Sharma Avinash, Bhattarai Dharmagat, Gupta Anju, Guleria Sandesh, Rawat Amit, Vignesh Pandiarajan, Garg Ravinder, Singh Surjit
Allergy Immunology Unit, Department of Pediatrics, Advanced Pediatrics Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, 160012, India.
Indian J Pediatr. 2021 Dec;88(12):1170-1173. doi: 10.1007/s12098-021-03680-1. Epub 2021 Mar 10.
To study autoantibody profile in juvenile dermatomyositis (JDM) and to look for phenotypic associations of these autoantibodies, if any.
Thirty-four children with JDM with a minimum follow-up duration of 24 mo were enrolled. Clinical findings and investigations at the time of diagnosis were noted from the clinic records. At inclusion, they were clinically evaluated for residual disease, disease activity and complications. All the enrolled patients were tested for antinuclear antibodies (ANA), muscle specific antibodies (MSA) and myositis associated autoantibodies (MAA).
ANA positivity was seen in 14/34 children. At least one MSA or MAA was present in 8/34 children. Anti-SRP, anti-MDA-5, and anti-Mi-2 antibodies were present in 4, 3, and 1 patient, respectively. Anti-SSA/Ro52 antibody was positive in 1 child. All four children with anti-SRP antibody were girls, who had polycyclic course. Two of them developed calcinosis. Prominent skin involvement with less severe muscle involvement and monocyclic course were seen in patients with anti-MDA-5 antibody. Two of them had arthritis/arthralgia at initial presentation. The only patient with anti-Mi-2 had normal muscle strength at enrollment. None of the patients had anti-synthetase antibodies (anti-Jo-1, anti-PL-7, anti-PL-12, anti-EJ), anti-Ku, anti-Scl-70, anti-NXP-2 or anti-HMG CoA.
Eight patients tested positive for at least one MSA or MAA. The prevalence of autoantibodies was low. Positivity for anti-SRP, anti-MDA-5, anti-Mi-2 and anti-SSA/Ro52 antibodies was seen in 4, 3, 1 and 1 patients, respectively. Ethnic differences and testing for autoantibodies during/after therapy could be responsible for the low positivity rate for autoantibodies.
研究青少年皮肌炎（JDM）中的自身抗体谱，并寻找这些自身抗体的表型关联（若存在）。
纳入34例随访时间至少24个月的JDM患儿。从临床记录中记录诊断时的临床表现和检查结果。纳入时，对他们进行残余疾病、疾病活动度和并发症的临床评估。所有纳入患者均检测抗核抗体（ANA）、肌肉特异性抗体（MSA）和肌炎相关自身抗体（MAA）。
14/34例患儿ANA呈阳性。8/34例患儿存在至少一种MSA或MAA。抗信号识别颗粒（SRP）抗体、抗黑色素瘤分化相关蛋白5（MDA-5）抗体和抗Mi-2抗体分别在4例、3例和1例患者中出现。抗SSA/Ro52抗体在1例患儿中呈阳性。所有4例抗SRP抗体阳性患儿均为女孩，病程呈多循环。其中2例出现钙质沉着。抗MDA-5抗体阳性患者表现为明显的皮肤受累且肌肉受累较轻，病程呈单循环。其中2例在初诊时有关节炎/关节痛。唯一1例抗Mi-2抗体阳性患者在纳入时肌力正常。所有患者均无抗合成酶抗体（抗Jo-1、抗PL-7、抗PL-12、抗EJ）、抗Ku、抗Scl-70、抗NXP-2或抗HMG CoA。
8例患者至少一种MSA或MAA检测呈阳性。自身抗体的患病率较低。抗SRP抗体、抗MDA-5抗体、抗Mi-2抗体和抗SSA/Ro52抗体阳性分别见于4例、3例、1例和1例患者。种族差异以及治疗期间/治疗后自身抗体检测可能是自身抗体阳性率低的原因。
