Duplication mutation in CHIT1 gene is associated with poor response to medical therapy in patients affected with filarial chyluria

Effect of Clinical, Biochemical, and Genetic Variations on Medical Management in Filarial Chyluria: A Prospective Study at a Tertiary Care Centre in North India

Objective To analyze the effect of clinical, biochemical factors, and Mannose Binding Lectin 2 (MBL2) gene variations on medical management in filarial chyluria (FC) patients. Material and methods We conducted a study between March 2013 and April 2016. MBL2polymorphisms were genotyped in confirmed 101 medically-treated cases of FC. Demographic, clinical, and biochemical variables were compared between remission and failure groups. Genotyping of MBL2 codon 54 and promoter -221 were undertaken by polymerase chain reaction. Genotype frequencies were compared with clinical and biochemical variables and medical treatment outcomes (remission/failure). The association between genotypes and treatment response was estimated by OR and 95% CI and generated by the chi-square test. Results The mean age was 36.9±10.28-years and the male-female ratio was 3:1.2. Sixty-six patients had remission (Group-A) while 35 had recurrence (Group-B) at a mean follow-up of 21 months. The success rate for medical therapy was 65.35%. There was no statistical difference observed in the demographic profile of the two groups. On multivariate analysis, patients in Group-B had a higher grade of chyluria (p=0.005), had experienced greater number of disease attacks in the past (p=0.022), and had higher urinary triglyceride levels (TG) (p<0.001) as compared to Group-A patients. A significant association of MBL2 codon 54 genotypes was observed with the recurrent presentation of chyluria (p=0.044), grade of chyluria (p=0.028), and urinary TGs (p=0.001). However, genotype distribution at -221 did not show association with clinical and biochemical parameters of FC patients. The distribution of genotypes at codon 54 differed significantly between remission and failure/recurrence group; the variant genotype BB was significantly higher in the recurrence or failure group (OR:6.00; 95%CI, 1.00-35.91; p=0.050). However, frequencies of variant genotype YX and recessive group YX+XX of MBL2 -221 promoter was higher in remission group (OR:2.97;95%CI, 1.23-7.13; p=0.018 and OR:2.76; 95%CI, 1.80-6.50; p=0.020), respectively, showing that genetic variant may be associated with response to medical therapy. Conclusion Higher grade of chyluria, a higher number of disease attacks in the past, and higher urinary TGs levels were clinical predictors of poor response to medical treatment. Our results showed that the variants of MBL2 genes have an impact on treatment outcomes in FC patients. These observations may be limited by sample size.