Evaluación de la estabilidad del sistema de diagnóstico inmunoenzimático DAVIH VIH-2 / Evaluation of the stability of the immunoenzymatic diagnostic system DAVIH VIH-2

Introducción: el estudio de la estabilidad de los componentes y el producto terminado constituye un importante requisito regulatorio en los diagnosticadores. Objetivo: realizar un estudio de estabilidad en tiempo real durante doce meses del sistema inmunoenzimático (ELISA) DAVIH VIH-2. Métodos: se realizó un estudio de estabilidad en tiempo real durante doce meses en tres lotes del diagnosticador DAVIH VIH-2, ELISA indirecto diseñado para la detección de anticuerpos contra el virus de inmunodeficiencia humana tipo 2 en suero o plasma humano. Se controlaron los requisitos de calidad de los componentes de acuerdo a sus especificaciones. Se estudió la normalidad de valores de densidad óptica/valor límite y la homogeneidad de las medias y varianzas mediante las dócimas de Grubbs y Cochran. Se estimó la precisión en los controles positivo y negativo del sistema y en seis muestras con diferente reactividad al virus de inmunodeficiencia humana tipo 2 mediante el cálculo del coeficiente de variación y se confeccionaron las cartas de control de los valores de las medias de densidad óptica respecto al tiempo. Resultados: los requisitos de calidad de cada componente se cumplieron durante 12 meses, excepto las características funcionales del conjugado a partir de los seis meses. Los valores en las dócimas de Grubbs y Cochran fueron menores que los valores críticos tabulados para α del 1 y 5 por ciento por lo que existió homogeneidad en las medias y las varianzas en todo el periodo. El coeficiente de variación se mantuvo inferior al 10 por ciento excepto en las muestras con reactividad media y baja, mientras que en las cartas de control, los valores de densidad óptica se mantuvieron en el límite de la media ±2 desviaciones estándar hasta el noveno mes(AU)

Seroprevalence of human immunodeficiency virus-2 in and around Amritsar.

A total of 14555 serum samples collected between January, 2001 to April, 2006 were screened for HIV infection. Antibodies to HIV-1/ HIV-2 were present in 985 (6.76%) of which 964 (97.86%) and 2 (0.22%) were positive for HIV-1 and HIV-2 alone respectively and 19 (1.92 %) for both HIV-1 and HIV-2. Of the 21 in whom HIV-2 infection was detected (alone and dual), 19 (90.5%) were in the age group of 21-40 years and 2 were children below the age of 11 years. Predominantly mode of transmission in them was heterosexual (85.71%) while the 2 children (9.53%) had most probably got the infection through perinatal route. Nine (42.85%) were asymptomatic and 12 (57.15%) clinically presented with chronic diarrhoea (5), prolonged fever (4) and symptoms related to sexually transmitted diseases (3). Opportunistic infections like Oral candidiasis was observed in 3 and pulmonary tuberculosis in 2.

Glycaemic consequences of HIV and highly active antiretroviral therapy: a pilot study and review of literature.

The metabolic consequences of HIV and AIDS are accentuated in the setting of highly active antiretroviral therapy. Peripheral lipodystrophy, central adiposity, hyperlipidaemia, insulin resistance and diabetes mellitus are frequent associations of protease inhibitor containing highly active antiretroviral therapy regimens. Ninety patients aged 25-50 years (males 52, females 38), seropositive for HIV 1 and 2 or both were selected to see the glycaemic profiles in asymptomatic early HIV disease with CD4 counts > 100/microl and to compare this with the glycaemic profile of (a) advanced HIV disease (CD4 counts < 200/microl), not on highly active antiretroviral therapy and (b) advanced HIV disease (CD4 counts < 200/microl), on uninterrupted non-protease inhibitor highly active antiretroviral therapy > 6 months. All the patients were grouped into 3: (1) Group A: CD4 counts > 500/microl (n=37), highly active antiretroviral therapy naive, (2) group B: CD4 counts < 200/microl (n=21), not on highly active antiretroviral therapy, and (3) group C: CD4 counts < 200/microl, receiving uninterrupted non-protease inhibitor based highly active antiretroviral therapy for > 6 months (n=32). The fasting blood glucose, glycosylated Hb (HbA1c) levels, were measured in all the patients in 3 groups and significance of difference between means was calculated among various groups. Body weight and waist-hip ratio were also measured. The results were analysed and compared with other studies.

Evidence for HIV-2 infection in Nepal.

Assessment of the presence and prevalence of HIV-2 antibodies in patients attending the Universal College of Medical Sciences Teaching Hospital, Bhairahawa, western Nepal was done. A total of 1534 patients sera were screened for the presence of HIV-1 and HIV-2 antibodies from March 2000 to May 2003. A total of 3 (0.2%) patients were found to be sero-positive for HIV-2 antibodies. Out of the above three patients, 1 (0.1%) was infected with HIV-2 only and the remaining 2 (0.1%) were infected with HIV-1 and HIV-2 both. This evidence of the presence of HIV-2 presence implicates serious outcomes as HIV-2 has not been reported from hospital patients in Nepal.

