Ansari Ayesha Arooj, Tipu Hamid Nawaz, Ahmad Dawood, Farhan Muhammad
Department of Immunology, Armed Forces Institute of Pathology, CMH Rawalpindi, Pakistan.
Armed Force Bone Marrow Transplant Center, CMH Rawalpindi, Pakistan.
J Coll Physicians Surg Pak. 2020 Aug;30(8):790-795. doi: 10.29271/jcpsp.2020.08.790.
To investigate the association of C4A null allele (C4AQ0) with systemic lupus erythematosus (SLE) and determine the clinical presentation of SLE in relation to C4A null allele.
Descriptive study.
Armed Forces Institute of Pathology (AFIP), Rawalpindi, Immunology Department, from December 2018 to December 2019.
Patients referred to AFIP, who fulfilled American College of Rheumatology (ACR) criteria of 1997 for diagnosis of SLE were included in the study. Approval from the Institutional Ethical Review Board was taken. C4A and C4B null alleles were determined in 66 SLE patients and 40 age- and gender-matched healthy controls by polymerase chain reaction (PCR) using sequence-specific primers (PCR-SSP). Various clinical features and laboratory findings in the SLE patients were analysed in relation with C4A null allele.
The mean age of the study population was 30.56 ±10.08 years. C4A null allele was detected in 7 (10.6%) patients; whereas, C4B null allele was detected in only two (3%) patients. SLE patients with C4A null allele had increased incidence of arthritis (100%) and renal damage (85.7%); compared to those with normal C4A allele, 57.6% and 32%, respectively. Fisher's Exact test revealed strong association of C4A null allele with arthritis and renal damage, (p = 0.039 and 0.01, respectively).
Homozygous absence of C4A alleles was encountered in 10.6% of Pakistani patients of SLE and is closely related with clinical features of arthritis and renal damage. Knowledge of C4A null allele in SLE patients at diagnosis can predict disease course. Key Words: SLE, C4A null alleles, C4AQ0, Homozygous C4A deficiency.
研究C4A无效等位基因（C4AQ0）与系统性红斑狼疮（SLE）的关联，并确定与C4A无效等位基因相关的SLE临床表现。
描述性研究。
2018年12月至2019年12月，拉瓦尔品第武装部队病理研究所（AFIP）免疫科。
纳入转诊至AFIP且符合1997年美国风湿病学会（ACR）SLE诊断标准的患者。获得了机构伦理审查委员会的批准。采用序列特异性引物聚合酶链反应（PCR-SSP）检测66例SLE患者和40例年龄及性别匹配的健康对照者的C4A和C4B无效等位基因。分析SLE患者的各种临床特征和实验室检查结果与C4A无效等位基因的关系。
研究人群的平均年龄为30.56±10.08岁。7例（10.6%）患者检测到C4A无效等位基因；而仅2例（3%）患者检测到C4B无效等位基因。具有C4A无效等位基因的SLE患者关节炎（100%）和肾损害（85.7%）的发生率增加；相比之下，C4A等位基因正常的患者分别为57.6%和32%。Fisher精确检验显示C4A无效等位基因与关节炎和肾损害密切相关（p分别为0.039和0.01）。
10.6%的巴基斯坦SLE患者存在C4A等位基因纯合缺失，且与关节炎和肾损害的临床特征密切相关。在诊断时了解SLE患者的C4A无效等位基因可预测疾病进程。关键词：SLE、C4A无效等位基因、C4AQ0、C4A纯合缺乏
