Objective: To determine whether an allelic form of mannose-binding protein (MBP) incapable of activating complement is associated with susceptibility to systemic lupus erythematosus (SLE).
Methods: MBP allele frequencies were determined by amplification refractory mutation system-polymerase chain reaction in 102 white SLE patients and 136 controls.
Results: The MBP allele that is unable to activate complement was present in 42 SLE patients (41%) and in 41 controls (30%) (P = 0.08, odds ratio [OR] = 1.6, 95% confidence interval [95% CI] 1.0-2.8). The gene frequency of this allele was 0.25 in SLE patients and 0.19 in controls (P = 0.08, OR = 1.5, 95% CI 1.0-2.3).
Conclusion: Our results suggest that this allele of the MBP gene represents a minor risk factor for SLE.