Kaga Akimune, Watanabe Hiroshi, Miyabayashi Hiroki, Metoki Takaya, Kitaoka Setsuko, Kumaki Satoru
Department of Pediatrics, National Hospital Organization Sendai Medical Center.
Tohoku J Exp Med. 2016 Oct;240(2):167-170. doi: 10.1620/tjem.240.167.
Neonatal toxic shock syndrome-like exanthematous disease (NTED) is a newly recognized neonatal infectious disease, caused by the superantigen toxic shock syndrome toxin-1 (TSST-1). TSST-1 is mainly produced by methicillin-resistant Staphylococcus aureus, and the immune responses to TSST-1 are known to cause toxic shock syndrome, a life-threatening infectious disease. The clinical symptoms of NTED are skin rash, fever, and thrombocytopenia, but severe thrombocytopenia is rare in term infants with NTED. Although the cause of NTED is the same as that of toxic shock syndrome, the clinical symptoms of NTED are milder than toxic shock syndrome. The mild phenotype of NTED has been explained by selectively elevated serum levels of anti-inflammatory cytokine interleukin (IL)-10, which suppress immune responses to TSST-1. In the present study, we report a term female infant of NTED complicated with hemophagocytic syndrome (HPS). HPS is characterized by systemic inflammation and hemophagocytosis, caused by uncontrolled activation of T cells and macrophages. The serum IL-10 level of the patient at 4 days of age was relatively low (67 pg/mL) for NTED but still higher than normal controls (< 2.0 pg/mL). The patient also showed severe thrombocytopenia. We speculate that the serum IL-10 level of the patient was enough to supress immune responses to TSST-1, thereby resulting in NTED, but not enough to suppress the onset of HPS. This is the first reported case of NTED complicated with HPS. If a physician encounters an NTED patient with severe cytopenia, microscopic examination of peripheral blood smear should be carried out to exclude HPS.
新生儿中毒性休克综合征样皮疹病（NTED）是一种新发现的新生儿传染病，由超抗原中毒性休克综合征毒素-1（TSST-1）引起。TSST-1主要由耐甲氧西林金黄色葡萄球菌产生，已知对TSST-1的免疫反应会导致中毒性休克综合征，这是一种危及生命的传染病。NTED的临床症状为皮疹、发热和血小板减少，但足月患NTED的婴儿中严重血小板减少较为罕见。尽管NTED的病因与中毒性休克综合征相同，但其临床症状比中毒性休克综合征更为轻微。NTED的轻度表型已通过血清中抗炎细胞因子白细胞介素（IL）-10水平的选择性升高来解释，IL-10可抑制对TSST-1的免疫反应。在本研究中，我们报告了一名患NTED并并发噬血细胞综合征（HPS）的足月女婴。HPS的特征为全身炎症和噬血细胞现象，由T细胞和巨噬细胞的失控激活引起。该患者4日龄时血清IL-10水平对于NTED来说相对较低（67 pg/mL），但仍高于正常对照（<2.0 pg/mL）。该患者还出现了严重的血小板减少。我们推测，患者的血清IL-10水平足以抑制对TSST-1的免疫反应，从而导致NTED，但不足以抑制HPS的发病。这是首例报道的NTED并发HPS的病例。如果医生遇到患有严重血细胞减少的NTED患者，应进行外周血涂片显微镜检查以排除HPS。
