Hypoalbuminemia: a risk factor in patients with STEC-associated hemolytic uremic syndrome

We aimed to determine the prevalence of hypoalbuminemia in STEC-HUS patients with hemorrhagic colitis (HC) and whether serum albumin level (SAL), leukocyte count, hematocrit and serum sodium level (SSL) are prognostic markers of HC, central nervous system disease (CNSd) and/or dialysis requirement and evaluate if hypoalbuminemia is associated with fecal protein losses.

We prospectively evaluated STEC-HUS patients treated at our institution from 9/2011 to 2/2019, analyzing the presence of HC, CNSd and dialysis requirement and SAL, SSL, leukocytes, hematocrit and α1-antitrypsin clearance.

We evaluated 98 patients, with mean age of 33.3 months. SAL ≤ 29.5 g/l, > 24,600 leukocytes/mm³ and hematocrit > 30% behave as independent prognostic markers for HC. SAL ≤ 28 g/l, > 25,200 leukocytes/mm³ and hematocrit > 30% behave as prognostic markers for CNSd. SAL ≤ 31.6 g/l, > 13,800 leukocytes/mm³, hematocrit > 18.9% and hyponatremia (≤ 132 mEq/l) behave as prognostic markers for dialysis requirement. However, in multivariate logistic regression models, only hypoalbuminemia behaved as a risk factor for HC, CNSd and dialysis. α1-antitrypsin clearance was performed in 69 patients and was high in 9/69 (13%), only 4 with HC. No significant association was observed between α1-antitrypsin clearance and albuminemia (χ² = 0.1076, p = 0.7429) as well as α1-antitrypsin clearance and HC (χ² = 1.7892, p = 0.1810).

Almost all patients with HC had hypoalbuminemia, which behaves as a risk factor for HC, CNSd and dialysis requirement. No significant association was observed between elevated α1-antitrypsin clearance and hypoalbuminemia nor between elevated α1-antitrypsin clearance and HC. These findings could be related to the small number of evaluated patients.