Beschreibung:
AbstractThe mechanisms underlying the impaired immune response in hemodialysis (HD) patients are not completely understood. The α‐defensins human neutrophil peptides‐1, 2, and 3 are low molecular weight peptides with antimicrobial activity and important effector molecules of innate immune responses. We now examined the expression of these peptides in HD patients. Seventy‐six patients on chronic HD treatment (mean time on HD 5.8 years; mean age 70 years) were studied and compared with 38 healthy volunteers and 20 patients with infections and normal renal function. Expression of α‐defensins was analyzed semiquantitatively in leukocytes on the messenger RNA (mRNA) level by reverse transcriptase polymerase chain reaction; the α‐defensin protein levels in serum were detected by enzyme‐linked immunosorbent assay. α‐Defensin concentrations (140 ± 10.5 ng/mL; mean ± standard error of the mean) as well as mRNA levels in leukocytes (82.9 ± 7.9 arbitrary units [a.u.]) in HD patients were not significantly different from those in healthy volunteers (156 ± 15.2 ng/mL; 81.4 ± 11.3 a.u.). Defensin levels were independent of the time of the patient on HD and their age. During infection periods (mean increase of the C‐reactive protein to 161 ± 17.3 mg/L), defensin serum levels increased to 321 ± 65 ng/mL (P < 0.005) and mRNA expression in leukocytes to 159 ± 19.2 a.u. (P < 0.05). These increases were not significantly different from those in patients with normal renal function (298 ± 46.8 ng/mL and 128 ± 9.1 a.u., respectively) suffering from infections (C‐reactive protein 222 ± 26.6 mg/L). Our results suggest that the impaired immune defense in dialysis patients is not due to a deficiency in α‐defensins in these patients as neither basal levels nor expression during infections were reduced compared with subjects with normal renal function.