Immunocytochemical detection of Mycobacterium Tuberculosis complex specific antigen, MPT64, improves diagnosis of tuberculous lymphadenitis and tuberculous pleuritis.

BACKGROUND: A rapid, sensitive and accurate laboratory diagnosis is of prime importance in suspected extrapulmonary tuberculosis (EPTB) cases. However, traditional techniques for the detection of acid-fast bacilli have limitations. The aim of the study was to evaluate the diagnostic value of immunocytochemical staining for detection of Mycobacterium tuberculosis complex specific antigen, MPT64, in aspirates from pleural effusions and lymph nodes, the most common presentations of EPTB. METHOD: A cross-sectional study was conducted by including patients at Tikur Anbessa Specialized Hospital and the United Vision Medical Services from December 2011 to June 2012. Lymph node aspirates and pleural fluid samples were collected and analyzed from a total of 51 cases (26 tuberculous (TB) pleuritis and 25 TB lymphadenitis) and 67 non-TB controls. Each specimen was subjected to Ziehl-Neelsen (ZN) staining, culture on Lowenstein- Jensen (LJ) medium, cytological examination, Polymerase Chain Reaction (PCR) using IS1081gene sequence as a primer and immunocytochemistry (ICC) with polyclonal anti-MPT64 antibody. All patients were screened for HIV. RESULT: ICC was positive in 38 of 51 cases and in the 7 of 67 controls giving an overall sensitivity and specificity of 74.5% and 89.5%, respectively. Using IS1081-PCR as a reference method, the sensitivity and specificity, positive and negative predictive value of ICC was 88.1%, 89.5%, 82.2% and 93.2%, respectively. The case detection rate increased from 13.7% by ZN stain to 19.6% by LJ culture, to 66.7% by cytology and 74.5% by ICC. CONCLUSION: Immunocytochemistry with anti-MPT64 antigen improved detection of TB in pleural effusion and lymph node aspirates. Further studies using monoclonal antibodies on samples from other sites of EPTB is recommended to validate this relatively simple diagnostic method for EPTB.

Magnitude of cytopenias among HIV-infected children in Bahir Dar, northwest Ethiopia: a comparison of HAART-naïve and HAART-experienced children.

BACKGROUND: AIDS, caused by HIV, is a multisystem disease that affects hematopoiesis. The aim of this study was to assess cytopenias among HIV-infected children who had a follow-up at Felege Hiwot Referral Hospital, Bahir Dar, northwest Ethiopia. METHODS: An institution-based cross-sectional study was conducted between April and May 2013. Systematic random sampling method was used to select the study participants. Descriptive statistics, independent t-test as well as chi-square and logistic regression were used for analysis. A p-value <0.05 was considered as statistically significant. RESULTS: A total of 224 children (112 highly active antiretroviral therapy [HAART]-naïve and 112 HAART-experienced) participated in the study. The magnitude of anemia, thrombocytopenia, neutropenia, leukopenia and pancytopenia among HAART-naïve HIV-infected children were 30.4%, 9.8%, 8%, 4.5% and 1.8%, respectively. The overall prevalence of anemia, neutropenia, thrombocytopenia, leukopenia and pancytopenia were 29.5%, 8.9%, 8%, 4.5% and 1.4%, respectively. Cluster of differentiation-4 percentage and mean corpuscular volume were significantly different between HAART-experienced and HAART-naïve children. Being of younger age and severely immunosuppressed were risk factors of anemia. CONCLUSION: Anemia was the most common cytopenia, followed by neutropenia. Severe immunosuppression and younger age were significantly associated with anemia. Therefore, emphasis should be given for investigation and management of cytopenias in HIV-infected children, particularly for those who are immunosuppressed and of younger age.