HIV-2 infection in Thailand.

Neither the seroprevalence of HIV-2 nor the sensitivity of enzyme immunoassays for the detection of antibodies to this retrovirus have been defined in Thailand. We, therefore, Investigated these enigmas using banked sera previously screened for HIV-1 by a test that did not distinguish between HIV-1 and HIV-2. All 1,013 HIV-seroreactive specimens were positive to HIV-1 on retesting, and 740 (73%) were reactive to both HIV-1 and HIV-2. The thirty-six samples that reacted with HIV-2 at a titer of > or = 1:4,096 were further tested to discriminate between HIV-1 and HIV-2 by immunoblot assays incorporating HIV-2 recombinant proteins. One specimen was untypeable, but all others were determined to be HIV-1. Seventy-three percent of sera from Thai HIV-1 infected subjects cross-reacted with HIV-2, but not a single case of HIV-2 infection could be confirmed. The finding suggests low prevalence of HIV-2 infection in Thailand and that current testing for HIV-2 antibody is not necessary in Thai population.

p24 antigen screening to reduce the risk of HIV transmission by seronegative bone allograft donors.

BACKGROUND: During the last decade, more than 2000 bone allografts harvested from 888 donors and processed by the Queensland Bone Bank have been transplanted in over 1500 patients in Australia and New Zealand. A strict protocol to eliminate HIV transmission by fresh frozen allografts is followed; and not a single case of HIV transmission has been reported. METHODS: All donors were screened and strict donor exclusion criteria were used. All donor blood samples were subjected to double testing including antibody to HIV-1, HIV-2 and HTLV-1 and p24 antigen. The allografts negative for these tests were subjected to processing, including removal of extraneous tissue, pulsatile lavage to remove marrow elements, and immersion in 97% alcohol for 20 minutes. Allografts were subjected to 25 cGy irradiation before transplantation. RESULTS: Allografts were retrieved from a total of 950 donors and 51 were discarded after screening for contamination by organisms other than HIV-1. Eleven donors negative for HIV-1 antibodies tested positive for p24 antigen and were discarded. Allografts from donors testing negative for both the tests (n = 888) were irradiated and used for transplantation. CONCLUSIONS: Routine p24 antigen testing and irradiation of allograft should be mandatory for bone banks, especially those freezing fresh allografts. p24 antigen testing is inexpensive, rapid and easy. Certain guidelines must be followed to avoid misleading results of p24 testing.

Increasing prevalence of HIV-2 and dual HIV-1-2 infections among patients attending various outdoor patient departments in Mumbai (Bombay).

Between 1993-96, a serological study was carried out for differentially identifying HIV-1 and HIV-2 infections among the high risk group persons attending the various outdoor patient departments of BYL Nair Municipal Hospital, Mumbai. This study indicates that although HIV-1 is still the predominant virus among the high risk HIV infected persons in Mumbai, dual HIV-1-2 infections are increasing especially among promiscuous heterosexuals and female commercial sex workers. Increases in HIV-2 infections were observed later than dual HIV-1-2 infections, indicating that it is the HIV-1 infected individuals who through continued high risk behavior got infected by HIV-2.

Avaliaçäo do desempenho de uma prova rápida para diagnóstico da infecçäo pelo HIV / Diagnosis of HIV infection. Performance evaluation of a rapid HIV test

Avaliamos o desempenho do teste denominado "Simplex HIV & II Rapid Test", proposto para diagnosticar, de maneira muito simples e rápida, a infecçäo por HIV-1/2. A fim de realizar a prova imunogromatográfica, usamos saliva. O complexo antígeno-anticorpo formando é revelado por sistema indicador. Verificamos resultados decepcionantes, tendo sido expressivas as porcentagens de falso-negativos e de falsos-positivos, imunocompatíveis com o que se deseja em tarefas assistenciais e epidemiológicas. Alertamos para a necessidade de näo adotar procedimentos qualificados como rápidos e singelos sem antes analisar as qualidades deles, sobretudo quanto às sensibilidades e especificidades. Julgamos também indispensável estipular oficialmente as situaçöes nas quais poderäo ser utilizados.

HIV in intensive care--a 3 years experience.

