This study aimed to investigate the characteristics of COVID-19-associated multisystem inflammatory syndrome in children (MIS-C) and Kawasaki disease shock syndrome (KDSS) and to compare the similarities and differences between the two diseases. The incidence of KDSS and MIS-C was also estimated. Medical records of patients diagnosed with MIS-C or KDSS at four hospitals from January 2013 to December 2022 were retrospectively reviewed. Thirty-one patients were enrolled in the study in either an MIS-C group (n = 22) or a KDSS group (n = 9). The incidence of KDSS in KD was 0.8% (9/1095) and the incidence of MIS-C versus KD was 10.2% (22/216). Compared with the MIS-C group, the KDSS group had longer hospital stays and more severe systemic inflammation (e.g., anemia, elevated C-reactive protein, hypoalbuminemia, and pyuria) and organ dysfunction (e.g., number of involved organs, shock, vasoactive infusion, and intensive care unit admission). All patients in the MIS-C group, but none in the KDSS group, including two patients during the COVID-19 pandemic, had laboratory evidence of SARS-CoV-2 infection. MIS-C and KDSS shared demographic, clinical, and laboratory characteristics; organ dysfunction; treatment; and outcomes. Overall severity was more severe in patients with KDSS than in those with MIS-C. The most important difference between MIS-C and KDSS was whether SARS-CoV-2 was identified as an infectious trigger.

Recognition of macrophage activation syndrome (MAS) in patients with refractory Kawasaki disease (KD) can be challenging. This study aimed to investigate the incidence of MAS in patients with refractory KD and to compare the characteristics of refractory KD and MAS. Medical records of 468 patients diagnosed with KD from January 2010 to December 2019 were retrospectively reviewed. Of the 468 KD patients, 63 were enrolled in the study as a refractory KD group (n = 59) and an MAS group (n = 4). The incidence of MAS was 0.8% (4/468) in patients with KD and 6.3% (4/63) in patients with refractory KD. Compared to the refractory KD group, the MAS group had higher frequencies of incomplete KD, hepatosplenomegaly, third-line treatment, and MAS screening, and showed lower levels of albumin. No significant differences were found in other clinical and laboratory findings. In addition to four patients with MAS, five patients with refractory KD who received third-line treatment showed severe systemic inflammation and organ dysfunction, but only one in five patients underwent MAS screening, including ferritin levels. In conclusion, given the relatively high incidence of MAS in children with refractory KD and the similar phenotype between refractory KD and MAS, we propose that MAS screening should be included in routine laboratory tests for refractory KD.

In the present study, the results of brain magnetic resonance imaging (MRI) in girls with central precocious puberty (CPP) were compared those in with girls evaluated for headaches. A total of 295 girls with CPP who underwent sellar MRI were enrolled. A total of 205 age-matched girls with chronic or recurrent headaches without neurological abnormality who had brain MRI were included as controls. The positive MRI findings were categorized as incidental non-hypothalamic–pituitary (H–P), incidental H–P, or pathological. Positive MRI findings were observed in 39 girls (13.2%) with CPP; 8 (2.7%) were classified as incidental non-H–P lesions, 30 (10.2%) as incidental H–P lesions, and 1 (0.3%) as a pathological lesion (tuber cinereum hamartoma). The prevalence of positive MRI findings in girls with CPP did not differ from girls with headaches (13.2% vs. 12.2%, p = 0.74). The prevalence of incidental H–P lesions in girls with CPP <6 years of age, 6–6.9 years of age, and 7–7.9 years of age was 21.2%, 13.5%, and 9.6%, respectively (p = 0.21). Known pathological lesions were detected in only one (3.0%) girl with CPP aged <6 years and in no girls with CPP aged 6–7.9 years. Microadenomas were detected in no girls with CPP aged <6 years and in 5 (1.9%) girls with CPP aged of 6–7.9 years. Our findings call into question the routine use of brain MRI in girls with CPP, especially in girls 6 years or older. Current guidelines recommend a follow-up MRI in cases of microadenoma, but few data exist to support this recommendation for children.

