RESUMO
BACKGROUND: Quantitative PCR to detect Pneumocystis jirovecii (Pj) is a new tool for the diagnosis of Pneumocystis jirovecii pneumonia (PJP). The yield of this technique, in cases of low fungal burden, when the standard technique using immunofluorescence (IF) is negative, needs to be evaluated. METHODS: We retrospectively reviewed the charts of all patients with a positive PCR but negative IF test (PCR+/IF-) in bronchoalveolar lavage (BAL) fluid performed over one year. We used an algorithm based on underlying immunosuppression, clinical picture, thoracic CT scan appearances, existence of an alternative diagnosis and the patient's outcome on treatment. Using this, each case was classified as probable PJP, possible PJP or colonization. RESULTS: Among the 416 BAL performed, 48 (12%) were PCR+/IF- and 43 patients were analyzed. Patients were mostly male (56%) with a median age of 60 years. Thirty-five (84%) were immunocompromised: 4 (9%) HIV-infected patients, 26 (60%) with hematologic or solid organ cancer, 3 (7%) were renal transplant recipients. Seven (16%) were classified as probable PPJ and 9 (21%) as possible PJP. Patients with a probable or possible PJP were more frequently admitted to the ICU (P<0.02) and had higher risk of death (P<0.01) when compared to those with colonization. Median PCR levels were very low and were not different between PJP or colonized patients (P=0.23). CONCLUSIONS: Among patients with a positive Pj PCR in BAL but with negative IF, only 37% had probable or possible PJP and PCR could not discriminate PJP from colonization.
Assuntos
Líquido da Lavagem Broncoalveolar/microbiologia , Infecções Fúngicas Invasivas/diagnóstico , Infecções por Pneumocystis/diagnóstico , Pneumocystis carinii/isolamento & purificação , Pneumonia por Pneumocystis/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real , Adulto , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Feminino , Infecções por HIV/complicações , Infecções por HIV/microbiologia , Humanos , Hospedeiro Imunocomprometido , Infecções Fúngicas Invasivas/microbiologia , Masculino , Pessoa de Meia-Idade , Neoplasias/complicações , Neoplasias/epidemiologia , Neoplasias/microbiologia , Infecções Oportunistas/diagnóstico , Infecções Oportunistas/microbiologia , Infecções por Pneumocystis/microbiologia , Infecções por Pneumocystis/patologia , Pneumocystis carinii/genética , Pneumonia por Pneumocystis/genética , Valor Preditivo dos Testes , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase em Tempo Real/normas , Estudos Retrospectivos , Transplantados/estatística & dados numéricosRESUMO
Pneumocystis jirovecii is the only fungus of its kind to be pathogenic in humans. It is primarily responsible for pneumonia (PJP). The key to understanding immune defences has focused on T-cells, mainly because of the HIV infection epidemic. Patients presenting with PJP all have a CD4 count below 200/mm(3). The introduction of systematic primary prophylaxis and the use of new anti-retroviral drugs have significantly reduced the incidence of this disease in the HIV-infected population, mainly in developed countries. The increasingly frequent use of corticosteroids, chemotherapy, and other immunosuppressive drugs has led to an outbreak of PJP in patients not infected by HIV. These patients presenting with PJP have more rapid and severe symptoms, sometimes atypical, leading to delay the initiation of a specific anti-infective therapy, sometimes a cause of death. However, the contribution of new diagnostic tools and a better understanding of patients at risk should improve their survival.
