Increased serum complement component 3 and mannose-binding lectin levels in adult Chinese patients with chronic rhinosinusitis

Abstract

Objective: To study the immune function of adult Chinese patients with chronic rhinosinusitis (CRS) to elucidate its potential role in the pathogenesis of CRS.

Methods: A prospective three-arm case-control study. The study population comprised 72 CRS patients without nasal polyps (NPs), 95 CRS patients with NPs, and 110 healthy controls. The concentrations of serum immunoglobulin A (IgA), M (IgM), G (IgG), IgG subclasses (IgG1-4), complement component 3 (C3), and complement component 4 (C4) were measured by nephelometry. Serum mannose-binding lectin (MBL) levels were analyzed by enzyme-linked immunosorbent assay. All CRS patients had a complete blood count with differential, atopic status evaluation, coronal computed tomographic (CT) scan of the sinuses, and nasal endoscopy.

Results: Frequency of immunoglobulin, C3, C4, or MBL deficiency showed no difference among groups. The prevalence of coexistence of MBL and immunoglobulin or complement component deficiency did not differ significantly among groups either. However, compared with controls, decreased IgG3 levels were found in CRS patients without NPs, and increased C3 and MBL levels was found in both CRS patients with and without NPs. Moreover, MBL levels were significantly higher in CRS patients with NPs than in CRS patients without NPs, which positively correlated with extent of disease seen on CT scan and endoscopy, and peripheral eosinophil count.

Conclusions: Immunoglobulin, C3, C4, and MBL deficiency is not the main cause of CRS in adult Chinese patients. However, on the contrary, increased C3 and MBL levels in serum might play a modulatory role in CRS development.