Reply to Letter to Editor regarding the article, "Idiopathic CD4+ T lymphocytopenia: A case report".

We thank the authors for their comments on our recently published case report.1In this case study, the patient had no other complications apart from toxic megacolon condition, which was diagnosed as ulcerative colitis with pancolitis of grade IV activity. The details of investigations including blood and biochemical parameters have already been stated in the article.1The CD4 count of the patient was found to be less (296/mm3) than normal range and hence, the patient was assessed for other infections, primarily the human immunodeficiency virus (HIV), which is the main cause for the depletion of CD4 count. The patient did not had any HIV-associated risk factors including multiple sex partners, unprotected sex, intravenous drug abuse, or blood transfusion/transplant. Also, he had no history of surgery or hospitalization. However, to rule out the possibility of HIV, rapid diagnostic tests (RDT) were done at Integrated Counselling and Testing Center (ICTC). Later, the advanced fourth generation Abbott Architect HIV Ag/Ab Combo Assay (CLIA moderate) was employed to detect p24 antigen and antibodies to HIV-1 and HIV-2 at very early infection. Since, the CD4 count declined from 296/mm3 to 56/mm3 in a gap of 3 months, the HIV tests were repeatedly carried out. Notably, the HIV infection was found to be negative, prior and after the surgery. Moreover, to exclude the false negative results, and to confirm the HIV infection, RDT and CLIA were repeated. The well-established and widely accepted testing strategies and supplies used in the study are approved by National AIDS Control Organization (NACO)/FDA. The HIV tests were carried out in the National Accreditation Board for Testing and Calibration Laboratories (NABL, India) accredited laboratory, which maintains high standards of quality. Next, the results were analyzed and interpreted by well-trained microbiologists, who manage the laboratory conforming to all standards. Thus, user errors are almost nil. In the context of toxic megacolon, it is the most common complication of ulcerative colitis[2] and was confirmed by histopathological analysis of the resected colonic specimen. The patient was conservatively treated with immunosuppressant steroids (hydrocortisone; 100 mg) for a short course of three days, prior to surgery but the patient did not respond. In this case, the patient exhibited lymphopenic conditions for more than three months; therefore, the possibilities of transient lymphopenia conditions are unusual. Noteworthy, the viral infections and immune stimulations accompany lymphopenia, which are primarily involved in type 1 interferon-mediated lymphocyte activation.[3] However, interferon assay was not carried out in the present case.

Conflicts of interest

There are no conflicts of interest.