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Panton Valentine Leukocidin (PVL) is one of the many toxins produced by Staphylococcus aureus. In Japan, PVL-positive S. aureus strains are mainly methicillin-resistant S. aureus (MRSA). Data regarding PVL-positive methicillin-sensitive S. aureus (MSSA) are scarce. In this report, we describe a case of severe infection by PVL-positive MSSA. A 12-year-old healthy girl was admitted with high fever and pain in the lower back. Computed tomography revealed a diagnosis of psoitis and multiple venous thromboses. Blood cultures obtained after admission revealed infection with MSSA. Her fever continued despite adequate antibiotic therapy. On the fifth hospitalization day, she developed bladder dysfunction, and an abscess was noted near the third lumbar vertebra. She underwent an emergency operation and recovered. Bacterial analyses revealed that the causative MSSA was a PVL-producing single variant of ST8 (related to USA300clone), of sequence type 2149. PVL is known to cause platelet activation. This case demonstrates the need for detailed analyses of the causative strain of bacteria in cases of S. aureus infection with deep vein thrombosis, even in cases of known MSSA infection.

Detecting Pneumocystis jirovecii by bronchoalveolar lavage or lung biopsy is the gold standard for diagnosis of P. jirovecii pneumonia (PJP); however, these techniques are not always applicable in children because of their high invasiveness. We report two pediatric cases of PJP diagnosed by polymerase chain reaction (PCR) of gastric lavage that were successfully treated. To date, there are no reported cases of using PCR of gastric lavage to diagnose PJP. On the day of PJP onset, both the infants required respiratory support and infiltrative shadows were observed in both lung fields on chest radiography. Furthermore, their (1 → 3)-β-D glucan levels were elevated. P. jirovecii was detected by PCR of gastric lavage and trimethoprim-sulfamethoxazole was administered for 3 weeks, following which their condition improved. They were long-term steroid users, but without any prophylaxis. PCR of gastric lavage in cases of suspected PJP may help in confirming the diagnosis in children who have mild to moderate airway symptoms, or have difficulty with invasive examination like bronchoscopy.

下降性壊死性縦隔炎(descending necrotizing mediastinitis;DNM)は健常小児には稀な疾患であるが、今回、外傷・手術歴のない健常小児に発症した黄色ブドウ球菌によるDNM11ヵ月女児例を経験した。発熱5日目、意識障害で当院に入院となり、造影CTで咽頭後間隙から上縦隔・後縦隔、左胸腔に低吸収域を認めた。計5回の開胸デブリードマンと約1ヵ月の抗菌薬投与によって後遺症なく軽快した。前医の咽頭培養、血液培養、当院入院時の左胸腔穿刺液培養、手術時の組織培養からメチシリン感受性黄色ブドウ球菌が検出され、Panton-Valentine leucocidin遺伝子が陽性だった。患児の基礎免疫は正常範囲内であり、原発性免疫不全症は否定的だった。重症感染症罹患時は、患者側の因子と菌側の因子双方から原因を精査することが大切である。(著者抄録)

BACKGROUND: There is still no definite treatment for refractory Kawasaki disease (KD). In this pilot study, we evaluated the safety and efficacy of a new protocol consisting of sivelestat sodium hydrate (SSH) combined with additional i.v. immunoglobulin (IVIG) for KD resistant to initial IVIG therapy. METHODS: This study is a prospective non-randomized, open-label and single-arm study undertaken in a population of refractory KD patients at Chiba University Hospital from December 2006 to March 2016. The subjects had KD resistant to initial IVIG (2 g/kg) and received SSH (0.2 mg/kg/h for 5 days) combined with additional IVIG (2 g/kg) as a second-line therapy. We evaluated the safety and efficacy of the treatment during the study period. RESULTS: Forty-six KD patients were enrolled in this study and no serious adverse event was noted. Of these, 45 patients were evaluated for the incidence of coronary artery lesions, which occurred in one patient (2.2%; 95% CI: 0.5-15.2). Twenty-eight (62.2%) responded promptly and were afebrile after the therapy. The median total duration of fever was 8 days (range, 6-28 days). CONCLUSIONS: Additional IVIG combined with SSH as a second-line therapy for KD refractory to initial IVIG therapy was safe and well tolerated and could be a promising option for severe KD. Further investigations are expected to clarify the safety and timing of SSH treatment for KD.

The patient was a 10-month-old boy. He put his father’s smartphone in his mouth, and immediately after it was taken away, hoarseness, wheezing, and retractive breathing developed. On admission, the patient presented with tachypnea and labored breathing. Respiratory sounds were bilaterally weak, and expiratory stridor was noted. A medical interview to the parents revealed no suspicion that foreign body aspiration occurred. Chest and neck X-ray images revealed an asymmetric radiolucent tracheal image of the lower part of the glottis, and there was no abnormality in the lung field and mediastinum. Cervical CT revealed a membrane-like structure with a length of 10 mm and a thickness of 1 mm in the same site, and the patient was transferred to an advanced hospital due to a suspected tracheal foreign body. After transferred to the hospital, labored respiration disappeared and respiratory sound improved. On the same day, removal of the tracheal foreign body was performed under general anesthesia. After induction of anesthesia, ventilation with a bag mask became difficult, causing circulatory failure. Therefore, the rapid response system was initiated, and chest compressions had to be performed for several minutes. The foreign body was incarcerated in the part of the glottis in a form that completely obstructed the airway, and once a side of the foreign body was pushed with the bronchoscope, a slight gap was formed making ventilation possible and stabilizing the condition of the patient. The removed foreign body was a fragment of the plastic case of his father's smartphone. Extubation was performed on the forth days of admission, and an inhospital family support team intervened the family during hospitalization. The patient was discharged on the 12th days of admission without any residual disability. As in the present case, pediatric airway foreign body is a potentially fatal emergency condition. Early diagnosis, treatment, and prevention are important. Unfortunately, there are still a certain number of cases of mortality annually, so continued education for healthcare providers and legal guardians is necessary.

