title: Impaired immune defense in hemodialysis patients: role of α-defensins?
abstract: The 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.
authors.affiliation: Department of Nephrology and Rheumatology, Georg-August-University, Göttingen, Germany; Department of Nephrology and Hypertension, Sozialstiftung Bamberg, Bamberg, Germany.
authors.forename: Clemens
authors.initials: C
authors.lastname: Grupp
authors.forename: Ilka
authors.initials: I
authors.lastname: Troche-Polzien
authors.forename: Christian
authors.initials: C
authors.lastname: Noeding
authors.forename: Claudia A
authors.initials: CA
authors.lastname: Mueller
authors.forename: Gerhard A
authors.initials: GA
authors.lastname: Mueller
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002097:C-Reactive Protein / Q000276:immunology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007239:Infections / Q000276:immunology; D007676:Kidney Failure, Chronic / Q000276:immunology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis / Q000009:adverse effects / Q000379:methods*; D055815:Young Adult; D023084:alpha-Defensins / Q000096:biosynthesis / Q000097:blood / Q000276:immunology*
chemical_list: D023084:alpha-Defensins; D002097:C-Reactive Protein
keywords: HNP; antimicrobial peptides; infection; innate immunity; neutrophils; renal failure