715. Chandra G, et al. BamH1 polymorphism of Human Cytochrome P450 gene, CYP2D6, in quiescent and relpse patients of pulmonary tuberculosis

BamH l polymorphism of the human cytochrome P450 gene, CYP2D6, which encodes drug metabolizing enzyme, was studied to find out whether variant genotypes of this gene are associated with the susceptibility or resistance to bacteriological relapse of pulmonary tuberculosis after stopping treatment with short-course chemotherapy of 6-8 months duration. The study was carried out in control subjects (n=158), patients with pulmonary tuberculosis (n=154), patients with bacteriological relapse (n=50) and quiescent patients (n=50). No difference in the frequency of variant genotypes of BarnH l polymorphism of CYP2D6 gene was observed between pulmonary TB patients and control subjects. A trend towards an increased frequency of 22 genotype (homozygous for infrequent allele 2) was observed in bacteriological relapse patients than quiescent patients (odds ratio, OR: 2). Similar increase was observed in male relapse patients than male quiescent patients (OR: 2.2). The present study suggests that 22 genotype of BamH l polymorphism of CYP2D6 of human cytochrome P450 gene either alone or in combination with closely linked genes may be associated with bacteriological relapse especially in male patients of pulmonary tuberculosis

Rare Chimaeroid and Elasmobranch fishes from the continental slope off the West Coast of India

During exploratory trawling from the upper continental slope in depths between 180 and 450 metres off the West Coast of India, specimens of the Chimreroid fish Neoharriotta pinnata (Schnackenbeck) and the rare elasmobranchs Echinorhinus b"UC11S (Bonnaterrc) and Atractophorus armatus Gilchrist have been obtained. All three are new distributional records for Indian Seas and they are described and illustrate

Non-HLA gene polymorphism in pulmonary tuberculosis

BCG vaccination has been shown to give protection against tuberculosis. However, South Indian (Chingleput) Trial of BCG vaccination did not give any protection against bacillary forms of tuberculosis. A number of hypotheses and possibilities were put forward for this failure (1). One of the possibilities suggested was the genetics of the people (Host genetics) living in that region. Pulmonary tuberculosis is a granulomatous lung disease caused by Mycobactrium tuberculosis. Susceptibility to tuberculosis has been suggested to be multifactorial. Though environmental and socio-economic factors are primarily related, numerous studies have emphasised the importance of host resistance and hereditary susceptibility (2,3)

HLA-DR2 subtypes & immune responses in pulmonary tuberculosis

Background & objectives: HLA-DR2 has been shown to be associated with the susceptibility to pulmonary tuberculosis and altered antibody and lymphocyte response in pulmonary tuberculosis. In the present study, the influence of DR2 subtypes on antibody titre and lymphocyte response ,to Mycobacterium tuberculosis culture filtrate antigens (10 μg/ml) was studied in 22 patients with active pulmonary TB (ATB), 50 inactive (cured) TB (ITB) patients and 36 healthy control subjects. Methods. HLA-DR2 gene was amplified by polymerase chain reaction (PCR) and dot-blotted. Genotyping of DRBl*1501, *1502, *1503, *1601 and *1602 was carried out using sequence specific oligonucleotide probes (SSOPs) and detected by chemiluminescence method. Antibody titre as well as lymphocyte response to M.tuberculosis antigens were measured by enzyme linked immunosorbent assay (ELISA) and lymphocyte transformation test (LTT) respectively. Results: The allele frequency of DRB1*15Ol was significantly increased in pulmonary tuberculosis patients as compared to controls (P<0.05). No marked difference in the antibody titre and lymphocyte response to M. tuberculosis antigens was observed between the DRBl *1501, *1502 and *1503 positive or negative controls, ATB and ITB patients. DRBl *1501 and *1502 positive as well as negative ATB patients showed a higher antibody titre as compared to controls and ITB patients. ITB patients with *1502 showed a higher lymphocyte response as compared to *1502 positive controls (P<0.001) and ATB patients (P<0.05). Similarly, an increased lymphocyte response was observed in *1501, and *I503 negative ITB patients compared to *1501 and *1503 negative controls and ATB patients. Interpretation & conclusion: The present study revealed that DRBl *1501 may be associated either alone or with other DR2 alleles, with the susceptibility to pulmonary tuberculosis. None of the DR2 alleles influenced the antibody and lymphocyte response to M tuberculosis culture filtrate antigens. This suggested that HLA-DR2 gene/gene products as a whole may influence the immune response in pulmonary tuberculosis

Influence of non-MHC genes on lymphocyte response to Mycobacterium tuberculosis antigens and tuberculin status in Pulmonary tuberculosis