症例は10ヵ月男児。自宅で父親のスマートフォンをくわえていて、取り上げられた直後から嗄声、喘鳴、陥没呼吸が出現した。来院時多呼吸、努力呼吸を認め、呼吸音は両側減弱し狭窄音を聴取した。両親への問診では異物吸引を疑われる状況はないとのことであった。胸部および頸部単純X線で声門下部に気管透亮像の左右差を認め、肺野、縦隔に異常はなかった。頸部CTで同部位に長さ10mm、厚さ1mmの膜様構造物を認め、気管異物疑いで高次搬送した。転院直後努力呼吸は消失し呼吸音も改善を認めていた。同日全身麻酔下に気管異物摘出術を施行した。全身麻酔導入後、バッグマスクおよび声門上器具による換気が困難となり、循環不全を来しRapid Response Systemを発動、数分間の胸骨圧迫を要した。異物が気道を完全閉塞する形で声門部に嵌頓しており、気管支鏡で一旦異物の片側を押し込むことで僅かな隙間ができ換気可能となり、状態は安定化した。摘出異物は父親のスマートフォンのプラスチック製ケースの破片であった。入院4病日に抜管、入院中に院内家族支援チームの介入を行い、12病日に臨床的後遺症なく退院となった。小児気道異物は本症例のように生命に関わる緊急疾患であり、早期診断治療と何よりも予防が重要であるが、依然として毎年一定数の死亡者が存在しており、医療者、保護者への継続的な啓発が必要である。(著者抄録)

4歳男児。発熱や皮膚粘膜症状から川崎病(KD)と診断し、ガンマグロブリン療法(intravenous immunoglobulin:IVIG)を2回施行したが不応であり、プレドニゾロン(prednisolone:PSL)を投与し解熱した。15日間かけてPSLを漸減中止したところ、中止翌日に再発熱し、血球減少とフェリチン上昇を認めた。マクロファージ活性化症候群(Macrophage activation syndrome:MAS)と診断し、ステロイドパルス療法にて病態は改善した。サイトカインプロファイル解析で、病初期からのInterleukin-18(IL-18)高値が判明し、全身型若年性特発性関節炎(Systemic juvenile idiopathic arthritis:sJIA)の合併と推測した。PSL投与による全身症状の改善と炎症反応の正常化を指標に、IL-18関連の炎症が残存する状態でPSLを中止したことで、MASとして再燃したと考え得る経過であった。サイトカインプロファイル解析は、診断基準を満たさないsJIAの診療において、病態把握や薬剤調整の一助となることが示唆された。(著者抄録)

IgA secretion at mucosal sites is important for host defence against pathogens as well as maintaining the symbiosis with microorganisms present in the small intestine that affect IgA production. In the present study, we tested the ability of 5 strains of lactic acid bacteria stimulating IgA production, being Pediococcus acidilactici K15 selected as the most effective on inducing this protective immunoglobulin. We found that this response was mainly induced via IL-10, as efficiently as IL-6, secreted by K15-stimulated dendritic cells. Furthermore, bacterial RNA was largely responsible for the induction of these cytokines double-stranded RNA was a major causative molecule for IL-6 production whereas single-stranded RNA was critical factor for IL-10 production. In a randomized, double-blind, placebo-controlled clinical trial, ingestion of K15 significantly increased the secretory IgA (sIgA) concentration in saliva compared with the basal level observed before this intervention. These results indicate that functional lactic acid bacteria induce IL-6 and IL-10 production by dendritic cells, which contribute to upregulating the sIgA concentration at mucosal sites in humans.

壊疽性膿皮症は、下肢中心の小膿疱や丘疹で発症し、急速に潰瘍を形成する無菌性膿皮症であり、炎症性腸疾患や血管炎などに合併することが多い。症例は2歳女児。発熱と咽頭発赤が1週間持続した後、間歇的腹痛と下腿の膿痂疹が出現、抗菌薬投与を行うも3cm大の潰瘍を形成したため、第18病日に当院へ転院となった。潰瘍は創洗浄と軟膏処置で速やかに上皮化し、壊疽性膿皮症としては非典型的であった。点滴刺入部や手指、口唇に無菌性膿瘍が出現した。HLA-A26/B51/B54は陰性、眼症状は認めず、皮膚病理所見からSweet症候群と診断した。prednisolone(PSL)投与開始後、速やかに解熱し腹痛や皮膚症状の改善を得た。PSL減量中に発熱、腹痛、皮膚粘膜症状の増悪を認め、消化管内視鏡検査で結腸広域に多発潰瘍がみられ、腸管ベーチェット病と診断した。ベーチェット病・Sweet症候群・壊疽性膿皮症は臨床症状が重視するため、診断後も症状の変化に注意し、診断・治療の見直しや合併症の検索を行うことが重要である。(著者抄録)