Diabetic nephropathy (DN) is a serious microvascular complication in childhood diabetes and microalbuminuria has been a solid indicator in the assessment of DN. Nevertheless, renal injury may still occur in the presence of normoalbuminuria (NA) and various tubular injury biomarkers have been proposed to assess such damage. This case-controlled study aimed to evaluate plasma and urinary neutrophil gelatinase-associated lipocalin and kidney injury molecule-1 (KIM-1) levels in diabetic children particularly in those with normo- and high-NA stages and determine their role in predicting DN. Fifty-four children/adolescents with type 1 and 2 diabetes and forty-four controls aged 7–18 years were included. The baseline clinical and laboratory characteristics including plasma and urinary biomarkers were compared. The plasma KIM-1 levels were significantly higher in diabetic children than in the controls and in high-NA children than normo-NA children. Glycosylated hemoglobin (HbA1c) was identified as a significant risk factor for increased plasma KIM-1. The optimal cutoff for HbA1c when the plasma KIM-1 was > 23.10 pg/mL was 6.75% with an area under the curve of 0.77. For diabetic children with mildly increased albuminuria, the plasma KIM-1 complementary to MA may help increase the yield of detecting DN. Our findings also suggested an HbA1c cutoff of 6.75% correlated with increased plasma KIM-1.

Background/Objective: With increasing cases of osteoporosis in children and adolescents, the need for timely diagnosis, management, and follow-up has become important. This study aimed to determine whether bone turnover markers (BTMs), particularly serum bone-specific alkaline phosphatase (BsALP) and serum C-telopeptide of collagen type 1 (CTx), accurately reflect BMD. Methods: In this retrospective study, 280 post-puberty males and females who were previously diagnosed with hemato-oncologic, rheumatic, gastrointestinal, and endocrinologic diseases at a single tertiary care center were reviewed. The association between the lumbar spine bone mineral density (LSBMD) Z-scores and BTMs, such as BsALP and CTx, were assessed. The LSBMD was measured in the anterior–posterior direction using DXA, and BTMs were determined using the blood samples obtained. Results: Of the 280 patients, 95 were male (33.9%), and the mean age was 15.4 $\pm$ 2.07 years. With multivariate regression analysis, LSBMD Z-scores and BsALP showed a negative correlation with p < 0.007, while CTx was not statistically significant. The logistic regression models showed that after adjusting for underlying diseases and sex, as BsALP increased, the probability of LSBMD Z-score being ≤−2 increased with an odds ratio of 1.043 (p = 0.048). When comparing BTMs with vertebral fracture while adjusting for underlying diseases and sex, as BsALP increased, the probability of vertebral fracture increased with an odds ratio of 1.035 (p = 0.005). Conclusions: The positive correlation between BsALP and LSBMD Z-scores being ≤−2, as well as with vertebral fracture after adjusting for underlying diseases and sex, suggests the possible application of BsALP as a predictor of bone health in patients.

This study aimed to investigate the impact of hypogonadism on bone mineral density (BMD) in children and adolescents with chronic diseases to determine the relationship between sex hormones and BMD. This retrospective study included 672 children and adolescents with chronic diseases such as hemato-oncologic, rheumatoid, gastrointestinal, and endocrinologic diseases. The relationship between the sex- and Tanner-stage-matched Z-scores for sex hormones and the sex- and age-matched lumbar spine BMD (LSBMD) Z-scores was evaluated. Adjustments were made for confounders such as underlying diseases, age at diagnosis, and age- and sex-matched body mass index Z-scores. Patients had a mean LSBMD Z-score of −0.55 ± 1.31. In the multivariate regression analysis, male testosterone showed a positive association with the LSBMD Z-score (p < 0.001), whereas female estradiol, luteinizing hormone, and follicular-stimulating hormone showed no significant association with the LSBMD Z-scores. In the male group, the testosterone level was associated with LSBMD Z-scores > −1.0 (p < 0.001), > −2.0 (p < 0.001), and > −3.0 (p = 0.002), while the estradiol level was associated with LSBMD Z-scores > −2.0 (p = 0.001) and > −3.0 (p = 0.002) in the female group. In conclusion, sex hormones are associated with BMD in children and adolescents with chronic diseases. Therefore, various measures may be necessary to predict future skeletal problems and improve bone health in these patients.