Discordant Phenotypes of Nephritis in Patients with X-linked Agammaglobulinemia.

PURPOSE: To define the clinical and histological characteristics of nephritis in patients with X-linked agammaglobulinemia (XLA) and their immunological profiles. METHODS: The clinical, immunological, and histological findings of nine patients with XLA and nephritis were retrospectively analyzed. RESULTS: Based on kidney histological findings, patients with XLA and nephritis could be divided into two groups, viz., chronic glomerulonephritis (CGN) and tubulointerstitial nephritis (TIN). The two groups showed different immunological profiles. Patients in the CGN group exhibited an atypical immunological profile of XLA, with pathogenic leaky B cells producing immunoglobulins that may play a role in forming immune complexes and causing immune-mediated glomerulonephritis. In contrast, patients in the TIN group exhibited a typical immunological profile of XLA, suggesting that antibody-independent/other BTK-dependent mechanisms, or immunoglobulin replacement therapy (IgRT)-related immune/nonimmune-mediated nephrotoxicity causes TIN. CONCLUSION: Nephritis occurring in patients with XLA could have links between their renal pathology and immunological status. Careful observation is recommended to detect kidney pathology in patients with XLA on IgRT.

Predicting Long-Term Ventricular Arrhythmia Risk in Children with Acute Lymphoblastic Leukemia Using Normal Values of Ventricular Repolarization Markers Established from Japanese Cohort Study.

BACKGROUND: Cardiac complications due to anthracycline treatment may become evident several years after chemotherapy and are recognized as a serious cause of morbidity and mortality in cancer patients or childhood cancer survivors. OBJECTIVES: We analyzed ventricular repolarization parameters in electrocardiography for pediatric acute lymphoblastic leukemia patients during chemotherapy and in long-term follow-up. To establish the reference values of ventricular repolarization parameters in children, we retrospectively summarized the Tpe interval, QT interval, QTc interval, and Tpe/QT ratio in healthy Japanese children. METHODS: Electrocardiography data recorded from students in 1st and 7th grades were randomly selected from a database maintained by the school-based screening system in the Oita city cohort, Japan. Subsequently, chronological data of the Tpe/QT ratio in 17 pediatric patients with acute lymphoblastic leukemia were analyzed over time. RESULTS: The mean ± standard deviation of the Tpe interval in 1st and 7th graders was 70 ± 7 and 78 ± 17 ms, respectively, while the mean ± standard deviation of the Tpe/QT ratio was 0.21 ± 0.02 and 0.22 ± 0.02 ms, respectively. During the intensive phase of treatment, the Tpe/QT ratios of 3 high-risk patients among the 17 patients with acute lymphoblastic leukemia exceeded the upper limit. CONCLUSION: The Tpe/QT ratio has a potential clinical application in predicting the risk of long-term ventricular arrhythmia of cancer patients or childhood cancer survivors from childhood to adulthood.

Vitamin D deficiency associated with dilated cardiomyopathy in early infancy caused by maternal cholestasis.

Breast feeding is known to be a major cause of vitamin D deficiency in infants because the content of vitamin D in breast milk is significantly lower than that in formula. We report a case of a 1-mo-old boy who developed hypocalcemic seizures and dilated cardiomyopathy caused by vitamin D deficiency despite being fed a sufficient amount of regular formula. The cause of vitamin D deficiency in this case was maternal vitamin deficiency due to severe hyperemesis and insufficient sunlight exposure, induced mainly by the malabsorption of fat-soluble vitamins caused by maternal cholestasis. We should carefully consider maternal conditions during pregnancy and the postpartum period to detect and prevent vitamin D deficiency in the fetus and infant.

Cell distribution differences of matrix metalloproteinase-9 and tissue inhibitor of matrix metalloproteinase-1 in patients with Kawasaki disease.

The interaction of matrix metalloproteinase (MMP)-9 and tissue inhibitor of matrix metalloproteinase-1 has been implicated in the formation of coronary aneurysms in Kawasaki disease. MMP-9 and tissue inhibitor of matrix metalloproteinase-1 were distributed predominantly in the granulocytes and platelets, respectively, in patients with Kawasaki disease. The plasma values of MMP-9 correlated positively with the circulating neutrophil count. Inhibiting the activity of granulocytes and maintaining the platelet activity might prevent coronary aneurysms.

Detection of platelet-binding anti-measles and anti-rubella virus IgG antibodies in infants with vaccine-induced thrombocytopenic purpura.

A 15-month-old infant presented with thrombocytopenic purpura after sequential administration of measles-rubella combined vaccine, varicella vaccine and mumps vaccine every 4 weeks. Her thrombocytopenia persisted for more than 12 months. Both anti-measles and anti-rubella virus IgG antibodies were detected in the patient's-isolated platelets on day 154 of illness, which were not detected when there was a reduction of the serum IgG antibody titers on days 298 and 373 of illness, respectively.We also detected the isolated platelet-binding anti-measles and anti-rubella virus IgG antibodies in two other pediatric patients. This is the first report demonstrating direct evidence of vaccine-induced thrombocytopenic purpura.