SERPINB11 variant-related liver injury in STEC-HUS: case reports and literature review

Background Liver damage is uncommon in Shiga toxin-producing Escherichia coli– associated hemolytic uremic syndrome (STEC-HUS). Herein, we present two cases with a diagnosis of STEC-HUS that progressed to liver damage, with findings presumably related to the SERPINB11 gene c.268G > T (p.Glu90Ter) variant. Case-diagnosis/treatment Two boys aged 3 and 2 years, respectively, were referred to our clinic with a preliminary diagnosis of STEC-HUS. The patients had low hemoglobin, thrombocyte, and haptoglobin levels but high levels of lactic dehydrogenase, urea, creatinine, and schistocytes in peripheral smears. Escherichia coli O157:H7 was detected in their stool samples. The patients underwent hemodialysis, plasma exchange, and supportive treatments. Meanwhile, cholestasis developed in the patients, resulting in elevated total bilirubin levels. During the follow-up period, kidney function recovered completely; however, liver function did not improve, and one patient developed chronic liver damage. Gene mutations that may cause liver damage were investigated, and c.268G > T (p.Glu90Ter) homozygous and heterozygous variants were detected in exon 9 of the SERPINB11 gene in the patients. Conclusions Our patients presented with kidney impairment and liver malfunction. Hepatic involvement in STEC-HUS may result from ischemia, hemolysis, and endothelial damage in the hepatic vessels. Liver injury in STEC-HUS cases may be associated with the homozygous SERPINB11 gene c.268G > T (p.Glu90Ter) variant.