de animais positivos para a presença de DNA proviral e RNA na ausência de antigenemia/viremia e, com isso, um refinamento da análise das diferentes evoluções da infecção. Assim, reclassificou-se a patogenia do FeLV em 4 categorias: infecção abortiva, regressiva, latente e progressiva. Foi possível também detectar DNA proviral e RNA em animais considerados imunes ao FeLV após vacinação. Diante disso, os objetivos desta revisão de literatura foram demonstrar as implicações da utilização de técnicas sensíveis de detecção viral na interpretação e classificação da infecção do FeLV e rever as técnicas de detecção do vírus para fins de diagnóstico. Além disso, apresentar os resultados referentes à eficácia da vacinação contra o FeLV com a utilização dessas técnicas.

Feline leukemia virus (FeLV) belongs to the Retroviridae family, genus Gammaretrovirus. Unlike other retroviruses, a portion of FeLV exposed animals eliminates antigenemia/viremia, according to convectional techniques of virus detection, such as isolation in cell culture, direct fluorescent antibody test and ELISA. The use of more sensitive techniques to detect and quantify viruses enabled the detection of proviral DNA and RNA in cats with undetectable antigenemia/viremia, and thus the refinement of the different infection outcomes analysis. As a result, FeLV pathogenesis was reclassified in 4 categories: abortive, regressive, latent and progressive infections. It was also demonstrated the detection of proviral DNA and RNA in cats believed to be immune to infection after vaccination. Therefore, the objectives of this review were to demonstrate the implications of the use of sensitive techniques for viral detection in the interpretation and classification of FeLV infection and reconsider the techniques for FeLV diagnostic purposes. In addition, it was presented the results concerning the effectiveness of FeLV vaccination with the use of these techniques.

Comparison of the performance of polymerase chain reaction and pp65 antigenemia for the detection of human cytomegalovirus in immunosuppressed patients / Comparação de métodos para detecção de infecção por citomegalovírus em pacientes imunossuprimidos

INTRODUCTION: Human cytomegalovirus (HCMV) is often reactive in latently infected immunosuppressed patients. Accordingly, HCMV remains one of the most common infections following solid organ and hemopoietic stem cell transplantations, resulting in significant morbidity, graft loss and occasional mortality. The early diagnosis of HCMV disease is important in immunosuppressed patients, since in these individuals, preemptive treatment is useful. The objective of this study was to compare the performance of the in-house qualitative polymerase chain reaction (PCR) and pp65 antigenemia to HCMV infection in immunosuppressed patients in the Hospital de Clínicas of Porto Alegre (HCPA). METHODS: A total of 216 blood samples collected between August 2006 and January 2007 were investigated. RESULTS: Among the samples analyzed, 81 (37.5 percent) were HCMV-positive by PCR, while 48 (22.2 percent) were positive for antigenemia. Considering antigenemia as the gold standard, sensitivity, specificity, positive predictive values and negative predictive values for PCR were 87.5 percent, 76.8 percent, 51.8 percent and 95.5 percent respectively. CONCLUSIONS: These results demonstrated that qualitative PCR has high sensitivity and negative predictive value (NPV). Consequently PCR is especially indicated for the initial diagnosis of HCMV infection. In the case of preemptive treatment strategy, identification of patients at high-risk for HCMV disease is fundamental and PCR can be useful tool.

