ESPN 51th Annual Meeting

ESPN 2018


 
REPEATED SPONTANEOUS REMISSION OF ATYPICAL HEMOLYTIC-UREMIC SYNDROME CAUSED BY INFLUENZA – A CASE REPORT
HANA FLÖGELOVá 1 JANA VOLEJNíKOVá 1 INGRID HRACHOVINOVá 2 ZOLTáN PROHáSZKA 3

1- DEPARTMENT OF PEDIATRICS, FACULTY OF MEDICINE AND DENTISTRY, PALACKý UNIVERSITY AND UNIVERSITY HOSPITAL OLOMOUC, CZECH REPUBLIC
2- INSTITUTE OF HEMATOLOGY AND BLOOD TRANSFUSION (IHBT), PRAGUE, CZECH REPUBLIC
3- RESEARCH LABORATORY, SEMMELWEIS UNIVERSITY, 3RD DEPARTMENT OF INTERNAL MEDICINE, BUDAPEST, HUNGARY
 
Introduction:

Reported is spontaneous recovery of episodes of atypical hemolytic-uremic syndrome (aHUS) in a 17-year-old male. In both cases, the condition was caused by seasonal influenza (first, influenza A/H3; second, after 1 year, influenza B).

Material and methods:

As early as when the patient first presented with aHUS, decreased expression of CD46 (MCP) on granulocytes was found, suggesting complement-mediated HUS. As the patient’s clinical condition was stable and, from Day 3 on, laboratory test results started to improve, a decision was made not to administer eculizumab and to initiate symptomatic therapy only. However, eculizumab was at hand in case his clinical condition deteriorated. In both episodes, spontaneous remission of HUS was observed. Given the presumed risk of HUS relapse, genetic tests were carried out following the first episode.

Results:

The patient was confirmed to have a mutation in MCP (heterozygote for the p.C35Y mutation) and the high-risk MCPggaac haplotype of the CD46 gene (Research Laboratory Budapest). We assume that the mutation together with the high-risk haplotype played a pathogenic role in the development of complement-mediated aHUS, with influenza triggering the condition. Genetic tests were also performed in the patient’s parents. His father is a heterozygote for the p.C35Y mutation in MCP and his mother is a heterozygote for the high-risk MCPggaac haplotype of the CD46 gene. In the future, the patient is at risk for relapse of aHUS with a worse course, requiring plasma exchange or, if this fails, eculizumab therapy. 

Conclusions:

The case report confirmed that in an individual with a mutation in MCP, seasonal influenza may be a triggering factor for aHUS and that spontaneous remission is possible. Genetic tests in patients with aHUS contribute to better understanding of aHUS.