Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 10 3 2011 09 15 189 194 EN Tahereh Mousavi Department of Immunology, Tehran University of Medical Sciences, Tehran, Iran AND Microbial Resistance Research Center, Tehran University of Medical Sciences, Tehran, Iran AND Immunology Research Center, Tehran University of Medical Sciences, Tehran, Iran Parisa Farnia Mycobacteriology Research Center (NRITLD), Massih Daneshvary Hospital, Tehran, Iran Nader Tajik Department of Immunology, Tehran University of Medical Sciences, Tehran, Iran AND Immunology Research Center, Tehran University of Medical Sciences, Tehran, Iran Mahbubeh Soofi Department of Microbiology, Ghom University of Medical Sciences, Ghom, Iran Farhad shahsavar Department of Immunology, Lorestan University of Medical Sciences, Khorram Abad, Iran 2015 10 01 Analysis of  receptor–ligand  interactions  in  the  context  of  diseases  necessitates  to understand how HLA–KIR genotypes function in diseases. Although CD56+  lymphocytes are derived from multiple lineages, they share a functional association with immunosurviellance and antimicrobial responses. The present study aimed to determine whether KIR phenotype in CD56 lymphocytes and corresponding  HLA-class 1 ligands are associated with multidrug resistance tuberculosis (MDR-TB). We compared the frequencies of HLA-C and HLA-BW4 genes, the expression of KIRs 2DL1/2DS1, 2DL2/2DL3, 3DL1, and 2DS4 and the combinations of HLA/KIR in 32 Nifamycin and Isoniazid-resistant TB with those in 68 drug non resistant (NR) sputum smear positive pulmonary TB patients. PCR-SSP and flow cytometry were performed for HLA and KIRs typing, respectively. We showed no significant differences between inhibitory or activating KIRs as well as HLA ligands in MDR TB patients compared with NR-TB . The combinations of inhibitory KIR-HLA ligands in MDR-TB were much more prevalent, but not statistically significant than in NR patients (p=0.07). The frequency of MDR patients with all HLA-C and HLA- BW4 ligands was higher  than  NR-TB  (p<0.009). Conversely, the  percentage  of  MDR patients having only one kind of HLA gene was significantly lower than NR-TB (p<0.01). We conclude that the expression of inhibitory KIRs with corresponding HLA ligands genes, and/or co-existence of three HLA class 1 ligands for inhibitory KIRs may be associated with drug resistance in pulmonary tuberculosis. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/310 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/310/310