Background & objectives : Major histocompatibility complex (MHC) genes are known to influence the immune functions. In the present study, the influence of non-MHC genes such as mannose binding protein (MBP), vitamin D receptor (VDR) and interleukin-1 receptor antagonist (IL-IRA) gene polymorphisms on lymphocyte response to Mycobacterium tuberculosis culture filtrate antigen (10 μg/ml) was studied in 44 patients with active pulmonary TB and the family contacts (35) and in 32 normal healthy subjects. The influence of these gene polymorphisms on tuberculin (1TU of PPD of M. tuberculosis) reactivity status in 146 pulmonary TB patients was also studied. Methods : The MBP and VDR genes were amplified using polymerase chain reaction (PCR) and genotyping was carried out using sequence specific oligonucleotide probes by dot blot and IL-1RA by agarose gel electrophoresis. Results : A significantly decreased lymphocyte response to M. tuberculosis antigen was seen in pulmonary TB patients positive for functional mutant homozygotes of MBP (00) compared to heterozygote carriers (AO; P<0.02) and wild homozygotes (AA; P<0.01). The variant mutant genotype (tt) of VDR gene was associated with an increased lymphocyte response in control subjects compared to active TB patients with tt genotype (P<0.05). Heterozygote carriers of MBP (AO) were associated with a significantly (P<0.001) decreased tuberculin reactivity compared to wild homozygotes (AA). The VDR genotype Tt (heterozygote carrier) was associated with an increased tuberculin reactivity in female TB patients as compared to male patients (P<0.001). Interpretation & conclusions : The present study suggested that MBP and VDR genes influence the cell mediated immune response in pulmonary TB patients. Non-MHC genes along with HLA-Class II genes/gene products may be playing an immunoregulatory role in the mechanism of susceptibility/resistance to tuberculosis

Vitamin D receptor and interleukin-1 receptor antagonist gene polymorphism in spinal tuberculosis

Our earlier studies revealed that both MHC (Major Histocomptibility Complex) and non-MHC genes are associated with the susceptibility to pulmonary tuberculosis (TB). To find out whether non-MHC genes such as vitamin D receptor (VDR) and interleukin-1 receptor antagonist (IL-1RA) genes are associated with the susceptibility to spinal TB (extrapulmonary form of TB), the present study was carried out in spinal TB patients (n=66) and spouses of TB patients (spinal-TB and pulmonary-TB) ( n = 80) (family contacts). A trend towards an increased per cent genotype frequency of IL-1RA genotype variant 22 (12.1%) was seen in spinal TB patients when compared to the controls (3.8%) (spouses of the patients) (P=0.057; odds ratio 3.5). No difference was observed in the frequency of VDR genotypes between the overall spinal TB patients and the family contacts. However, the VDR mutant genotype tt was seen at a higher frequency in female patients with TB spine (TBS) (12.8%) than female contacts (4.2%) ( P >0.05 not significant; odds ratio 3.5). Among the contacts, a significantly increased frequency of wild type genotype TT (wild homozygotes) was seen in female contacts (55.1%) than male contacts (16.1%) (P =0.0012). Similarly a significant decrease in tt genotype was seen in female contacts (4.1%) than male contacts (25.8%) (P=0.012). The present study suggests that IL-1RA genotype 22 may be associated with the susceptibility to spinal TB. Moreover, vitamin D receptor tt genotype may be associated with the susceptibility to spinal TB in female patients. The study reveals that multicandidate genes may be associated with the susceptibility to spinal TB

HLA-DR phenotypes and lymphocyte response to M. tuberculosis antigens and in cured spinal tuberculosis patients and their contacts

Background: Our earlier studies on Human Leucocyte Antigens (HLA) in pulmonary tuberculosis patients revealed the association of HLA-DR2 antigen with susceptibility to pulmonary TB and DR2 antigen has been shown to influence the immunity to tuberculosis. Objectives: The present study was carried out to find out whether HLA-DR antigens are associated with susceptibility to spinal tuberculosis. Moreover, the role of HLA-DR antigens on lymphoproliferative response to Mycobacterium tuberculosis culture filtrate antigens was studied using Lymphocyte Transformation Test (LTT). Material and Methods: HLA-DR genotyping and lymphoproliferative response was carried out in 63 cured spinal TB patients and 63 control subjects (spouses of pulmonary and spinal TB patients). Results: A trend towards an increased frequency of HLA-DR9 antigen was observed in spinal TB patients compared to controls. A significantly decreased lymphocyte response to M. tuberculosis antigens was observed in HLA-DR9 antigen positive control subjects compared to HLA- DR9 antigen negative subjects (P=0.0009) whereas increased response was observed with DR9 positive cured spinal TB patients compared to HLA-DR9 antigen negative patients. Further, HLADR3 antigen positive patients showed a decreased lymphocyte response compared to HLA-DR3 antigen negative patients (P<0.05). Conclusion: The study suggests that HLA-DR9 antigen either alone or in combination with other HLA antigen as lhplotype and non-HLA genes may be associated with susceptibility to spinal TB and play a regulatory role on the immune response to M. tuberculosis in spinal tuberculosis patients

