Ponda Punita, Schuval Susan J, Kaplan Blanka, Logalbo Peter, Roberts Joseph L, Bonagura Vincent R
Division of Allergy and Immunology, Department of Pediatrics, Schneider Children's Hospital, North Shore Long Island Jewish Health System, Great Neck, New York 11021, USA.
Ann Allergy Asthma Immunol. 2006 Dec;97(6):755-8. doi: 10.1016/S1081-1206(10)60965-9.
Severe combined immunodeficiency (SCID) is a rare primary immunodeficiency characterized by abnormal lymphocyte development and lymphopenia. It often presents during the first year of life with recurrent, opportunistic infections, failure to thrive, and malabsorption.
To advocate newborn screening for SCID.
We reviewed the case histories of dizygotic twins with Pneumocystis carinii pneumonia (PCP) at the age of 6 months.
Full-term fraternal twin girls were born to nonconsanguineous parents. Twin A developed recurrent oral candidiasis at 2 months, followed by pneumococcal bacteremia and PCP. At 5 months she had failure to thrive, but her absolute lymphocyte count was normal (5,887 cells/mm3). Subsequently, twin B presented with acute respiratory distress and was also diagnosed as having PCP; her absolute lymphocyte count was 5,852 cells/mm3. Flow cytometric analysis of peripheral blood lymphocytes from both girls demonstrated a T-B+NK+ phenotype consistent with interleukin 7 receptor alpha-chain-mutation SCID. Both girls received a haploidentical T-cell-depleted bone marrow transplant from their mother. In the interim, a homozygous point mutation in the interleukin 7 receptor alpha-chain gene was identified in twin B. Both parents were found to be carriers. Twin A died of chronic lung disease 8 months after transplantation; twin B is currently thriving.
Early diagnosis and treatment of SCID are associated with an increased rate of survival and improved long-term outcome. Some patients with SCID can present without lymphopenia. Thus, we advocate that more sensitive screening tests be considered for inclusion in the newborn screening program currently used in most states.
重症联合免疫缺陷（SCID）是一种罕见的原发性免疫缺陷，其特征为淋巴细胞发育异常和淋巴细胞减少。它常在生命的第一年出现，伴有反复的机会性感染、生长发育迟缓及吸收不良。
提倡对SCID进行新生儿筛查。
我们回顾了一对6个月大患卡氏肺孢子虫肺炎（PCP）的异卵双胞胎的病历。
足月的异卵双胞胎女孩由非近亲父母所生。双胞胎A在2个月时出现反复的口腔念珠菌病，随后发生肺炎球菌菌血症和PCP。5个月时她生长发育迟缓，但绝对淋巴细胞计数正常（5,887个细胞/mm³）。随后，双胞胎B出现急性呼吸窘迫，也被诊断为患有PCP；她的绝对淋巴细胞计数为5,852个细胞/mm³。对两个女孩外周血淋巴细胞的流式细胞术分析显示T-B+NK+表型，与白细胞介素7受体α链突变型SCID一致。两个女孩均接受了来自其母亲的单倍体相合且去除T细胞的骨髓移植。在此期间，在双胞胎B中鉴定出白细胞介素7受体α链基因的纯合点突变。发现父母双方均为携带者。双胞胎A在移植后8个月死于慢性肺病；双胞胎B目前发育良好。
SCID的早期诊断和治疗与生存率提高及长期预后改善相关。一些SCID患者可能没有淋巴细胞减少的表现。因此，我们提倡考虑将更敏感的筛查试验纳入目前大多数州所采用的新生儿筛查项目中。