INTRODUÇÃO: O citomegalovírus humano (HCMV), causador de infecção latente, reativa com frequência em pacientes imunossuprimidos. Portanto, o HCMV permanece uma das infecções mais comuns após transplantes de órgãos sólidos e de células hematopoiéticas resultando em significativa morbidade, perda do enxerto e ocasional mortalidade. Assim, o diagnóstico precoce para uma terapia preventiva é de grande importância. Este estudo visa comparar o desempenho dos métodos PCR qualitativo in-house e antigenemia pp65 para o diagnóstico de infecção por CMV em pacientes imunossuprimidos do Hospital de Clínicas de Porto Alegre. MÉTODOS: O estudo foi realizado em 216 amostras de sangue total (EDTA) coletadas de 85 pacientes, entre agosto de 2006 e janeiro de 2007. RESULTADOS: Dentre as 216 amostras analisadas, 81 (37,5 por cento) amostras apresentaram resultados positivos na PCR, enquanto 48 (22,2 por cento) apresentaram resultados positivos na antigenemia. A sensibilidade, especificidade, valor preditivo positivo e valor preditivo negativo para a PCR, considerando antigenemia como padrão foram 87,5 por cento, 76,8 por cento, 51,8 por cento e 95,5 por cento, respectivamente. CONCLUSÕES: Estes resultados demonstraram que a PCR tem alta sensibilidade e valor preditivo negativo. Consequentemente PCR é especialmente indicada para o diagnóstico inicial de infecção por HCMV. No caso da estratégia de terapia preventiva, a identificação de pacientes com alto risco para a doença por HCMV é fundamental e a PCR pode ser uma ferramenta útil.

Comparación de las técnicas de reacción de polimerasa en cadena en tiempo real y antigenemia para la detección de citomegalovirus en sangre de niños sometidos a trasplantes / Comparison of real-time polymerase chain reaction and antigenemia assay to detect cytomegalovirus in pediatric transplants

Background: Cytomegalovirus (CMV) infections are an important cause of morbidity and mortality in transplant recipient. To date, the antigenemia assay is the most used technique for diagnostic and management of CM V infections. However, quantification of CMV viral load by real time polymerase chain reaction (RT-PCR) has becoming the method of choice to detect CMV in a rapid, sensitive and specific manner. Objective: To compare antigenemia and RT-PCR assays in the detection of CMV in blood sample from solid organ and bone marrow transplant (BMT) in children attended at the Dr. Luis Calvo Mackenna Hospital. Methods: In a prospective study, we detect the presence of CMV in blood sample by RT-PCR and antigenemia assays. Results: We analyzed 219 blood samples from 68 children subjected to kidney, liver and BMT. Out of 219 samples analyzed, 147 were negative and 33 were positive for CMV by both techniques. Thirty-seven samples were positive only by RT-PCR and 2 by antigenemia. Considering the antigenemia as a reference, RT-PCR shows 94 percent, 80 percent, 34 percent and 99 percent sensitivity, specificity, positive and negative predictive values, respectively. The kappa coefficient between both techniques was 0.528. Conclusion: Quantitative determination of CMV viral load by RT-PCR is a sensitive technique with excellent negative predictive valué compared to antigenemia. Our results support the use of RT-PCR as a technique that might facilítate the diagnostic and treatment of active CMV infection in pediatric transplants.

Antecedentes: Las infecciones por citomegalovirus (CMV) corresponden a una importante causa de morbilidad y mortalidad en pacientes sometidos a trasplantes. Hasta la fecha, la detección de CMV en células infectadas en sangre periférica mediante la técnica de inmunofluorescencia (antigenemia) es la más utilizada para el diagnóstico y monitorización de la infección por este agente. Sin embargo, en el último tiempo la cuantificación de la carga de ácido nucleico (ADN) de CMV en sangre mediante la técnica de reacción de polimerasa en cadena en tiempo real (RPC-TR) ha permitido la detección de CMV de forma más rápida, sensible y específica. Objetivos: Comparar las técnicas de antigenemia y RPC-TR para la detección de CMV en sangre en niños sometidos a trasplante de órganos sólidos y trasplante de precursores hematopoyéticos (TPH) en el Hospital Dr. Luis Calvo Mackenna. Metodología: En un estudio prospectivo de seguimiento preventivo de reactivación se detectó la presencia de CMV en muestras de sangre utilizando las técnicas de RPC-TR y antigenemia. Resultados: Se analizaron 219 muestras de sangre, correspondiente a 68 niños sometidos a trasplante de hígado, riñon y TPH. De las muestras analizadas, 147 fueron negativas y 33 positivas para CMV utilizando ambas técnicas. Treinta y siete muestras resultaron ser positivas sólo por RPC-TR y dos sólo por antigenemia. Tomando en cuenta la antigenemia como referencia, la RPC-TR mostró una sensibilidad, especificidad, valor predictor positivo y negativo de 94 por ciento, 80 por ciento, 34 por ciento y 99 por ciento, respectivamente. El índice de concordancia entre ambas técnicas tuvo un valor de kappa = 0,528. Conclusión: La determinación cuantitativa de ADN de CMV por RPC-TR es una técnica sensible, con un gran valor predictor negativo comparada con la antigenemia. Los resultados obtenidos en este trabajo apoyan el uso de RPC-TR para el diagnóstico y tratamiento oportuno de las infecciones activas por CMV en niños sometidos a trasplantes.

