Madurai: Tamil Nadu has over the years emerged as a pioneering State in India in organ donation and transplantation due to the focus on awareness programmes and establishment of regulatory mechanisms.
However, little known and rarely recognised in this progress is the contribution for 33 years by Human Leukocyte Antigen (HLA) Laboratory at the Department of Immunology, Madurai Kamaraj University, which carries out crucial and mandatory ‘tissue cross-match’ between the donor and the receiver for organ transplants.
“In simple terms, we test whether the receiver’s body will accept the graft from the donor or the antibodies in its immune system will reject the graft,” said K. Balakrishnan, Associate Professor and Head, Department of Immunology.
According to him, the journey started in 1980-81 when RM Pitchappan, who was a Reader in the newly formed Immunology Department, participated in a workshop in Paris with Jean Dausset, who won Nobel prize in 1980 for the discovery of the genes that form the major histocompatibility complex (MHC), also called HLAs (when referring to humans), which determines compatibility between the tissues of two individuals.
Inspired by the workshop and realising the potential for further research in the field, Mr. Pitchappan and others in the department started HLA Laboratory in the MKU.
“In those days, apart from All India Institute of Medical Sciences in Delhi, only CMC Vellore was carrying out organ transplants in considerable numbers. We used to get samples of CMC patients from across South India for tissue matching,” said Mr. Balakrishnan.
Today, the MKU has tie-up with around 25 major hospitals across Tamil Nadu and the lab carries out, on an average, 250 tests for organ transplants, mainly kidney transplants, every year. “Though a few private labs and hospitals now have the facilities to do the test, the MKU is the only government institution in the State with the lab. A majority of the staff in other facilities were also trained at HLA Lab here,” he said.
According to Mr. Balakrishnan, two tests are performed between the donor and the receiver for organ transplants at HLA Lab – first, a ‘tissue cross-match test’, which will determine whether the transplant could be carried out or not, and second, the HLA typing, which helps in determining how successful the transplant will be.
The tissue cross-match test involves incubating the lymphocytes isolated from the donor’s blood cells with the serum of the receiver. “If the antibodies in the serum react against and kill the donor’s cells, it is a positive cross-match. It means there is no compatibility and transplant cannot take place,” he said.
The subsequent HLA matching test becomes necessary only when the tissue cross-match test is negative.
HLA matching involves extracting DNAs and then subjecting them to Polymerase chain reaction (PCR). “The PCR multiplies specific DNA regions, in our case the HLA gene complex, so that they can be easily studied. These multiplied genes are then subjected to a process called gel electrophoresis, through which the exact arrangement and characters of the HLA gene complex can be visualised,” Mr. Balakrishnan said.
The procedure will be carried out separately for the donors and the receivers, and the outcome will be compared to see similarities between the HLAs. “Within blood relatives, similarities will be high. Higher the similarity, easier the receiver’s acceptance of the graft and its longevity,” he said, adding that the test was done only for live donors and not in case of cadaveric transplants.
K. Sampath Kumar, Head, Department of Nephrology, Meenakshi Mission Hospital and Research Centre, who has been using the MKU’s facility for his patients, said the HLA typing also helped in determining the magnitude and nature of immuno-suppressant drugs to be administered to the receiver to make the body accept the graft.
The MKU lab has also been a source of income. In the past three years, it generated an income of Rs. 28.14 lakh, 30 per cent of which was shared with the university and the remaining amount used for maintenance and operation of the lab.
“This comes primarily through what we charge for the tests, which is less than 25 per cent of what is charged by private players, and the training provided for staff of private laboratories,” Mr. Balakrishnan said.
Stressing the importance of having separate institutions like the lab at the MKU to perform these tests, Dr. Sampath Kumar said having such labs within hospitals carried the risk of manipulation of results to perform transplants even if the match was not good.
However, he highlighted the need for more trained professionals in the field as the need for such tests was on the rise. “There is a considerable demand and opportunities in the western countries for professionals in this field, and hence a majority of the trained people do not stay here,” he said.
Acknowledging the brain drain, Mr. Balakrishnan said the university was planning to take more research scholars. “Since studying the HLAs has wider ramifications in developing vaccines and other drugs, we are increasing our collaboration with other institutions to widen our research activities. We hope it will help in retaining more people here,” Mr. Balakrishnan said.
