25(OH) vitamin D levels and effects on children WHO underwent liver transplantation

Objective : Vitamin D has effects on metabolism and it is also shown that it has functions on immune system. The effects of vitamin D in organ transplantation are being investigated, but research on children is limited. We aimed to determine the levels of vitamin D before and after liver transplantation in children and investigate the relationship between the severity of liver failure and vitamin D levels and to investigate the effects of these levels on liver rejection. Material and Method : 138 of 212 children who had liver transplantation between 2003 and 2015 in BÜTF hospital, were enrolled in the study. Patients divided to four main diagnostic groups as; cholestasis, cirrhosis, metabolic and acute liver diseases. Patient survival, biopsy-proven rejections and RAI scores, all vitamin D levels before and after transplantation and simultaneuos liver function tests, season of vitamin D measurement were recorded. PELD and Child-Pugh scores were calculated in cholestasis and cirrhosis group. Results: Vitamin D levels in 90 patients examined before transplantation was deficient in 36.6%; insufficient in 23.3% and normal in 40%. After transplantation vitamin D levels were deficient in 27.5%; insufficient in 13.7% and normal in 58.7% of 109 patients. When 61 case whose vitamin D levels were mesasured both before and after transplantation, there was an increase in the proportion of normal vitamin D in post transplant period (p=0,01). Patients with cholestasis had significantly lower vitamin D levels before transplantation compared to other diagnostic groups (mean values were 22.7±19.3 and 28.8±22.7 ng/mL respectively) (p=0,04). This difference disappeared after the transplantation. In the cholestasis and cirrhosis, negative correlation between D vitamine level and total and direct bilirubin was observed (p=0,01, r:0,29 and p=0,007 r:0,30 respectively). In the whole patient group, there was a positive correlation between D vitamin level and serum albumin level (p=0,05 r=0,20). There was no relation between vitamin D and PELD values, RAI scores, post-transplant mortality, season of vitamin D measurement. Conclusion: In our study, no association found with vitamin D and rejection or survival in children with liver transplantation. However, low D vitamin levels and impairment of liver function were associated. D vitamine levels tended to increase after transplantation.Despite oral vitamin D support, in liver transplantation candidates (especially cases accompanied with cholestasis) vitamin D levels were low. We recommend that these patients needs close monitoring and additional vitamin D doses. Key Words: 25(OH)D, Vitamin D, Liver Transplantation, Rejection, Cholestasis