Impact of Exon 1 polymorphism in the MBL2 gene on MBL serum levels and infection susceptibility in acute lymphoid leukemia.

Polymorphisms in the MBL2 gene exon 1 can decrease serum levels of mannose-binding lectin (MBL), increasing the risk of infection in immunocompromised individuals. This study evaluated the association between the polymorphism in exon 1 of the MBL2 gene, genotypes, serum MBL levels, and infection in 122 patients with acute lymphoid leukemia (ALL). The MBLA allele exhibited the highest frequency (0.37) within the study population. The MBLD (0.32) was the predominant variant. The combined frequency of O polymorphic alleles (either B or D) was 0.63. The frequencies of the A/A, A/O and O/O genotypes were 0.13, 0.49 and 0.38, respectively. All patients exhibited consistently low levels of serum MBL, irrespective of their exon 1 genotype. Parasitic infections (n = 103), bacterial (n = 69) and viral (n = 48). A/O genotype (0.49) had higher infection rates, A/A (0.13) had lower rates, and O/O showed increased viral susceptibility (OR: 0.37; 95% CI 0.13-1.06; p = 0.05). Our findings demonstrated that the study population were MBL-deficient, regardless of their MLB2 genotype. Individuals with the A/O genotype had more infections, while those with the O/O genotype appeared more susceptible to viral infections. These findings highlight the impact of MBL levels and genetic variants on infection susceptibility in ALL patients.