title: High alpha-defensin levels in patients with systemic lupus erythematosus.
abstract: Innate immunity plays a role in systemic lupus erythematosus (SLE). Our objective was to determine the levels of defensins, which are antimicrobial and immunomodulatory polypeptides, in SLE. Sera from SLE patients and healthy controls were tested for pro-inflammatory human beta-defensin 2 (hBD-2) and for alpha-defensin human neutrophil peptide 1 (HNP-1). hBD-2 could not be detected by enzyme-linked immunosorbent assay (ELISA) and its mRNA levels were low in SLE patients and similar to those found in controls. In contrast, the mean alpha-defensin level in the sera of all SLE patients (11.07 +/- 13.92 ng/microl) was significantly higher than that of controls (0.12 +/- 0.07 ng/microl). Moreover, 60% of patients demonstrated very high serum levels (18.5 +/- 13.36 ng/microl) and 50% showed elevated gene expression in polymorphonuclear cells. High alpha-defensin levels correlated with disease activity, but not with neutrophil count. Thus, activation and degranulation of neutrophils led to alpha-defensin secretion in SLE patients. Given the immunomodulatory role of alpha-defensins, it is possible that their secretion may activate the adaptive immune system leading to a systemic response.
authors.affiliation: Department of Medicine B, Kaplan Medical Center, Rehovot, Israel.
authors.forename: Zev M
authors.initials: ZM
authors.lastname: Sthoeger
authors.forename: Shira
authors.initials: S
authors.lastname: Bezalel
authors.forename: Nava
authors.initials: N
authors.lastname: Chapnik
authors.forename: Ilan
authors.initials: I
authors.lastname: Asher
authors.forename: Oren
authors.initials: O
authors.lastname: Froy
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D015870:Gene Expression / Q000276:immunology; D006801:Humans; D007958:Leukocyte Count; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000276:immunology; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000235:genetics; D012720:Severity of Illness Index; D055815:Young Adult; D023084:alpha-Defensins / Q000097:blood* / Q000235:genetics; D023083:beta-Defensins / Q000097:blood / Q000235:genetics
chemical_list: C106641:DEFB4A protein, human; D012333:RNA, Messenger; D023084:alpha-Defensins; D023083:beta-Defensins; C406413:human neutrophil peptide 1; C406427:human neutrophil peptide 3