Relationship between oligomer and functional serum mannose-binding lectin in chronic renal failure

Strong predictive value of mannose-binding lectin levels for cardiovascular risk of hemodialysis patients

Background

Hemodialysis patients have higher rates of cardiovascular morbidity and mortality compared to the general population. Mannose-binding lectin (MBL) plays an important role in the development of cardiovascular disease. In addition, hemodialysis alters MBL concentration and functional activity. The present study determines the predictive value of MBL levels for future cardiac events (C-event), cardiovascular events (CV-event) and all-cause mortality in HD patients.

Methods

We conducted a prospective study of 107 patients on maintenance hemodialysis. Plasma MBL, properdin, C3d and sC5b-9 was measured before and after one dialysis session. The association with future C-events, CV-events, and all-cause mortality was evaluated using Cox regression models.

Results

During median follow-up of 27 months, 36 participants developed 21 C-events and 36 CV-events, whereas 37 patients died. The incidence of C-events and CV-events was significantly higher in patients with low MBL levels (<319 ng/mL, lower quartile). In fully adjusted models, low MBL level was independently associated with increased CV-events (hazard ratio 3.98; 95 % CI 1.88–8.24; P < 0.001) and C-events (hazard ratio 3.96; 95 % CI 1.49–10.54; P = 0.006). No association was found between low MBL levels and all-cause mortality. Furthermore, MBL substantially improved risk prediction for CV-events beyond currently used clinical markers.

Conclusions

Low MBL levels are associated with a higher risk for future C-events and CV-events. Therefore, MBL levels may help to identify hemodialysis patients who are at risk to develop cardiovascular disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-0995-5) contains supplementary material, which is available to authorized users.

Mannan binding lectin: a two-faced regulator of renal allograft injury?

Complement activation plays an important role in the pathogenesis of renal allograft injury after kidney transplantation. There are three known pathways of complement activation, namely, classical, alternative, and lectin pathways. In renal allograft injury, contradictory results were reported about the role of the lectin pathway activated via mannan binding lectin (MBL). This Commentary discusses the findings by Bay et al. (this issue), who demonstrated a protective role for circulating MBL in the recipient, particularly in non-HLA immunized recipients.

Impact of mannose-binding lectin deficiency on radiocontrast-induced renal dysfunction: a post-hoc analysis of a multicenter randomized controlled trial

Background

Local renal ischemia is regarded as an important factor in the development of contrast-induced nephropathy (CIN). Mannose-binding lectin (MBL) is involved in the tissue damage during experimental ischemia/reperfusion injury of the kidneys. The aim of the present study was to investigate the association of MBL deficiency with radiocontrast-induced renal dysfunction in a large prospective cohort.

Methods

246 patients with advanced non–dialysis-dependent renal dysfunction who underwent radiographic contrast procedures were included in the study. Baseline serum MBL levels were analyzed according to the occurrence of a creatinine-based (increase of ≥0.5 mg/dL or ≥25% within 48 hours) or cystatin C-based (increase of ≥10% within 24 hours) CIN.

Results

The incidence of creatinine-based and cystatin C-based CIN was 6.5% and 24%, respectively. MBL levels were not associated with the occurrence of creatinine-based CIN. However, patients that experienced a cystatin C increase of ≥10% showed significantly higher MBL levels than patients with a rise of <10% (median 2885 (IQR 1193–4471) vs. 1997 (IQR 439–3504)ng/mL, p = 0.01). In logistic regression analysis MBL deficiency (MBL levels≤500 ng/ml) was identified as an inverse predictor of a cystatin C increase ≥10% (OR 0.34, 95% CI 0.15-0.8, p = 0.01).

Conclusion

MBL deficiency was associated with a reduced radiocontrast-induced renal dysfunction as reflected by the course of cystatin C. Our findings support a possible role of MBL in the pathogenesis of CIN.

Lectin complement pathway gene profile of the donor and recipient does not influence graft outcome after kidney transplantation

In kidney transplantation, complement activation was found to be induced by donor brain death, renal ischemia-reperfusion injury and allograft rejection. There are three known pathways of complement activation: the classical, lectin and the alternative pathway. The lectin complement pathway can be activated upon pattern recognition by mannan binding lectin (MBL) or ficolins (FCN). Single nucleotide polymorphisms (SNPs) in the genes encoding the lectin pathway proteins determine their functional activity and serum levels. The aim of this study was to investigate the role of the lectin gene profile of the donor and recipient on post-transplant outcome. A total of 12 functional SNPs in the MBL2, FCN2 and MBL-associated serine proteases 2 (MASP2) genes of 1271 donor-recipient pairs were determined. Lectin genotypic variants were analyzed for association with primary non-function (PNF), delayed graft function (DGF), biopsy proven acute rejection, death-censored graft survival and patient survival. Multivariate analyses found no association of donor and recipient MBL2 and MASP2 genotype with allograft outcome. Analysis of separate functional SNPs and haplotypes in the FCN2 gene of the donor and recipient did not reveal an association with transplant outcome. Also, the joint effect of the MBL2 and FCN2 genotype was not associated with allograft outcome.This study shows that the genetic profile of the lectin pathway of complement activation of the donor and recipient is not associated with allograft outcome after kidney transplantation.

Functional mannose-binding lectin levels in patients with end-stage renal disease on maintenance hemodialysis

BACKGROUND

Innate immunity is generally impaired in chronic renal failure (CRF). Mannose-binding lectin (MBL) has an important role in first-line host defense against pathogens via the lectin pathway. We recently reported that functional MBL was significantly lower in CRF patients than in healthy subjects. In this study, we aimed to determine whether functional MBL would be improved following hemodialysis (HD) therapy.

METHODS

This study included 22 patients with end-stage renal disease (ESRD) on maintenance HD. Functional MBL was measured every 6 months for 1 year after HD using an enzyme-linked immunosorbent assay.

RESULTS

Median serum functional MBL levels of ESRD patients were significantly higher after 6 and 12 months than at the start of HD therapy (p < 0.05 and p < 0.01, respectively). Furthermore, median functional MBL levels at 12 months were significantly higher than those at 6 months (p < 0.05).

CONCLUSIONS

We found significant increases in serum functional MBL levels in patients on HD. Our results indicated that HD tailored to remove uremic toxins could improve functional MBL levels in these patients.