Fluorescence quantitative PCR in diagnosing and treating infantile cytomegalovirus infection / 国际儿科学杂志

Fluorescence quantitative PCR (FQ-PCR) is a more sensitive and specific method to diagnose and monitor cytomegalovirus(CMV) infection, and it is closely correlated with pp65 antigenemia levels. Measuring the CMV-DNA levels in infant urine and blood can be helpful to regulate the treatment and monitor the effects of the antivirus therapy.

Quantification of CD8+CD38+ T lymphocytes by flow cytometry does not represent a good biomarker to monitor the reactivation of cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation

BACKGROUND: Infection/reactivation of cytomegalovirus is a major cause of morbidity and mortality in immunocompromised transplant patients. It has already been observed in kidney and liver transplantation patients that cytomegalovirus disease is accompanied by significant increases in circulating CD8+CD38+ T lymphocytes. There are no reports that study CD8+CD38+ T lymphocytes to monitor/diagnose cytomegalovirus disease in hematopoietic stem cell transplantation patients. OBJECTIVE: The aim of this study was to evaluate some cellular activation markers on circulating mononuclear cells (CD38 and HLA-DR) in patients submitted to hematopoietic stem cell transplantation and to establish any correlation with cytomegalovirus disease as diagnosed by antigenemia. METHODS: Blood samples of 15 transplant patients were analyzed by flow cytometry using anti-CD3, anti-CD4, anti-CD8, anti-CD38, CD16, CD56 and anti-HLA-DR monoclonal antibodies and the results were evaluated in respect to cytomegalovirus antigenemia measured by indirect immunofluorescence. Minitab for Windows was used for statistical analysis and a p-value < 0.05 was considered significant. RESULTS: Patients with positive antigenemia did not show any significant increase in the percentages of cells expressing the CD38 or HLADR activation markers when compared to patients with negative antigenemia. On the contrary, all patients showed high percentages of these cells independent of the presence of cytomegalovirus disease. CONCLUSIONS: This study suggests that the investigation of these lymphocyte sub-populations in patients submitted to hematopoietic stem cell transplantation does not seem to contribute to the early identification of cytomegalovirus disease.

Comparison of a rapid cytomegalovirus pp65 antigenemia assay revealed by immunofluorescence to an in-house assay revealed by immunoperoxidase for diagnosis in solid organ transplant recipient patients

Cytomegalovirus (CMV) antigenemia is still one of the two major assays available for diagnosis and monitoring of CMV infections. A commercial rapid test recently available in Brazil for quantification of human cytomegalovirus pp65 antigenemia revealed by immunofluorescence technique was compared with the original in-house method revealed by immunoperoxidase in patients receiving solid organ transplants. Of 80 blood samples tested for CMV antigenemia, 34 (42.5 percent) were positive: commercial assay detected 33 (97 percent) and in-house assay detected 20 (58.8 percent) samples. The numbers of positive cells in the two assays were different, with a median of 4.5 and 12 positive cells obtained by in-house and commercial kit, respectively. Discrepancies between assays occurred in 15 specimens from patients with low-grade antigenemia (median 6 positive cells). The assay-time was reduced in approximately 50 percent compared to in-house methodology. In conclusion, besides comparable results obtained for both assays, the commercial antigenemia assay provides more rapid and sensitive results.

