ESPN 51th Annual Meeting

ESPN 2018


 
TWO ATYPICAL HUS CASES WITH POSITIVE COMPLEMENT FACTOR B MUTATION
Ipek Kaplan Bulut 1 Sevgin Taner 1 Caner Kabasakal 1

1- Ege University Faculty of Medicine, Pediatric Nephrology
 
Introduction:

Atypical Hemolytic Uremic Syndrome (HUS) is mainly associated with dysregulation of the complement alternative pathway. Complement factor B mutations are one of the rare causes.

Material and methods:

Here we represent 2 cases of atypical HUS with renal involvement whom homozygous Complement Factor B mutations are positive and recovered with Eculizumab.

 

Results:

CASE 1

Seven year-old male patient referred to our hospital with bloody diarrhea, and anuria for 2 days. On physical examination, blood pressure was high. There was pretibial and orbital edema. Laboratuary findings were; hemoglobin:6.5 g/dL, plt:38x10³/μL, urea:332 mg/dL, creatinine:8.3  mg/dL, uric acid:16 mg/dL, LDH:2577 U/L. Schistocytes were shown in blood smear and direct coombs test was negative. ADAMTS-13 activity was in the normal. Stool cultures were negative. Hemodialysis and plasma exchange sessions were performed. On 7th day of follow up he started to urinate. There was nephrotic proteinuria (130 mg/m2/h) and creatinine levels were still high for age (0.9 mg/dL). After Eculizimab started urea decreased to 30 mg/dL and creatinin to 0.5 mg/dL and also urinary protein excretion was normal. Genetic analysis showed homozygous mutation of compleman factor B.

CASE 2

Thirty months-old male patient admitted to us with bloody diarrhea. On physical examination pretibial and orbital edema detected. His hemoglobin 9.3 g/dL, plt:40x10³/μL, urea:104 mg/dL, creatinine:2 mg/dL, uric acid:9.1 mg/dL, LDH:2150 U/L. There were schistocytes in blood smear and D.Coombs and stool cultures were negative. ADAMTS-13 activity was normal. Despite 14 days of plasma infusion therapy there have been still intravascular hemolysis and severe nephrotic proteinuria (650 mg/m2/h). His urea was 43 mg/dL and creatinin was 0.7 mg/dL. After eculizumab was given to the patient, proteinuria regressed to non-nephrotic levels (spot urine protein/creatinin:0,6). The patients genetic analysis also showed homozygous mutation of compleman factor B.   

Conclusions:

We believe that further investigation should be done in terms of treatment and follow-up in patients with atypical hemolytic uremic syndrome.