Pro-calcitonin and inflammation in chronic hemodialysis

Procalcitonin (PCT) has emerged as a marker of infection, a frequent complication in hemodialysis (HD). We analyzed PCT levels in chronic non-acutely infected HD subjects, assessed its correlation with inflammatory and nutritional markers and propose a PCT reference value for non-infected HD patients. In an observational cross-sectional study, 48 chronic HD patients and 36 controls were analyzed. age, gender, time on HD; diabetes; vascular access, PCT, C-reactive protein (CRP), albumin, malnutrition inflammatory score (MIS), hematocrit, leukocyte count, and body mass index (BMI). Subsequently, control (G1, n = 36, 43%) vs. non-infected patients (G2, n = 48, 57%) groups were compared. In control subjects (G1), age: 54.3 ± 13.7 years, range (r): 30-81; males: 19 (53%); median PCT 0.034 ng/ml (r: 0.02-0.08); median CRP 0.80 mg/ dl (r: 0.36-3.9); p95 PCT level: 0.063 ng/ml. In G2, age: 60.2 ± 15.2 years; males 32 (67%), time on HD: 27.0 ± 24.4; diabetics: 19 (32%); median PCT: 0.26 ng/ml (r: 0.09-0.82); CRP: 1.1 mg/dl (r: 0.5-6.2); p95 PCT level: 0.8 ng/ml. In control subjects, PCT and CRP were significantly lower than in G2: PCT: 0.034 vs. 0.26 ng/ml, p = 0.0001; CRP: 0.8 vs. 1.1 mg/dl, p = 0.0004. PCT-CRP correlation in G2: p = 0.287, p = 0.048. PCT and CRP concentrations are elevated in chronic non-acutely infected HD subjects, independently of infection, diabetes and vascular access. A p95 PCT level of 0.8 ng/ml may be considered as the upper normal reference value in non-acutely infected HD subjects. The PCT cut-off level in HD is yet to be determined in HD.