Mannose binding lectin gene variants and susceptibility to tuberculosis in HIV-1 infected patients of South India

Mannose binding lectin (MBL) plays an important role in innate immunity. Plasma MBL levels and MBL2 gene polymorphisms were studied in HIV-1 infected patients without tuberculosis (HIV+TB-) (n = 151) and with tuberculosis (HIV+TB+) (n = 109), HIV negative tuberculosis patients (HIV-TB+) (n = 148) and healthy controls (n = 146) by ELISA and genotyping by polymerase chain reaction based methods. MBL Levels were significantly increased among HIV-TB+ and HIV+TB+ patients than controls and HIV+TB- patients (P < 0.05). A significantly increased frequency of 00 genotype of structural polymorphism and YY genotype of -221Y/X was observed among HIV-TB+ patients than controls. In HIV+TB+ patients, a significantly increased frequency of YA/YA diplotype (associated with very high MBL levels) was observed compared to controls (P = 0.03). In HIV+TB+ patients, a significantly decreased frequency of medium MBL expression diplotypes (XA/XA and YA/YO) were noticed compared to HIV+TB- and healthy controls. The results suggest that YA/YA diplotype associated with very high MBL Levels may predispose HIV-infected patients to tuberculosis while O/O genotype associated with very tow MBL levels may be associated with susceptibility to tuberculosis in HIV uninfected individuals. Medium MBL expression diplotypes might protect against development of TB in HIV-infected patients. (c) 2007 Elsevier Ltd. All rights reserved.