Zecevic Milica, Minic Aleksandra, Pasic Srdjan, Perovic Vladimir, Prohászka Zoltán
Clinical Immunology and Allergy Department, Institute for Health Protection of Mother and Child of Serbia "Dr Vukan Cupic", Belgrade, Serbia.
Institute of Microbiology and Immunology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
Front Pediatr. 2021 Dec 21;9:756387. doi: 10.3389/fped.2021.756387. eCollection 2021.
Hereditary C1q deficiency is associated with early-onset autoimmunity causing SLE or SLE-like disease as well as increased risk for infections with encapsulated bacteria. It is a rare genetic condition inherited in an autosomal recessive manner, caused by mutations in C1q genes. Treatment and management of this rare disease are very complex and include prophylactic vaccination, antibiotics, and immunosuppressive drugs. There are two possible modalities for the replacement of the missing protein: regular fresh frozen plasma (FFP) administration and allogeneic hematopoietic stem cell transplant because the protein is derived from monocytes. Replacing C1q with FFP is being attempted in some patients with success in controlling the disease and in avoiding flare. We report a case of sixteen-month-old girl with ulcerations in her mouth, skin erythema, and elevated liver enzymes. ANAs were positive, antibodies against dsDNA were negative, but she had positive anti-Smith antibodies. Complement complements C3 and C4 levels were normal. Total complement activity, classical pathway (hemolytic test) was deficient and C1q antigen was below the detection limit supporting the presence of C1q deficiency. The girl has pathogenic homozygous nonsense mutation in C1qC gene, Arg69Ter (c205>T). The initial response to corticosteroid therapy was good. Regular fresh frozen plasma infusions keep her disease under control, and we were able to reduce the dose of corticosteroids. Young patients with cutaneous lesions resembling SLE, early onset of autoimmunity, with normal C3, C4, elevated ANAs, and negative anti-dsDNA, C1q deficiency should be suspected and complement screening tests should be done. It is important to exclude secondary C1q deficiency. FFP in our patient seems to be well tolerated, without any side effects, able to control the disease.
遗传性C1q缺乏症与早发性自身免疫相关，可导致系统性红斑狼疮（SLE）或SLE样疾病，同时增加感染包膜细菌的风险。它是一种罕见的遗传性疾病，以常染色体隐性方式遗传，由C1q基因突变引起。这种罕见疾病的治疗和管理非常复杂，包括预防性疫苗接种、抗生素和免疫抑制药物。对于缺失蛋白的替代有两种可能的方式：定期输注新鲜冷冻血浆（FFP）和异基因造血干细胞移植，因为该蛋白来源于单核细胞。一些患者尝试用FFP替代C1q，在控制疾病和避免病情发作方面取得了成功。我们报告了一例16个月大的女孩，她有口腔溃疡、皮肤红斑和肝酶升高。抗核抗体（ANA）呈阳性，抗双链DNA抗体呈阴性，但她的抗史密斯抗体呈阳性。补体C3和C4水平正常。总补体活性、经典途径（溶血试验）缺乏，C1q抗原低于检测限，支持C1q缺乏的存在。该女孩在C1qC基因中有致病性纯合无义突变，即Arg69Ter（c205>T）。对皮质类固醇治疗的初始反应良好。定期输注新鲜冷冻血浆使她的疾病得到控制，我们能够减少皮质类固醇的剂量。对于有类似SLE皮肤病变、早发性自身免疫、C3和C4正常、ANA升高且抗双链DNA阴性的年轻患者，应怀疑C1q缺乏，并进行补体筛查试验。排除继发性C1q缺乏很重要。我们患者的FFP似乎耐受性良好，没有任何副作用，能够控制疾病。
