Western blot pattern in HIV positive individuals in Namakkal, South India.

摘要

Objective: The objective of this study was to determine the western blot pattern among HIV positive individuals in different stages of HIV infection in Namakkal, South India. Material and methods: After an informed consent, Western Blot test from 40 HIV seropositive patients attending the ART center at Namakkal, were performed using HIVBLOT 2.2, manufactured by Genelabs diagnostics, Singapore, as per the kit instructions. Demographic, clinical and diagnostic data were collected. Results: The age ranged from 22-51 years (mean- 36 years). 47.5% were males and 52.5% were females. The patients were classified according to the WHO stages. Eleven patients were in Stage I, 10 each in Stage II and III and 9 patients were in Stage IV. With the exception of p24, the other GAG proteins, p55, p39 and p17 are not expressed very efficiently in Stage I patients. The expression of gp160, gp41, p66, p31 have all increased by approximately 10-20% in Stage II. In stage III, the ENV proteins gp160 and gp120 have been found in 90% of the cases. There was a 20% decrease in the incidence of p24 protein. Of the nine stage IV samples, 89% conform to the WHO interpretation criteria. Conclusion: Interpretation of the WB band pattern in combination with clinical features may be occasionally useful in predicting the stage of HIV infection. This study suggests that antibodies to gag antigen P17 may be used as a marker for disease progression. Background At present, the enzyme linked immuno sorbet assay (ELISA) is the most widely used serological test for the detection of antibodies to HIV 1, 2. For diagnosis of clinically suspected cases and for voluntary testing, testing is performed with ERS (ELISA/Rapid/Simple) using HIV kits with different antigens in the government settings.3 Western blot assay is often regarded as the gold standard for confirmation of HIV serostatus. Although the overall sensitivity and specificity of the WB for detection of antibodies to the various viral proteins is high, there have been substantial differences in the timing of the appearance of antibody bands and their intensities during different stages of HIV infection4. The objective of this study was to determine the western blot pattern among HIV positive individuals in different stages of HIV infection in Namakkal, South India. Material and methods After obtaining informed consent, blood was collected from 40 known HIV seropositive patients attending the ART center at Namakkal. 2ml of whole blood was collected in EDTA vaccutainer tube. The serum was separated from the whole blood. The samples were stored and transported in cold chain to the Department of Experimental Medicine and AIDS Research Center at the TN Dr. MGR Medical University in Chennai. They were stored at -20°C till further analysis in the laboratory. Western Blot test was performed using HIVBLOT 2.2, manufactured by Genelabs diagnostics, Singapore. The samples were processed as per the kit instructions. Performa was filled to obtain demographic, clinical and diagnostic data. For the interpretation of the western blot strips, WHO criteria were followed. Results The age of the patients ranged from 22-51 years with a mean of 36 years. 47.5% were males and 52.5% were females. Average income of the patients were Rs.. 1660/month ($40/month). Majority (47.5%) were daily wage workers or otherwise called coolies The patients were classified according to the WHO stages. Eleven patients were in Stage I, 10 each in Stage II and III and 9 patients were in Stage IV (figure 1).