Functional mannose binding lectin levels in patients with pediatric onset systemic lupus erythematosus in remission.

BACKGROUND: Complement system plays a crucial role in the pathogenesis of systemic lupus erythematosus (SLE). Excessive activation of complement causes tissue injury and SLE occurrence is typically associated with congenital deficiencies of the early components of the classical complement pathway. Mannose-binding lectin (MBL) is recognized as important causative factor in the etio-pathogenesis of SLE and MBL-2 gene has evolved as a candidate gene for SLE susceptibility.

AIM: This study was done to assess the functional MBL (fMBL) level in SLE patients in remission and its co-relation with disease severity and outcome.

METHODS: Functional MBL levels were compared with age and sex matched healthy controls and were correlated with duration of illness,complement levels and anti-double- stranded DNA antibody levels.

RESULTS: Mean fMBL level in patients was found to be 696.19 ± 408.98 U/mL and 579.52 ± 393.87 U/mL in the control group. Four children had very low fMBL levels (< 40 U/mL). Functional MBL levels were higher in patients with SLE even when the disease was in remission as compared to healthy controls, although not statistically significant.

CONCLUSION: Large variation exists in fMBL levels in patients with SLE even when in remission. Very low fMBL levels were found in some children with younger age of onset of SLE, multisystem involvement and severe course of the disease. Positive correlation of MBL levels with anti-ds DNA titers suggest that its values vary with activity and could be a potential biomarker of the disease.