Chromosome aberrations and sister chromatid exchanges (SCEs) in peripheral blood lymphocyte cultures of untreated leprosy patients

Abstract

Summary The frequencies of various chromsome aberrations and sister chroma tid exchanges (SCEs) were studied in blood lymphocyte cultures of untreated leprosy patients. The frequency of chromosome aberrations was significantly higher in lepromatous (P <O'OOI) and tuberculoid (P < 0'02) groups in compari son with that of controls. The frequency of SCEs was found to be within normal range in the tuberculoid group whereas in lepromatous group, a significant (P < 0·00 I) increase was observed. The findings indicate a probable correlation between the form of leprosy and chromosome damage.A variety of physical and chemical agents as welI as living organisms like viruses are known to cause chromosome aberrations,!-4 and also to induce SCEs.5-7 There is however, very little information on the relationship between bacterial infections and chromosomal aberrations. In spite of the world wide incidence of leprosy, which is a chronic bacterial disease caused by My cobacterium /eprae, there is as yet no report of its effects on the genome of the patient. The in vitro and in vivo studies of the effect of antileprosy drug(s) that have been carried out,S-1O have not ruled out the role of M. /eprae as an additional clastogenic agent. The present study has, therefore, been designed to assess the effects of M. /eprae in causing chromosomal damage in lymphocyte cultures of untreated leprosy patients. Further, the frequencies ofSCEs and chromosome aberrations in different types of leprosy have also been studied.In our heterogeneous lymphocyte cultures, we have utilized just sufficient concentration of 5-Bromodeoxyuridine (BrdU 5 J.lgjml), needed to make sister chromatid differention observable!! as it is extremely important in chromosome mutation studies to use the minimal concentration of the thymidine analogue so that the level of SCEs is kept at its minimum.!2 Both groups consisted of 10 patients each, the paucibacillary group offour fe males and six males (age range 12-55 years), and the multibacillary group of one fe male and nine males (age range 32-65 years). These patients had been carefully selected after ascertaining that they had never undergone treatment for leprosy and apparently had no other disease. Ten age-and-sex-matched normal individuals served as controls. These individuals had had no medication and had not suffered from any viral infections in the immediate 3 months prior to this investigation. LYMPHOCYTE CULTURESPeripheral blood lymphocyte cultures were set up according to the method of Arakaki and Sparkes, 14 with slight modifications. Heparinized whole blood (0' 3 ml) was added to 5 ml of culture medium (TC 199, GIBCO, USA) supplemented with 20% heat inactivated human AB serum, phytohemagglutinin (PHA: DIFCO M) and antibiotics (penicillin and streptomycin). 5-Bromo deoxyuridine (BrdU, Sigma, USA) was added at the final concentration of 5 j1g/ml at the time of culture initiation and the cultures were grown at 3rC for 48 h and 72 h for analysis of aberrations and SCEs respectively. The cultures were protected fr...

Cytogenetic Study for the Effect of Exotoxin a in Mice Caused by Pseudomonas Aeruginosa Isolated from Mastitic Cow

“…Although Gopal et al (1999), who suggested that endo/ exotoxin released by Mycobacterium tuberculosis act as chemical mutagens in generating CA in affected individual. Other similar infections caused by Mycobacterium Lepra [30] and number of viruses, including A and B hepatitis [31] were demonstrated to cause different CAs in human lymphocytes. These abnormalities may involve the autosomes, sex chromosomes, or both.…”

Cytogenetic studies in leprosy patients before and after chemotherapy

“…These studies have not ruled out the possible role of M. leprae as an additional clastogenic agent. Recently we have shown, for the first time, a significant * Present address and address for offprint requests': Patna Women's College, Bailey Road, Patna-800 001, Bihar, India genotoxic effect of this bacterium in terms of the induced frequency of chromosome aberrations and SCEs in untreated leprosy patients, an effect shown to depend on the form of leprosy (D'Souza and Thomas 1988).…”