A three year prospective study of a total of 62 critically ill HIV patients in MICU showed a rising percentage from 0.86 in 1992 to 3.17 in 1994. Four major presentations were observed, neurological-20 patients (32.5%), sepsis syndrome-18 (29%), poisoning-10 (16.1%) and miscellaneous-14 (22.6%). Acute poisoning emerged as the most important preventable indication for MICU admissions. Interventions like CVP and haemodynamic monitoring-25 patients, endotracheal intubation-18, mechanical ventilation-14, tracheostomy-3, haemodialysis-3 were done when indicated. The mortality of the 14 ventilated patients was high at 92.9% compared to the overall HIV mortality of 46.8%. This study shows that critically ill HIV patients do deserve intensive care management with optimum infection control precautions. Survival of 53.2% is noteworthy in a resource stretched set up.

An in vitro qualitative assay for the detection of antibodies to HIV type 1/2 contained in human saliva.

There is ample evidence that saliva contains secretory antibody against most infections. Therefore, saliva has been recommended as a non invasive, safe and effective alternative to serum, for HIV antibody testing. The present study attempted comparative evaluation of antibody detection by serum and saliva specimens in laboratory by ELISA and Western Blot for diagnosis of HIV infection in the Indian situation. From a study of 42 test sera it is concluded that test apart from its simplicity and reproducibility, is almost free from any false positive and false negative reactions.

Respuesta inmune humoral hacia VIH-2 en México / Humoral immune response to HIV-2 in Mexico

Objetivo. Estudiar las reacciones hacia antígenos de VIH-2 de sueros mexicanos VIH-1 positivos, en relación con la vía de transmisión y el estado clínico de los individuos infectados. Material y métodos. Se estudiaron 654 sueros (492 VIH-1 positivos y como controles 162 VIH-1 negativos). Se preparon Inmuno blots (IB) con antígenos semipurificados de MS-VIH-2 y de IIIb/LAV-VIH-1 y se corrieron en ambos todas las muestras de suero. Resultados. En el análisis de los IB de los sueros VIH-1 positivios se encontró que 79 por ciento (388/492) presentaron reactividad con, por lo menos, una proteína VIH-2; 71 por ciento (352/492) de los sueros reconocen la proteína de cápside p24; la glicoproteína transmembranal de VIH-2 es reconocida por 24 por ciento (119/492) de los sueros y 9 por ciento (44/492) reconocieron la glicoproteína externa de este retrovirus. La reactividad con VIH-2 de sueros VIH-1 positivos está significativamente asociada a la vía de adquisición de la infección (81 por ciento en vía sexual contra 39 por ciento en vía sanguínea) y al estado clínico (84 por ciento en pacientes asintomáticos o con linfadenopatía contra 31 por ciento en pacientes con SIDA). Se descartó la posible infección con los dos tipos de VIH por medio del ensayo comercial Liatek (Organon Teknica). Conclusiones. Se propone como hipótesis que las cepas introducidas originalmente en nuestro país a través de las dos vías principales de transmisión son de orígenes diferentes

Objective. To study the reactions of Mexican HIV-1 positive sera to HIV-2 antigens, and their relation to the mode of ransmission and the clinical status of infected individuals. Material and Methods. Six-hundred and fifty-four sera samples collected in Mexico were tested using HIV-2 immunoblot (IB) techniques; 492 samples were from HIV-1 positive cases and 162 from HIV-1 negative controls. Results. Seventy-nine percent (388/492) of the HIV-1 reactive sera showed reactivity with at least one HIV-2 protein: 71% (352/492) recognized the capsid protein p24, 24% (119/492) the transmembrane glycoprotein and 9% (44/492) the external glycoprotein of HIV-2. Considering the transmission mechanism, HIV-2 reactivity occurred in 81% (324/401) of the sexually infected patients, and only in 39% (16/41) of people infected through blood products. Ten highly reactive gp32 HIV-2 sera samples were titrated and results showed that reactivity with HIV-1 gp41 was always higher than that to HIV-2 gp32. HIV-1-HIV-2 dual infection was discarded by negative results with the commercial assay Liatek HIV 1+2. Conclusions. We propose that the serological cross-reactivity found can be due to a possible initial introduction in Mexico of two different viral strains through the two main ransmission routes and that the strains circulating in sexually infected individuals are more similar to the HIV-2 strains, at least with respect to their glycoproteins, than the HIV-1 strains predominant in other countries.

HIV antibodies among intravenous drug users in Bahrain.

A 12-month study was conducted to identify risk factors for human immunodeficiency virus (HIV) infections among intravenous drug users (IDU) attending drug rehabilitation clinic of the Psychiatric Hospital, Manama, Bahrain. Patients provided demographic and behavioural information based on a questionnaire. Two hundred and forty male IDUs participated in the study on voluntary basis. The seroprevalence of HIV was 21.1 per cent. The presence of HIV antibody was associated with educational status, frequency of injecting drugs and needle sharing.

