A study on human leukocyte antigen class I molecules in paediatric bronchial asthma.

Childhood asthma, often associated with atopy, is more common in boys and may persist throughout life in 50% of cases. This case-control study was carried out to examine if any association of paediatric bronchial asthma with human leukocyte antigen (HLA) class I antigens. Thirty-six children with bronchial asthma diagnosed on basis of Global Initiative for Asthma (GINA) criteria and an equal number of healthy controls without history of bronchial asthma were studied. Low resolution HLA- ABC typing was performed by sequence specific primers (SSP) and the frequency of HLA–ABC antigens in the two groups was compared. Total serum immunoglobulin E (IgE) estimation was done as a marker of atopy by ELISA. The study included 24 boys and 12 girls aged 13 months to 11 yrs, of which 16 (44%) had positive family history. Serum IgE levels were elevated in 20 (55%) of the cases and 33% of controls with peak values of 4877 and 627 IU/ml, respectively. No statistically significant correlation was observed between childhood asthma and HLA class I antigens, however, a statistically significant correlation was observed between serum IgE levels and asthma, which was elevated in cases, as compared to normal population. Serum IgE levels did not show a linear trend, in that a direct correlation with the severity of disease was not observed.

Recombination in human leukocyte antigen region in two Asian Indian families.

BACKGROUND: Recombination (crossing over) may generate novel haplotypes that can be beneficial to a population against recently introduced pathogens. It may lead to the generation of new alleles. SETTINGS AND DESIGN: A prospective study at a tertiary care centre. AIM: To report two rare cases of crossing over in HLA region. MATERIALS AND METHODS: Tissue-typing was done by sequence specific primers (SSP) for DR locus and by both SSP and serology for Class I which was reconfirmed on fresh samples. RESULTS: In one patient crossing over had taken place in the region of A locus resulting in inheritance of A*01 instead of expected A*11. In second family crossing over had taken place in region of DRB1 locus and the sibling inherited DRB1*08 instead of DRB1*10. CONCLUSIONS: Possibility of recombination must be considered when interpreting implausible tissue-typing results of families worked up for BMT.

Antiphospholipid antibodies in young myocardial infarction patients.

Myocardial infarction (MI) is a multi-factorial disease which claims many young lives. There are very few Indian studies that have investigated antiphospholipid antibodies (APLs) in MI patients. APLs have been implicated in arterial thrombosis including premature coronary artery and cerebrovascular thrombosis. In the present study, the prevalence of two clinically significant APLs--anticardiolipin antibody (ACA) and lupus anticoagulants (LA) in young MI patients was studied and compared with age- and sex-matched controls. Fifty healthy blood donors and 40 young MI patients (less than 45 yrs) diagnosed according to the American Heart Association guidelines were recruited for the study. The criteria for diagnosis were presence of atleast two of three classical findings including: clinical symptoms, diagnostic ECG, and presence of one or more cardiac biomarkers out of raised CK-MB isoform and T-troponin on serial measurement. LA and ACA were tested by lupus-sensitive activated partial thromboplastin time (aPTT) and ELISA respectively. Elevation of ACA was observed in 9 patients, while 6 were positive for LA. ACA of IgG isotype was detected in 8 patients. One patient had LA and raised ACA of IgG and IgM isotypes. Antiphospholipid antibodies were found to be significantly associated with MI in young patients, when considered together (p < 0.05) and in coronary thrombosis, mild elevation of ACA may be considered significant.

Molecular tissue typing in renal transplantation: Initial experience from a tertiary care Naval Hospital.

Background:During the last five years the proportion of living unrelated kidney transplants has increased and DNA tissue-typing methods have become popular in India. This study was carried out to compare the results of tissue - typing by serology and sequence specific primers (SSP) and study the usefulness of 'episode' allograft biopsies for diagnosis of acute graft dysfunction . Materials and Methods:DNA was extracted from whole blood using Qiagen kit. Samples from 60 individuals including thirty patients and their donors were typed by serology and SSP. Fifteen allograft biopsies were performed for suspected acute rejection (AR) cases. Results: Both alleles of HLA - A, B and DR antigen could be determined in 86, 65 and 90% of samples by SSP respectively. There was a discrepancy of 16-40% between SSP and serology. Acute rejection was confirmed in 8/15 biopsies. Graft survival rates were 83 and 76% at one and two years respectively. Neither the graft survival nor the number of AR episodes showed any correlation with the extent of HLA mismatch. SSP was useful in defining A*68, A*66, A*69 and A*33 alleles at private level and A*36, A*74 and A*03 alleles which were blank on serology. Conclusions: SSP has become popular in India due to its simplicity, superior results especially for class II HLA alleles: and episode allograft biopsy is adequate for follow-up of kidney recipients.