Pant Shriya, Agarwal Jyotsna, Goel Apul, Gangwar Pravin K, Waseem Mohammad, Gupta Prashant, Sankhwar Satya N, Purkait Bimalesh
PhD Student, Department of Urology, King George's Medical University , Lucknow, Uttar Pradesh, India .
Professor, Department of Microbiology, King George's Medical University , Lucknow, Uttar Pradesh, India .
J Clin Diagn Res. 2016 Sep;10(9):PC01-PC04. doi: 10.7860/JCDR/2016/20987.8423. Epub 2016 Sep 1.
Chyluria which is endemic in many parts of the world is mainly caused by (chitotriosidase) is produced by macrophages and plays an important role in the defense against chitin containing pathogen such as filarial parasite. Variation in the coding region with 24 bp duplication allele results in reduced activity that enhance the survival of parasite which may play a role in the occurrence of disease.
To examine the role of 24bp duplication of gene in patients of filarial chyluria (FC).
A case-control study was carried out where 155 confirmed FC patients and equal number of age-, sex- and residence-matched controls without any symptoms or signs of lymphatic filariasis, confirmed by negative immunochromatographic card test (ICT) and IgG/IgM combo rapid antibody test, from a hospital-based population were enrolled. Filarial aetiology was confirmed on the basis of DEC-provocative test (Giemsa staining), ICT and IgG/IgM- antifiarial antibody test. The patients positive by either of these tests were enrolled as FC cases. 24bp duplication in gene in FC was detected by the product size 99bp of amplified gene using polymerase chain reaction.
The mean ages of patients and controls were 38.25±12.09 and 35.45±12.53 years, respectively while male: female ratio was 2.4:1. The mean duration of illness in chyluria patients was 62.81±60.83 months and mean number of episodes was 2.54±1.11. Homozygous wild type, heterozygous and homozygous mutant frequencies were 10.3%, 81.3% and 8.4% in FC patients and 18.7%, 75.5%, and 5.8% in controls, respectively. The 24bp duplication in gene showed a significant association in Heterozygous (HT) genotype with Odd Ratio (OR) of 1.95, 95% Confidence Interval (CI) (1.01-3.77); p=0.04. However, the homozygous mutant genotype (TT) was found to be non-significant with OR of 2.61, 95% CI (0.91-7.45); p=0.07. The combination of both HT+TT was also found to be significant with OR of 2.00, 95% CI (1.03-3.85); p=0.03.
In this study from Northern India, gene polymorphism showed an influence as a possible risk factor for susceptibility to FC. Further studies need to be done on a larger number of FC patients in different regions of the country.
乳糜尿在世界许多地区呈地方性流行，主要由（几丁质酶）引起，该酶由巨噬细胞产生，在抵御含几丁质病原体（如丝虫寄生虫）的防御中起重要作用。编码区24bp重复等位基因的变异导致活性降低，从而提高了寄生虫的存活率，这可能在疾病的发生中起作用。
研究几丁质酶基因24bp重复在丝虫性乳糜尿（FC）患者中的作用。
进行了一项病例对照研究，从一家医院的人群中纳入了155例确诊的FC患者以及数量相等的年龄、性别和居住地匹配的对照，这些对照无任何淋巴丝虫病的症状或体征，经免疫层析卡试验（ICT）阴性和IgG/IgM联合快速抗体试验确认。根据乙胺嗪激发试验（吉姆萨染色）、ICT和IgG/IgM抗丝虫抗体试验确认丝虫病因。通过这些试验中任何一项呈阳性的患者被纳入FC病例。使用聚合酶链反应通过扩增基因的产物大小99bp检测FC中几丁质酶基因的24bp重复。
患者和对照的平均年龄分别为38.25±12.09岁和35.45±12.53岁，男女比例为2.4:1。乳糜尿患者的平均病程为62.81±60.83个月，平均发作次数为2.54±1.11次。FC患者中纯合野生型、杂合型和纯合突变型频率分别为1０.3%、81.3%和8.4%，对照中分别为18.7%、75.5%和5.8%。几丁质酶基因的24bp重复在杂合（HT）基因型中显示出显著关联，优势比（OR）为1.95，95%置信区间（CI）（1.01 - 3.77）；p = 0.04。然而，纯合突变基因型（TT）被发现无统计学意义，OR为2.61，95% CI（0.91 - 7.45）；p = 0.07。HT + TT两者的组合也被发现具有统计学意义，OR为2.00，95% CI（1.03 - 3.85）；p = 0.03。
在这项来自印度北部的研究中，几丁质酶基因多态性显示出作为FC易感性的可能危险因素的影响。需要在该国不同地区对更多的FC患者进行进一步研究。
