title: On the long-term effects of methyl isocyanate on cell-mediated immunity in Bhopal gas-exposed long-term survivors and their offspring.
abstract: Methyl isocyanate (MIC) is a toxic industrial chemical that is documented as a potent respiratory toxicant. We investigated cell-mediated immunity (CMI) in the MIC-exposed long-term survivors and their offspring born after the Bhopal gas-leak tragedy in 1984. Several earlier reports show inconsistency in the assessment of immunological effects of MIC on the human population. In these studies, important factors including lifestyle attributes were overlooked. We incorporated these factors also in our study of the basic cell-mediated immune function in the Bhopal MIC-affected population. Twenty-seven years after exposure, we assessed the circulating T-lymphocyte frequency using E-Rosette assay. A total of 46 MIC-exposed healthy long-term survivors and their offspring were studied vis-a-vis parallel gender-age group-matched unexposed controls from Bhopal and various other regions of India. The influence of several lifestyle variabilities (smoking, alcohol intake, and tobacco chewing) on T-lymphocyte frequency was also taken into consideration. Our observations suggest that Erythrocyte-Rosette-forming cell (E-RFC) distribution frequency is largely insignificant in the MIC-affected population as compared to controls ( p > 0.05). In the MIC-affected tobacco chewers, there was a trend of suppression in CMI (relative decrease = 10.3%) as compared to nonchewers. Overall, our results show negligible long-term effect of MIC on CMI measured in terms of E-RFC frequency. These observations are not in agreement with earlier findings that immunosuppressive effects of MIC exposure persist in the T-cells of the affected population. However, atypical lymphocytes were frequently observed as E-RFC in the exposed females when compared to all other subgroups. Hematopoietic disorders (atypical lymphocytosis) in the MIC-affected population along with previous reports on the cytogenetic and humoral immune system linking cancer risk and chronic obstructive pulmonary disease (COPD) are important.
authors.affiliation: 1 Department of Research, Clinical Cytogenetics Laboratory, Jawaharlal Nehru Cancer Hospital & Research Centre (JNCHRC), Bhopal, Madhya Pradesh, India.|2 Rajiv Gandhi Technological University (RGTU), Bhopal, Madhya Pradesh, India.
authors.forename: Chinnu Sugavanam
authors.initials: CS
authors.lastname: Senthilkumar
authors.affiliation: 3 Department of Life Sciences (Botany), TNB College, TM Bhagalpur University, Bhagalpur, Bihar, India.
authors.forename: Nand Kishore
authors.initials: NK
authors.lastname: Sah
authors.affiliation: 1 Department of Research, Clinical Cytogenetics Laboratory, Jawaharlal Nehru Cancer Hospital & Research Centre (JNCHRC), Bhopal, Madhya Pradesh, India.
authors.forename: Narayanan
authors.initials: N
authors.lastname: Ganesh
mesh_terms: D000293:Adolescent; D000328:Adult; D055908:Bhopal Accidental Release; D015415:Biomarkers / Q000097:blood; D002648:Child; D005260:Female; D005739:Gas Poisoning / Q000097:blood / Q000276:immunology* / Q000503:physiopathology; D006801:Humans; D007111:Immunity, Cellular / Q000187:drug effects*; D007166:Immunosuppressive Agents / Q000633:toxicity*; D007194:India / Q000453:epidemiology; D019570:Inhalation Exposure / Q000009:adverse effects; D017953:Isocyanates / Q000633:toxicity*; D008218:Lymphocytosis / Q000209:etiology*; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects; D008875:Middle Aged; D009369:Neoplasms / Q000139:chemically induced / Q000453:epidemiology / Q000276:immunology; D018812:Paternal Exposure / Q000009:adverse effects; D010575:Pesticides / Q000633:toxicity*; D029424:Pulmonary Disease, Chronic Obstructive / Q000139:chemically induced / Q000453:epidemiology / Q000276:immunology; D012306:Risk; D012737:Sex Factors; D017741:Survivors; D055815:Young Adult
chemical_list: D015415:Biomarkers; D007166:Immunosuppressive Agents; D017953:Isocyanates; D010575:Pesticides; C008461:methyl isocyanate
keywords: Bhopal; E-Rosettes; India; T-lymphocyte frequency; cell-mediated immunity; immunotoxic effects; long-term survivors and offspring; methyl isocyanate exposure