L-FABP and IL-6 as markers of chronic kidney damage in children after hemolytic uremic syndrome

Background. Hemolytic-uremic syndrome (HUS) is a form of thrombotic microangiopathy, in the course of which some patients may develop chronic kidney disease (CKD). From a clinical point of view, it is important to search for markers that allow for early identification of patients at risk of a pool prognosis. Objectives. The study evaluated the serum and urine levels of liver-type fatty acid binding protein (L-FABP) and interleukin 6 (IL-6). Material and methods. The study was conducted in 29 children with a history of HUS. The relationship between L-FABP and IL-6 and anthropometric measurements, the value of estimated glomerular filtration rate (eGFR) and albuminuria were additionally evaluated. Results. In children after HUS, L-FABP and IL-6 concentration in both serum and urine was significantly higher in comparison to the control group. No differences in L-FABP and IL-6 concentration in serum and urine depending on the type of HUS and gender were noted. Correlation between L-FABP and IL-6 in serum and urine with eGFR and urine albumin-creatinine ratio (ACR) in the total group of patients after HUS was not detected. In the group of children after 6 month observation after HUS, a negative correlation of L-FABP concentration with eGFR was found. Conclusions. The results indicate that the higher concentration of L-FABP in serum and urine of children with a history of HUS can be the result of protracted injuiy initiated during the acute phase of the disease. Lack of correlation of L-FABP concentration with the ACR may be associated with a short (less than 6 months) observation after acute renal failure or merely temporary renal tubular damage in the acute phase of the disease. In contrast, higher levels of IL-6 in serum and urine in children after HUS compared to healthy children and the negative correlation of L-FABP concentration and eGFR in children after 6 month observation after HUS may confirm their participation in CKD. Thus, L-FABP and IL-6 seem to be good biomarkers of chronic kidney damage in survivors of the acute phase of HUS.