1Department of Virology, Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh.
2Experimental Medicine & Biotechnology, Post Graduate Institute of Medical Education and Research, Chandigarh.
Abstracts of Research Papers Presented during the National Symposium of Indian Virological Society at Unit of Plant Virology, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi-110 012, October 14–1.
Human Cytomegalovirus (HCMV) is a major cause of morbidity and mortality in solid organ transplants and immunocompromised patients i.e. AIDS. Around 80% of renal transplant recipients get infected with cytomegalovirus where as only 10–20% of them develop CMV disease. A number of diagnostic modalities like shell vial culture, antigenemia, serology and PCR are used to detect HCMV. Studies have shown correlation of antigen load in terms of CMV pp65 antigen positivity with progression of disease. Thus, the study was planned to compare antigenemia, PCR and IgM as diagnostic tool for the detection of CMV disease and to study the correlation of antigen load and genotype with clinical severity of CMV disease in renal transplant recipients.
Blood samples were collected from 30 renal transplant recipients at 2, 4, 8 & 12 weeks post transplant (group I) & 28 renal transplant recipeints who had clinically suspected CMV disease (groupII). All the patients of group II were graded as mild, moderate & severe according to presence of one, more than one of previously specified symptoms and multi-organs involvement respectively. CMV pp65 antigenemia was done by using specific monoclonal antibody by indirect immunofluorescence (1.5 x 105 cells/smear), CMV IgM by μ - captue ELISA and nested PCR for immediate early genes. 11 samples (7 of group I and 4 of group II) samples were subjected for genotyping study. Genotyping was carried out by nested PCR for CMV gB gene followed by digestion with Rsa I restriction enzyme.
Out of 30 patients in group I, 22 were positive for pp65 antigenemia, 24 for PCR and none for CMV IgM. Eight were positive for CMV pp65 antigenemia by 8 weeks post transplantation and 14 by 12 week post transplantation. Of them, 2 developed disease and both had antigen positive cells above 40/1.5 x 105 cells. Of the 28 patients in group II, 13 for pp65 antigenemia, 22 for PCR, and 3 for CMV IgM antibody were found positive. The numebr of pp65 antigen positive cells in 9 patients of mild disease were 5–24 cells per smear, in 1 patient of moderate disease had 26–45 and in 3 patients of severe disease had >100/smear. Amongst 11 samples studied, 3 different genotypic patterns (A, B & C) were seen. Five of 7 patients of group I had genotype A, 1 and B and 1 had C. 4 patients belonged to group II of which genotype A was found in 2, genotype B in 2. 66.6% (20/30) renal transplant recipients from Group I had asymptomatic CMV infection with in 12 weeks of post transplantation. The chances of development of CMV disease is more in patients with > 40 pp65 positive cells per smear. Genotype A was found to be more common in renal transplant recipients.
