Mannose-binding lectin deficiency confers risk for bacterial infections in a large Hungarian cohort of patients with liver cirrhosis.

Background & Aims: Mannose-binding lectin (MBL) is a serum lectin synthesized by the liver and involved in innate host defense. MBL deficiency increases the risk of various infectious diseases mostly in immune-deficient conditions. Bacterial infections are a significant cause of morbidity and mortality in liver cirrhosis due to the relative immuncompromised state.

Methods: Sera of 929 patients with various chronic liver diseases [autoimmune liver diseases (ALD), 406; viral hepatitis C (HCV), 185; and liver cirrhosis (LC) with various etiologies, 338] and 296 healthy controls (HC) were assayed for MBL concentration. Furthermore, a follow-up, observational study was conducted to assess MBL level as a risk factor for clinically significant bacterial infections in cirrhotic patients.

Results: MBL level and the prevalence of absolute MBL deficiency (<100 ng/ml) was not significantly different between patients and controls (ALD: 14.5%, HCV: 11.9%, LC: 10.7%, HC: 15.6%). In cirrhotic patients, the risk for infection was significantly higher among MBL deficient subjects as compared to non-deficient ones (50.0% vs. 31.8%, p=0.039). In a logistic regression analysis, MBL deficiency was an independent risk factor for infections (OR: 2.14 95% CI: 1.03-4.45, p=0.04) after adjusting for Child-Pugh score, co-morbidities, gender, and age. In a Kaplan-Meier analysis, MBL deficiency was associated with a shorter time to develop the first infectious complication (median days: 579 vs. 944, pBreslow=0.016, pLogRank=0.027) and was identified as an independent predictor in a multivariate Cox-regression analysis (p=0.003, OR: 2.33, 95% CI: 1.34-4.03).

Conclusions: MBL deficiency is associated with a higher probability and shorter time of developing infections in liver cirrhosis, further supporting the impact of the MBL molecule on the host defense.