Assessment of a Rapid Antigen Detection Kit for Diagnosis of Mycoplasma pneumoniae in Pediatric Community-Acquired Pneumonia / 日本農村医学会雑誌

RibotestMycoplasma (Ribotest™), a rapid antigen detection assay for ribosomal protein L7/L12 for the diagnosis of Mycoplasma pneumoniae infection, has become available in Japan. However, the clinical utility of Ribotest remains controversial. We enrolled 1,140 children admitted to our hospital between January 2014 and March 2016 due to community-acquired pneumonia. We prospectively obtained two throat swabs during the acute phase; DNA detection using a loop-mediated isothermal amplification (LAMP) assay and antigen detection using Ribotest were performed for each sample. We also collected paired serum samples during the acute and convalescent phases for determining M. pneumoniae antibody titers using the particle agglutination test. M. pneumoniae pneumonia was diagnosed through either a positive LAMP assay or a 4-fold increase in antibody titers. Overall, 237 children (21%) were diagnosed with M. pneumoniae pneumonia. We evaluated the utility of Ribotest both in the non-epidemic period (January 2014–July 2015) and the epidemic period (August 2015–March 2016). Sensitivity of Ribotest for M. pneumoniae pneumonia was 23% in the non-epidemic period and 22% in the epidemic period, respectively. When serology was used as the standard, sensitivity of Ribotest was 25% in the non-epidemic period and 22% in the epidemic period, significantly lower than those of the LAMP assay (80% and 91%, respectively). Ribotest yielded false-positive results in 16 cases in the non-epidemic period and in 6 cases in the epidemic period. Thus, positive predictive values of Ribotest were significantly lower in the non-epidemic period (50%) than in the epidemic period (86%). Multivariate analysis showed that a shorter duration of fever before sampling (OR = 1.7) and a higher incidence of co-infection with other pathogens (OR = 29.4) were observed in children showing false-positive results of Ribotest. Thus, we conclude that Ribotest is unsuitable for rapid diagnosis of pediatric M. pneumoniae pneumonia.

Clinical Features and Treatment Outcome of Childhood Leukemia / 日本農村医学会雑誌

  We reviewed the clinical features and treatment outcome of 110 children with leukemia. Treatment was performed between 1980 and 2009 at our hospital. The mean age at onest was 5 years 6 months, the ratio of males to females was 1:0.72, and mean leukocyte count was 4.91×10⁴/μl. Subtypes of leukemia were acute lymphoblastic leukemia (ALL) in 79.1% of the patients, acute myeloid leukemia (AML) in 17.2%, and chronic leukemia in 3.6%. In all patients, the overall 30-year survival rate estimated by the Kaplan-Meier method was 67.4%. In the three decades from the 1980s, the overall 10-year survival rate has been improved significantly from 46.4% in the 1980s, 69.2% in the 1990s to 87.2% in the 2000s (P<0.01). The overall 10-year survival rate was 70.7% in all children with ALL, and 70.6% in all children with AML. But in the last decade, the 10-year survival rate was improved to 87.0% in children with ALL and 87.3% in children with AML. Twenty-four patients received hematopoietic stem-cell transplantation, and the 10-year survival rate was 58.6% after transplant. Second malignancies were detected in three patients, and six patients have long-term sequelae. In conclusionn, the treatment result of childhood leukemia has improved considerably, so that more intensive treatment for patients with poor prognosis and less toxic treatment for patients with good prognosis will be necessary in future.