Anti-IFN-γ autoantibodies underlie disseminated Talaromyces marneffei infections.

Talaromyces marneffei causes life-threatening opportunistic infections, mainly in Southeast Asia and South China. T. marneffei mainly infects patients with human immunodeficiency virus (HIV) but also infects individuals without known immunosuppression. Here we investigated the involvement of anti-IFN-γ autoantibodies in severe T. marneffei infections in HIV-negative patients. We enrolled 58 HIV-negative adults with severe T. marneffei infections who were otherwise healthy. We found a high prevalence of neutralizing anti-IFN-γ autoantibodies (94.8%) in this cohort. The presence of anti-IFN-γ autoantibodies was strongly associated with HLA-DRB1*16:02 and -DQB1*05:02 alleles in these patients. We demonstrated that adult-onset acquired immunodeficiency due to autoantibodies against IFN-γ is the major cause of severe T. marneffei infections in HIV-negative patients in regions where this fungus is endemic. The high prevalence of anti-IFN-γ autoantibody-associated HLA class II DRB1*16:02 and DQB1*05:02 alleles may account for severe T. marneffei infections in Southeast Asia. Our findings clarify the pathogenesis of T. marneffei infection and pave the way for developing novel treatments.

[Clinicopathologic correlation between CD4-positive T lymphocyte counts and superficial lymphadenopathy in HIV-positive/AIDS patients].

OBJECTIVE: To explore the clinicopathological correlation between CD4(+) T lymphocyte count and superficial lymphadenopathy HIV/AIDS patients. METHODS: A total of 1066 HIV/AIDS patients were included in this study. The incidence of superficial lymphadenopathy, peripheral blood CD4(+) T lymphocyte counts and histological features of superficial lymphadenopathy were analyzed. RESULTS: Among 1066 patients, 126 cases (11.8%) presented with superficial lymphadenopathy. Of the 126 cases, there were 69 cases with CD4(+) T lymphocyte counts < 100/µl and clinical diagnoses including tuberculosis (37 cases), reactive hyperplasia (8 cases), AIDS-related lymphadenopathy (18 cases), penicillium diseases (12 cases), fungal infection (5 cases) and non-tuberculous mycobacterial infection (1 case). Twenty-six cases had CD4(+) T lymphocyte counts between 100/µl to 200/µl and clinical diagnosis including tuberculosis (12 cases), reactive hyperplasia (8 cases), AIDS-related lymphadenopathy(6 cases), penicillium disease (2 cases) and non-Hodgkin lymphoma (1 case). Twenty-nine cases had CD4(+) T lymphocyte counts > 200/µl and clinical diagnoses including tuberculosis (11 cases), reactive hyperplasia (12 cases), AIDS-related lymphadenopathy (3 cases), Penicillium diseases (1 case) and non-Hodgkin lymphoma (4 cases). The CD4(+) T lymphocyte counts among patients with tuberculosis, AIDS-related lymphadenopathy and Penicillium diseases were significantly different (χ(2) = 8.861, P = 0.012). A significant correlation between the incidence of superficial lymphadenopathy and CD4(+) T lymphocyte counts was found (χ(2) = 375.41, P = 0.000). CONCLUSIONS: The most common cause of superficial lymphadenopathy in HIV/AIDS patients is tuberculosis, followed by lymph node reactive hyperplasia, AIDS-related lymphadenopathy and Penicillium disease. Low CD4(+) T lymphocyte count correlates with an increased incidence of superficial lymphadenopathy and the risk of opportunity infection. Therefore, determination of peripheral blood CD4(+) T lymphocyte count should become an integral marker for the early diagnosis and treatment of superficial lymphadenopathy in HIV/AIDS patients.

[Identification of Mycobacterium tuberculosis and rifampin-resistant strains by gene-chips].

OBJECTIVE: To evaluate the gene-chip detecting rifaman-resistance Mycobacterium tuberculosis applied in TB diagnosis and drug-resistant detection. METHODS: Mycobacterium tuberculosis and rifaman-resistant strains among 35 rifaman-resistance isolated strains and 102 sputa specimens from TB patients, 27 sputa specimens from other patients were examined the gene-chips. Results obtained were compared with sputum examination, bacteriological culture and standard drug susceptibility test of Mycobacterium tuberculosis. RESULTS: Thirty-five rifaman-resistance strains were detected by gene-chips and 33 were identified as rifaman-resistance strains and the concordance with the traditional drug susceptibility test of Mycobacterium tuberculosis was 94.29%. Twenty-seven sputa specimens from other patients were examined Mycobacterium tuberculosis by the gene-chips, 2 were positive, the detection specialty was 92.59%. Using three methods detecting Mycobacterium tuberculosis among 102 sputa specimens the positive rate respectively was, sputum examination 35.29% (36/102), bacteriological culture 28.43% (29/102), gene-chip 77.45% (79/102). Among 102 sputa specimens only 29 examined Mycobacterium tuberculosis by the traditional drug susceptibility test and 8 were rifaman-resistant strains. While using gene-chip, there were 20 among 102 sputa specimens identified as rifaman-resistance strains. Among total 55 rifaman-resistance strains detected by the gene-chips, the most frequent mutations were those associated with codon 531 (23 of 55; 41.8%), 526 (15 of 55; 27.27%) and 516 (9 of 55; 16.36%). CONCLUSION: Results showed that this was a rapid, simple and highly specific method when using gene-chip to detect Mycobacterium tuberculosis and rifaman-resistant strains.