Lymphocytotoxic antibodies & immunity in pulmonary tuberculosis

To understand whether the presence of cold reactive lymphocytotoxic antibodies (LCA) (reactive at 15°C) in the system has any effect on immunity to tuberculosis lymphocytotoxic antibodies to adherent cells (enriched-B ceils) and non-adherent cells were studied in active-TB (n=42) and inactive-TB (cured) patients (n=49) and healthy controls (n=32). The plasma samples of inactive-TB patients showed higher percentage of positivity for lymphocytotoxic antibodies (36.7%) than the active-TB patients (21.4%) and control subjects (18.8%). No significant difference on antibody and lymphocyte response against Mycobacterium tuberculosis culture filtrate antigens was observed between LCA positive and LCA negative active-TB patients and normal healthy controls. Further, determinationof HLA-DR phenotype of the patients and control subjects showed that individuals positive for lymphocytotoxic antibodies were more among HLA-DR2 positive and DR7 positive active-TB patients and control subjects than non-DR2 and non-DR7 subjects. The present study suggests that the cold reactive lymphocytotoxic antibodies may be against B-lymphocytes and persistent for a longer time. HLA-DR2 and -DR7 may be associated with the occurrence of LCA activity. Further, the presence of LCA has no immunoregulatory role on immunity to tuberculosis

Interleukin-12B & interleukin-10 gene polymorphisms in pulmonary tuberculosis

Background & objectives: Cytokines play an important role in anti-tuberculosis immune response. Skewing of immunity from protective to pathogenic may involve a shift in Th1-Th2 paradigm. Cytokine gene polymorphism is known to be associated with functional differences in cytokine regulation and altered clinical performance in a variety of diseases. The aim of this study was to know whether Interleukin-12B 3’ UTR (Taq1) (A/C) and Interleukin-10 (-1082 G/A) gene polymorphisms were associated with susceptibility to pulmonary tuberculosis. Methods: IL -10 (-1,082 G/A) and IL-12B gene polymorphisms were studied in132 pulmonary TB (PTB) patients and 143 normal healthy subjects (NHS), using DNA based polymerase chain reaction (PCR) with sequence specific primers and restriction digestion. Results: The allelic as well as genotypic frequencies of Interleukin -10 (-1082) and Interleukin -12B (3’UTR Taq 1) did not differ significantly between the patients and controls. Interpretation & conclusion: Our findings suggested that IL -10 (-1082 G/A) and IL -12B 3’UTR (Taq I) (A/C) gene polymorphisms were not associated either with susceptibility or resistance to pulmonary tuberculosis in the south Indian population

Influence of HLA-DR2 phenotype on humoral immunity & lymphocyte response to Mycobacterium tuberculosis culture filtrate antigens in pulmonary tuberculosis

Association of HLA-DR2 genes/gene products has been shown with pulmonary tuberculosis (PTB) patients in India. In the present study, the influence of HLA-DR2 and non-DR2 genes/gene products on immunity to tuberculosis has been studied. Plasma samples of -DR2 positive patients (active and inactive TB) showed a higher antibody titre to Mycobacterium tuberculosis culture filtrate antigens than non-DR2 (-DR2 negative) patients. Immunoblot analysis revealed a trend towards an increased percentage of DR2 positive patients recognizing 38, 32/34 and 30/31 kDa antigens of M. tuberculosis than DR2 negative patients. A low spontaneous lymphoproliferative response (without antigen stimulation) was seen in HLA-DR2 positive active TB patients than HLA-DR2 negative patients. However, the antigen stimulated lymphocyte response was higher in the -DR2 positive patients (active and inactive TB) when compared to non-DR2 patients. Further, an inversional correlation between antibody titre and spontaneous as well as antigen induced lymphocyte response (measured by 3H thymidine uptake and expressed as counts per minute) was seen in HLA-DR2 positive active PTB patients than non-DR2 patients. The present study suggests that HLA-DR2 genes/gene products may be associated with a regulatory role in the mechanism of disease susceptibility to tuberculosis. The genes while augmenting the humoral immune response, they suppress the spontaneous and antigen induced lymphocyte response in -DR2 positive patients with active disease. Key words Antigen recognition - HLA-DR2-antibody titre - lymphocyte response - Mycobacteriu