Assuntos
Infecções por Pneumocystis/epidemiologia , Pneumocystis carinii , Corticosteroides/efeitos adversos , Corticosteroides/uso terapêutico , Antineoplásicos/efeitos adversos , Doenças do Tecido Conjuntivo/complicações , Doenças do Tecido Conjuntivo/tratamento farmacológico , Quimioterapia Combinada , Diagnóstico Precoce , Soronegatividade para HIV , Humanos , Hospedeiro Imunocomprometido , Síndromes de Imunodeficiência/complicações , Fatores Imunológicos/efeitos adversos , Imunossupressores/efeitos adversos , Neoplasias/complicações , Neoplasias/tratamento farmacológico , Transplante de Órgãos , Infecções por Pneumocystis/diagnóstico , Infecções por Pneumocystis/tratamento farmacológico , Infecções por Pneumocystis/etiologia , Infecções por Pneumocystis/prevenção & controle , Pneumocystis carinii/efeitos dos fármacos , Pneumocystis carinii/isolamento & purificação , Pneumonia por Pneumocystis/diagnóstico por imagem , Pneumonia por Pneumocystis/epidemiologia , Pneumonia por Pneumocystis/etiologia , Reação em Cadeia da Polimerase/métodos , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Prognóstico , Radiografia , Combinação Trimetoprima e Sulfametoxazol/uso terapêutico , beta-Glucanas/sangueRESUMO
Diagnosis of pneumocystosis usually relies on microscopic demonstration of Pneumocystis jirovecii in respiratory samples. Conventional PCR can detect low levels of P. jirovecii DNA but cannot differentiate active pneumonia from colonization. In this study, we used a new real-time quantitative PCR (qPCR) assay to identify and discriminate these entities. One hundred and sixty-three bronchoalveolar lavage fluids and 115 induced sputa were prospectively obtained from 238 consecutive immunocompromised patients presenting signs of pneumonia. Each patient was classified as having a high or a low probability of P. jirovecii pneumonia according to clinical and radiological presentation. Samples were processed by microscopy and by a qPCR assay amplifying the P. jirovecii mitochondrial large-subunit rRNA gene; qPCR results were expressed as trophic form equivalents (TFEq)/mL by reference to a standard curve obtained from numbered suspensions of trophic forms. From 21 samples obtained from 16 patients with a high probability of P. jirovecii pneumonia, 21 were positive by qPCR whereas only 16 were positive by microscopy. Fungal load ranged from 134 to 1.73 × 10(6) TFEq/mL. Among 257 specimens sampled from 222 patients with a low probability of P. jirovecii pneumonia, 222 were negative by both techniques but 35 were positive by qPCR (0.1-1840 TFEq/mL), suggesting P. jirovecii colonization. Two cut-off values of 120 and 1900 TFEq/mL were proposed to discriminate active pneumonia from colonization, with a grey zone between them. In conclusion, this qPCR assay discriminates active pneumonia from colonization. This is particularly relevant for patient management, especially in non-human immunodeficiency virus (HIV)-infected immunocompromised patients, who often present low-burden P. jirovecii infections that are not diagnosed microscopically.
Assuntos
DNA Fúngico/genética , Hospedeiro Imunocomprometido , Pneumocystis carinii/genética , Pneumonia por Pneumocystis/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecções Assintomáticas , Líquido da Lavagem Broncoalveolar/microbiologia , Broncoscopia , Criança , Feminino , Imunofluorescência , Genes de RNAr , HIV/patogenicidade , Infecções por HIV/complicações , Infecções por HIV/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Pneumocystis carinii/patogenicidade , Pneumonia por Pneumocystis/complicações , Pneumonia por Pneumocystis/microbiologia , Sensibilidade e Especificidade , Escarro/microbiologia , Adulto JovemAssuntos
Parasitemia/diagnóstico , Reação em Cadeia da Polimerase/métodos , Toxoplasma/genética , Toxoplasmose/diagnóstico , Adulto , Alcoolismo/complicações , Anticorpos Antiprotozoários/sangue , Neoplasias Brônquicas/tratamento farmacológico , Neoplasias Brônquicas/radioterapia , Líquido da Lavagem Broncoalveolar/parasitologia , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Sistemas Computacionais , DNA de Protozoário/sangue , DNA de Protozoário/líquido cefalorraquidiano , Diabetes Mellitus Tipo 1/complicações , Enterobacter cloacae , Infecções por Enterobacteriaceae/complicações , Soronegatividade para HIV , Humanos , Hospedeiro Imunocomprometido , Masculino , Parasitemia/imunologia , Parasitemia/parasitologia , Pneumonia Bacteriana/complicações , Toxoplasma/imunologia , Toxoplasma/isolamento & purificação , Toxoplasmose/sangue , Toxoplasmose/imunologia , Toxoplasmose/parasitologia , Toxoplasmose Cerebral/líquido cefalorraquidiano , Toxoplasmose Cerebral/diagnóstico , Toxoplasmose Cerebral/imunologia , Toxoplasmose Cerebral/parasitologia , Tuberculose Pulmonar/complicaçõesRESUMO
In order to determine the possible relationship between environmental contamination by Aspergillus fumigatus and occurrence of invasive aspergillosis, a one-year prospective study was carried out in the haematology ward of Hautepierre Hospital, Strasbourg, France. During the study period, 21 environmental isolates and 26 clinical isolates of A. fumigatus were collected. Each was genotyped using a random amplification of polymorphic DNA (RAPD) technique. Thirty-four distinct profiles were identified by RAPD analysis, indicating the great genetic diversity of A. fumigatus isolated from infected patients and from the environment. For two patients, RAPD analysis demonstrated concurrent infection by at least two different strains. In two cases, a genetic similarity was noted between isolates obtained from a patient and from the environment.