A 9-year-old boy with pallor and macrohematuria showed hemolytic anemia, thrombocytopenia and renal failure. There was no history of diarrhea and the stool culture was negative. A diagnosis of atypical hemolytic uremic syndrome (HUS) was confirmed; however, the cause of the prolonged activated partial thromboplastin time (APTT) was unknown. Plasma exchange and hemodialysis were performed because of progressive hemolytic anemia and renal dysfunction. Fresh frozen plasma was administered frequently to correct the prolonged APTT after hemolysis was controlled and C3 levels had recovered. Factor H (FH) and factor I (IF) levels were normal and we did not detect mutations of FH, IF and membrane cofactor protein. Further investigation revealed the presence of anti-FH antibody in the patient's plasma and a deficiency of coagulation factor XII. Analysis of the patient's coagulation system displayed <3% functional activity of factor XII, whereas levels of other coagulation factors were within the normal range. Two novel mutations (W222G and R447S) were identified upon analysis of the factor XII gene in this patient. Moreover, further investigation revealed that compound heterozygous mutations were present in two of the patient's three siblings, while the third sibling only had a mutation at W222G. The patient was treated for atypical HUS; however, no treatment was required for factor XII deficiency as he did not display a hemorrhagic tendency. We report here a rare case of atypical HUS due to anti-FH antibody presenting with a coagulation factor XII deficiency.

A 2-year treatment with a medium dose of cyclosporine A with or without other immunosuppressive agents is relatively safe with regard to the development of cyclosporine A nephrotoxicity.

Objective: To investigate the usefulness of procalcitonin (PCT) as predictive factors of intravenous immunoglobulin (IVIG)-resistant Kawasaki disease patients. Methods: We retrospectively analyzed the laboratory data from 215 children with Kawasaki disease treated with IVIG from 2014 to 2019. We analyzed the clinical and laboratory parameters just before the IVIG including serum levels of PCT with respect to the IVIG response. Results: Eventually, 127 patients were analyzed. The median age was 2.4 years. IVIG was effective in 108 children (responders) and was ineffective in 19 (non-responders). Serum PCT concentration was higher in non-responders than those of responders (P < 0.001). Multivariate logistic regression analyses indicated that higher PCT concentration (odds ratio 1.34, 95% confidence interval 1.10–1.64) were associated with IVIG resistance. Analyses of the receiver operating characteristic curve showed that the cutoff value of PCT 2.18 ng/mL had 46.4% of sensitivity and 93.9% of specificity. Receiver operating characteristic analysis yielded an area under the curve of 0.82 (0.72–0.92) to predict IVIG resistance. Conclusions: Serum PCT value can be an excellent biomarker for predicting unresponsiveness to IVIG with a good discriminatory ability as well as the existing prediction scores.

We evaluated the diagnostic accuracy of insulin-like growth factor-1 (IGF-1) for screening growth hormone deficiency (GHD) to determine the usefulness of IGF-1 as a screening test. Among 298 consecutive children who had short stature or decreased height velocity, we measured IGF-1 levels and performed growth hormone (GH) secretion test using clonidine, arginine, and, in cases with different results of the two tests, L-dopa. Patients with congenital abnormalities were excluded. GHD was defined as peak GH ≤ 6.0 ng/mL in the two tests. We identified 60 and 238 patients with and without GHD, respectively. The mean IGF-1 standard deviation (SD) was not significantly different between the GHD and non-GHD groups (p = 0.23). Receiver operating characteristic curve analysis demonstrated the best diagnostic accuracy at an IGF-1 cutoff of − 1.493 SD, with 0.685 sensitivity, 0.417 specificity, 0.25 positive and 0.823 negative predictive values, and 0.517 area under the curve. Correlation analysis revealed that none of the items of patients’ characteristics increased the diagnostic power of IGF-1. IGF-1 level had poor diagnostic accuracy as a screening test for GHD. Therefore, IGF-1 should not be used alone for GHD screening. A predictive biomarker for GHD should be developed in the future.

BackgroundAnti-glomerular basement membrane (GBM) antibody disease is a rare autoimmune disorder characterized by rapidly progressive glomerulonephritis caused by autoantibodies against the α3-chain of type IV collagen in the GBM.Case presentationAn 8-year-old girl with hematuria and proteinuria due to anti-GBM nephritis was diagnosed with hematuria and proteinuria during a school urine screening program. Her blood pressure and serum creatinine levels were normal. Her hematuria and proteinuria persisted for several months. Since a spot urine protein to creatinine ratio was around 7 g/g Cre, a percutaneous renal biopsy was performed. Immnofluorescent staining demonstrated a linear pattern for immunoglobulin G along the entire GBM. Chest computed tomography was normal. Anti-GBM antibody assays were reported as slightly raised; thus, the diagnosis was anti-GBM disease with normal renal function. Treatment included plasma exchange, intravenous high-dose methylprednisolone, and cyclophosphamide as a mainstay medication. The treatment was rapidly effective with an immediate decrease in anti-GBM titers and proteinuria.ConclusionsCases of anti-GBM disease with normal renal function in children are rare. Treatment in children has not been established; therefore, clinicians need to carefully select an effective treatment because the prognosis is poor.