Effect of extreme conditions of Antarctica on human leukocyte antigen-G in Indian expeditioners

BACKGROUND & OBJECTIVES Immune activation and inflammation play critical roles in the stressful environmental conditions like high altitude, extreme cold, etc. Human leukocyte antigen-G (HLA-G) is a non classical major histocompatiblity complex class I (MHC class- I) protein, upregulated in the context of transplantation, malignancy and inflammation. We hypothesized serum HLA-G as a possible stress biomarker and studied levels of soluble form of HLA-G (sHLA-G) in Indian Antarctic expeditioners. METHODS sHLA-G ELISA was performed in the serum of summer (n=27) and winter (n=22) Indian Antarctic expeditioners. The summer expeditioners were evaluated at three different time points, i.e. before leaving India, after one month ship borne journey, and after staying one month at Indian research base, Maitri in Antarctica, while winter expeditioners were evaluated at five different time points, i.e. before leaving India, and in the month of March, May, August and November at Antarctica. RESULTS o0 ne month ship borne journey did not cause any significant change in the sHLA-G level as compared to the baseline level of the summer expeditioners. sHLA-G levels were not changed significantly in the months of March, May, August and November as compared to the baseline level of the winter expeditioners. INTERPRETATION & CONCLUSIONS Our results indicated that the extreme conditions of Antarctica did not cause any significant change in the sHLA-G level in both summer and winter expeditioners.