Research Center of Pediatric Infectious Diseases, Institute of Immunology and Infectious Diseases, Iran University of Medical Sciences, Tehran, Iran.
Eye Research Center, the five Senses Institute, Iran University of Medical Sciences, Tehran, Iran.
Trans R Soc Trop Med Hyg. 2021 Dec 2;115(12):1389-1395. doi: 10.1093/trstmh/trab062.
Toxoplasmic chorioretinitis may occur as a result of acquired toxoplasmosis or reactivated congenital toxoplasmosis. In this study, Toxoplasma gondii bradyzoite genes along with the B1 gene were evaluated to detect T. gondii DNA in serum and peripheral blood mononuclear cells (PBMCs) of patients with toxoplasmic chorioretinitis.
Blood samples were collected from 10 patients (7 cases of active chorioretinal lesions and 3 cases of old chorioretinal scars). The genomic DNA was extracted from the patients' serum and PBMCs and a polymerase chain reaction (PCR) assay was performed using bradyzoite genes along with B1. The subjects were also evaluated in terms of the T. gondii antibodies.
The PCR results were positive in four of seven patients (57.1%) with active ocular toxoplasmosis lesions. In three patients (42.8%), the PCR results were positive for MAG-1 and SAG-4 and in one patient (14.3%) the PCR results were only positive for the B1 gene. The PCR results were positive only in the PBMCs, whereas they were negative in the serum samples. Two patients with positive PCR results showed high Toxoplasma immunoglobulin G (IgG) antibody titres. However, none of the patients showed positive Toxoplasma IgM antibodies.
The PBMCs are suitable for evaluating toxoplasmic chorioretinitis. The present results showed that PCR with bradyzoite genes is useful in the diagnosis of toxoplasmic chorioretinitis in PBMCs.
弓形体性脉络膜视网膜炎可由获得性弓形体病或再激活先天性弓形体病引起。在这项研究中，评估了刚地弓形虫缓殖子基因和 B1 基因，以检测患有弓形体性脉络膜视网膜炎的患者血清和外周血单核细胞（PBMC）中的弓形虫 DNA。
从 10 名患者（7 例活动性脉络膜视网膜病变和 3 例陈旧性脉络膜视网膜瘢痕）中采集血样。从患者的血清和 PBMC 中提取基因组 DNA，并使用缓殖子基因和 B1 进行聚合酶链反应（PCR）检测。还评估了这些患者的弓形虫抗体。
在活动性眼弓形体病病变的 7 例患者中，有 4 例（57.1%）PCR 结果为阳性。在 3 例患者（42.8%）中，MAG-1 和 SAG-4 的 PCR 结果为阳性，在 1 例患者（14.3%）中，仅 B1 基因的 PCR 结果为阳性。PCR 结果仅在 PBMC 中阳性，而在血清样本中为阴性。2 例 PCR 结果阳性的患者表现出高弓形虫免疫球蛋白 G（IgG）抗体滴度。但是，没有患者显示出阳性的弓形虫 IgM 抗体。
PBMC 适合评估弓形体性脉络膜视网膜炎。本研究结果表明，用缓殖子基因进行 PCR 有助于诊断 PBMC 中的弓形体性脉络膜视网膜炎。