Active human Cytomegalovirus infection and Glycoprotein B genotypes in Brazilian pediatric renal or hematopoietic stem cell transplantation patients

A prospective analysis of active Human Cytomegalovirus infection (HCMV) was conducted on 33 pediatric renal or hematopoietic stem cell post-transplant patients. The HCMV-DNA positive samples were evaluated for the prevalence of different gB subtypes and their subsequent correlation with clinical signs. The surveillance of HCMV active infection was based on the monitoring of antigenemia (AGM) and on a nested polymerase chain reaction (N-PCR) for the detection of HCMV in the patients studied. Using restriction analysis of the gB gene sequence by PCR-RFLP (Restriction Fragment Length Polymorphism), different HCMV strains could be detected and classified in at least four HCMV genotypes. Thirty-three pediatric recipients of renal or bone marrow transplantation were monitored. Twenty out of thirty-three (60.6%) patients demonstrated active HCMV infection. gB1 and gB2 genotypes were more frequent in this population. In this study, we observed that gB2 had correlation with reactivation of HCMV infection and that patients with mixture of genotypes did not show any symptoms of HCMV disease. Future studies has been made to confirm this.

Active human Cytomegalovirus infection and Glycoprotein B genotypes in Brazilian pediatric renal or hematopoietic stem cell transplantation patients

A prospective analysis of active Human Cytomegalovirus infection (HCMV) was conducted on 33 pediatric renal or hematopoietic stem cell post-transplant patients. The HCMV-DNA positive samples were evaluated for the prevalence of different gB subtypes and their subsequent correlation with clinical signs. The surveillance of HCMV active infection was based on the monitoring of antigenemia (AGM) and on a nested polymerase chain reaction (N-PCR) for the detection of HCMV in the patients studied. Using restriction analysis of the gB gene sequence by PCR-RFLP (Restriction Fragment Length Polymorphism), different HCMV strains could be detected and classified in at least four HCMV genotypes. Thirty-three pediatric recipients of renal or bone marrow transplantation were monitored. Twenty out of thirty-three (60.6 percent) patients demonstrated active HCMV infection. gB1 and gB2 genotypes were more frequent in this population. In this study, we observed that gB2 had correlation with reactivation of HCMV infection and that patients with mixture of genotypes did not show any symptoms of HCMV disease. Future studies has been made to confirm this.

Comparison of Quantitative Cytomegalovirus Real-time PCR in Whole Blood and pp65 Antigenemia Assay: Clinical Utility of CMV Real-time PCR in Hematopoietic Stem Cell Transplant Recipients

Successful preemptive therapy for cytomegalovirus (CMV) infection in transplant patients depends on the availability of sensitive, specific, and timely diagnostic tests for CMV infection. Although the pp65 antigenemia assay has been widely used for this purpose, real-time quantification of CMV DNA has recently been recognized as an alternative diagnostic approach. However, the guidelines for antiviral therapy based on real-time quantitative polymerase chain reaction (RQ-PCR) have yet to be established. From November 2004 to March 2005, a total of 555 whole blood samples from 131 hematopoietic stem cell transplant (HSCT) recipients were prospectively collected. RQ-PCR was conducted using an Artus(R) CMV LC PCR kit (QIAGEN). Both qualitative and quantitative correlations were drawn between the two methods. Exposure to the antiviral agent influenced the results of the two assays. Additionally, the discrepancy was observed at low levels of antigenemia and CMV DNA load. Via ROC curve analysis, the tentative cutoff value for preemptive therapy was determined to be approximately 2x10(4) copies/mL (sensitivity, 80.0%; specificity, 50.0%) in the high risk patients, and approximately 3x10(4) copies/mL (sensitivity, 90.0%; specificity, 70.0%) in the patients at low risk for CMV disease. Further study to validate the optimal cutoff value for the initiation of preemptive therapy is currently underway.