Hoyos-Bachiloglu Rodrigo, Rojas Jorge, Borzutzky Arturo, Hernández Pamela, Vinet Ana María, Bustos Paula, Fernández Fabiola, Lagos Macarena, Strickler Alexis, Marinovic María Angélica, Casado Cristina, Poli María Cecilia, King Alejandra
Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Pontificia Universidad Católica de Chile, Santiago, Chile.
Hospital Exequiel González Cortés, Santiago, Chile.
Rev Chil Pediatr. 2020 Dec;91(6):908-916. doi: 10.32641/rchped.vi91i6.2580. Epub 2020 Oct 21.
Severe combined immunodeficiency (SCID) is the most severe form of primary immunodeficiency. To date, there is little local information about this disease.
To describe the epidemiology, complications, prognosis, and use of the BCG vaccine in Chilean patients with SCID.
Retrospective review of the clinical records of patients diagnosed with SCID by clinical immunologists between 1999 and 2020 throughout Chile. SCID was diagnosed according to the cri teria proposed by Shearer: T lymphocytes (CD3+) < 300 cells/μL and proliferation 10% of the limit of normality in response to phytohemagglutinin or presence of T lymphocytes of maternal origin. Data collected from the clinical records were: sex, age at diagnosis, consanguinity, region of origin, lymphocyte subpopulations, genetic diagnosis, infectious and non-infectious complications, BCG vaccination and its complications, age at referral to the bone marrow transplant (BMT) center, and cause of non-BMT-related mortality.
Between 1999 and 2020, 25 patients were diagnosed with SCID. 78% of them were male, mean age at first manifestation of the disease was 2.3 months (0-7), while the mean age at diagnosis was 3.4 months (0-7). 16% of patients had a family history of SCID. 40% of cases were diagnosed within the Metropolitan Region. The most frequent immuno- phenotype was T-B-NK+ SCID (48%). Genetic studies were done in 69.5% of cases, mutations in the RAG2 gene were the most common etiology of SCID (39%). 88% of SCID patients received the Bacillus Calmette-Guerin (BCG) vaccine before diagnosis, including 2 cases with a known family history of SCID. 36% of those who received the vaccine had BCG-related complications. The mean age at referral to a bone marrow transplant center was 7.4 months (5-16). 11/25 patients died before being transferred to a transplant center.
There is a clinically significant delay between the first manifestations and the diagnosis of SCID in Chilean patients, as well as an important time gap between the diagnosis of SCID and referral to a center for BMT. Most SCID cases in Chile receive the BCG vaccine, despite a known family history of the disease, and frequently develop vaccine-related complications.
重症联合免疫缺陷（SCID）是原发性免疫缺陷最严重的形式。迄今为止，关于这种疾病的本地信息很少。
描述智利SCID患者的流行病学、并发症、预后以及卡介苗的使用情况。
对1999年至2020年期间智利各地临床免疫学家诊断为SCID的患者临床记录进行回顾性分析。SCID根据希勒提出的标准进行诊断：T淋巴细胞（CD3+）<300个细胞/μL，对植物血凝素反应的增殖低于正常范围的10%，或存在母源T淋巴细胞。从临床记录中收集的数据包括：性别、诊断时年龄、近亲关系、出生地、淋巴细胞亚群、基因诊断、感染性和非感染性并发症、卡介苗接种及其并发症、转诊至骨髓移植（BMT）中心的年龄以及与BMT无关的死亡原因。
1999年至2020年期间，25例患者被诊断为SCID。其中78%为男性，疾病首次表现的平均年龄为2.3个月（0 - 7个月），而诊断时的平均年龄为3.4个月（0 - 7个月）。16%的患者有SCID家族史。40%的病例在首都大区被诊断。最常见的免疫表型是T - B - NK + SCID（48%）。69.5%的病例进行了基因研究，RAG2基因突变是SCID最常见的病因（39%）。88%的SCID患者在诊断前接种了卡介苗，其中包括2例有已知SCID家族史的病例。接种疫苗的患者中有36%出现了与卡介苗相关的并发症。转诊至骨髓移植中心的平均年龄为7.4个月（5 - 16个月）。25例患者中有11例在转至移植中心之前死亡。
智利患者从疾病首次表现到SCID诊断之间存在临床上显著的延迟，以及SCID诊断与转诊至BMT中心之间存在重要的时间间隔。智利大多数SCID病例尽管有已知的家族病史仍接种了卡介苗，并经常出现与疫苗相关的并发症。