Seropositividad para VIH-1 y VIH-2 en donadores de sangre en el Hospital General de Ticomán S.S / Prevalence of HIV-1 and HIV-2 in voluntary blood donnors at the Ticoman General Hospital

En un estudio observacional, longitudinal y abierto, se valoró la seroprevalencia a los virus de la inmunodeficiencia humana 1 y 2 en 76 donadores voluntarios de sangre en el Hospital General de Ticomán S.S. De los 76 sujetos estudiados, 1 heterosexual promiscuo fue positivo al VIH-1, todos los donadores fueron seronegativos al VIH-2. Nuestros resultados apoyan la baja prevalencia del VIH-1 en la población fuera de los grupos de riesgo, y aunque no hubo seropositividad al VIH-2, debe tenerse en mente la aparición de dicho virus en nuestro país en cualquier momento

Risco atual de transmissao de AIDS por transfusao / Actual risk of AIDS transmission by transfusion

Desde 1982 e sabida a possibilidade de transmissao da infeccao pelo HIV atraves da transfusao de sangue. Este risco hoje e muito menor, mas nao e ausente, quando as unidades a serem trasnfundidas sao testadas: uma em 60.000, testada negativa, transmite a infeccao nos Estados Unidos. No Brasil a prevalencia de doadores de sangue soropositivos para o anti HIV e 15 vezes maior: admitindo que as falhas de diagnostico da infeccao pelo individuo estar na "janela" sorologica serem iguais nos dois paises, o risco de pegar uma infeccao pelo HIV tomando unidade que testou negativa no Brasil vai de 1/2533 a 1/5000 e nao adianta fazer mais e mais testes para evitar isto. A unica maneira de melhorar esta situacao e mudar o perfil dos doadores, afastando da doacao os que realmente nao querem doar, e sim obter um teste anti HIV rapidamente e de graca - e para isto a melhor solucao e fazer sistemas de execucao rapidos e gratuitos deste exame disponiveis para a populacao, longe dos servicos de Hemoterapia e colheita de sangue.

The detection of HIV-2 infection in southern India.

To determine the prevalence of HIV-2 infection in southern India, we tested two sets of sera, selected from among the samples which had been collected between January 1988 and October 1990 from high risk subjects and tested for HIV-1 antibody. They were screened for HIV-2 antibody by ELISA and repeatedly reactive sera confirmed by HIV-2 Western blot and line immunoassay. In the first set of 604 sera, only one (0.16%) was positive for HIV-2. In the second set of 24 sera, selected on the basis of having indeterminate HIV-1 Western blot profiles, again one (4%) was positive for HIV-2. The two HIV-2 infected subjects were residents of Madras or Visakhapatnam. Residents of Vellore region constituted 88 and 75 per cent of the two sets of subjects; none was positive for HIV-2. Our results show the prevalence of HIV-2 in the port-cities of southern India. Since it will spread to other regions continuous monitoring for this infection is essential in order to determine when to establish HIV-2 screening in addition to the existing HIV-1 screening of donor blood for transfusion.

Comparative evaluation of HIV infected foreign students and Indian with AIDS in Chandigarh, India.

Out of a total of 1,600 foreign students who came to India between June 1989 and October 1990, 22 were seropositive for HIV-1. Ten showed antibodies to all the gene products. Antibodies to gp160 and p24 were present in all the seropositives while antibodies to p53, p15/17 were significantly higher in healthy seropositives than in patients with full blown AIDS. Absence of antibodies to p15/17 and p53 thus appeared to be a more sensitive criterion of end stage disease than absence of anti- p24 antibodies. When seropositive samples from African students were checked for HIV-2 antibodies by ELISA, 13/22 were found to be positive. Further, 2/10 Indians with full blown AIDS were also strongly positive for HIV-2. These data could be of relevance for formulating future strategies for population-based screening for HIV-2.

Production of monoclonal antibodies to human immunodeficiency virus type-2

The ROD strain of the human immunodeficiency virus type 2 (HIV-2) was used to produce monoclonal antibodies. Virus grown in CEM cells was partially purified by ultracentrifugation and solubilized in a buffer containing Triton X-100. BALB/c mice were inoculated intraperitoneally with 50 micrograms of solubilized virus preparations mixed 1:1 with complete Freund's adjuvant. Animals were boosted on day 28 and sacrificed on day 31. Spleen cells from the immunized animals were fused with SP20/Ag 14 myeloma cells and cultured in HAT medium. Following selection of the hybrids of interest by an HIV-2 ELISA procedure, hybridomas were cloned twice by limiting dilution. Six clones were found to produce antibodies that reacted with HIV-2 antigens as judged by ELISA. These antibodies were concentrated by ammonium sulfate precipitation, and analyzed by the Western blot procedure. Monoclonal antibodies specifically reactive to an HIV protein of 68 KD were obtained. These antibodies did not react with an HIV-2 band of 55 KD. These data showed that the monoclonal antibodies recognized the carboxy terminal region (the RNAse H domain) of the HIV-2 retrotranscriptase enzyme