Stagno S, Pifer L L, Hughes W T, Brasfield D M, Tiller R E
Pediatrics. 1980 Jul;66(1):56-62.
Of 67 infants enrolled in a prospective study of infant pneumonia ten (14%) had evidence of Pneumocystis carinii infection. Diagnosis was achieved by demonstrating circulating P carinii antigens by counterimmunoelectrophoresis in all ten cases and by histopathology in the only infant who underwent an open lung biopsy. Antigenemia did not occur in 64 control infants (P = .003), nor in 57 patients of similar age who were hospitalized with pneumonitis due to Chlamydia trachomatis, respiratory syncytial virus, cytomegalovirus, adenovirus, and influenza A and influenza B viruses. None of the ten infants with P carinii pneumonitis had evidence of a primary immunodeficiency nor had any received immunosuppressive medication. These patients were hospitalized at a mean age of 6 weeks (range 2 to 12) and their illness was characterized by its afebrile course, presentation in crisis with severe respiratory distress, apnea, tachypnea, cough, increased IgM, and bilateral pulmonary infiltrates with hyperaeration. The clinical features of P carinii pneumonitis were indistinguishable from those of C trachomatis and cytomegalovirus pneumonia. Treatment with trimethoprim-sulfamethoxazole was associated wtih rapid disappearance of circulating antigens; however, the small number of patients studied did not permit an analysis of its clinical efficacy. These results indicate that P carinii singly or in combination with other infectious agents may be an important cause of pneumonitis in young, immunocompetent infants with no underlying illnesses.
在一项关于婴儿肺炎的前瞻性研究中，67名婴儿中有10名（14%）有卡氏肺孢子虫感染的证据。所有10例均通过对流免疫电泳检测循环中的卡氏肺孢子虫抗原确诊，仅1例接受开胸肺活检的婴儿通过组织病理学确诊。64名对照婴儿未出现抗原血症（P = 0.003），57名因沙眼衣原体、呼吸道合胞病毒、巨细胞病毒、腺病毒以及甲型和乙型流感病毒引起肺炎而住院的同龄患者也未出现抗原血症。10例患有卡氏肺孢子虫肺炎的婴儿均无原发性免疫缺陷的证据，也均未接受过免疫抑制药物治疗。这些患者住院时的平均年龄为六周（范围2至12周），其病情特点为无发热过程，起病时出现严重呼吸窘迫、呼吸暂停、呼吸急促、咳嗽、IgM升高以及伴有肺过度充气的双侧肺部浸润。卡氏肺孢子虫肺炎的临床特征与沙眼衣原体和巨细胞病毒肺炎难以区分。用甲氧苄啶 - 磺胺甲恶唑治疗后循环抗原迅速消失；然而，由于研究的患者数量较少，无法分析其临床疗效。这些结果表明，卡氏肺孢子虫单独或与其他感染因子一起，可能是无基础疾病的免疫功能正常的幼儿肺炎的重要病因。
