金井 孝裕

Glucocorticoids (GCs) are commonly used to treat kidney problems in children and usually work well, but they can sometimes cause bone thinning, which may lead to fractures in the spine. Despite this, there is currently no established clinical approach for managing GC-induced osteoporosis (GIOP) in pediatric patients, highlighting the need for more data. Bone strength reflects both bone mineral density (BMD) and bone quality, with BMD assessed by X-ray and bone quality evaluated through serum or urine bone turnover markers (BTMs). In this case, a seven-year-old girl diagnosed with Henoch-Schönlein purpura nephritis was monitored over a two-year period during steroid treatment. Her BMD and serum BTMs, including alkaline phosphatase (ALP), tartrate-resistant acid phosphatase 5b (TRACP-5b), and undercarboxylated osteocalcin (ucOC), were tracked throughout the course. One month after initiating steroid therapy, her serum ALP (S-ALP) level decreased by 27.1% from baseline, while serum TRACP-5b (S-TRACP-5b) and serum ucOC increased by 34.4% and 52.3%, respectively, although BMD remained unchanged. Two months into treatment, she developed thoracic vertebral fractures (VFs) and was diagnosed with GIOP, prompting the initiation of oral alendronate sodium hydrate. Following the introduction of antiresorptive therapy and a reduction in GC dosage, both S-ALP and S-TRACP-5b levels returned to baseline by six months, accompanied by an 8.8% increase in BMD compared to the one-month level. No further fractures were observed after the cessation of antiresorptive treatment, which was guided by serial monitoring of BMD and BTMs. This case underscores the association of VFs with a decline in bone formation markers and elevations in bone resorption and matrix-related markers and demonstrates how BTMs reflecting bone quality can aid in determining the optimal duration of antiresorptive treatment in pediatric patients with GIOP.

Kidney transplant (KT) requires long-term glucocorticoid (GC) treatment against acute and/or chronic rejection. Glucocorticoid-induced osteoporosis (GIOP) is one of the major concerns in kidney transplant recipients (KTRs). Therefore, it is essential to accumulate GIOP data from paediatric KTRs to aid in their healthy growth. A serial observational study of bone strength was carried out in an 8-year-old girl with bilateral hypoplastic kidney who underwent ABO-compatible living-donor KT and GC treatment over 2 years. Bone strength was evaluated by bone mineral density (BMD) and serum bone turnover markers (BTMs), including serum alkaline phosphatase (S-ALP), serum tartrate-resistant acid phosphatase 5b (S-TRACP-5b), and serum undercarboxylated osteocalcin (S-ucOC). All the levels of BTMs and BMD from 1 M to 4 M remained lower than the levels at 0 months (0 M: baseline). After gradual reduction of GC dose (4 M-24 M), S-ALP levels increased from baseline and S-TRACP-5b levels remained lower than the baseline level, but BMD recovered to baseline and increased. The S-ucOC levels did not increase from baseline. The patient's height growth velocity SDS was +3.99 for 23 months, and no fracture occurred during this observation period. A consistent, predominantly formative state of bone, which maintained higher S-ALP levels and lower S-TRACP-5b levels compared to baseline, could contribute to increased BMD. In addition, no increase in S-ucOC levels from baseline could be associated with no deterioration of bone strength. This case suggests that measurement of BMD and, S-ALP, TRACP-5b and ucOC could be useful for evaluating the trend on bone strength in a paediatric KTR.

In kidney transplant recipients (KTRs), viral infection can lead to antibody and/or T-cell mediated rejection, resulting in kidney transplant dysfunction. Therefore, it is critical to prevent infections. However, KTRs exhibit suboptimal responses to SARS-CoV-2 and/or influenza vaccines, partly due to immunosuppressant therapy. Inter- and intra-individual differences in the biological responses to vaccines may also affect patients' antibody production ability. This study included KTRs who received an messenger RNA SARS-CoV-2 vaccine (3 doses), and an inactivated quadrivalent influenza vaccine (1 or 2 doses). We measured the patients' total antibody titers against SARS-CoV-2 spike antigen, and hemagglutination inhibition (HI) titers against influenza A/H1N1, A/H3N2, B/Yamagata, and B/Victoria. Five patients were eligible for this study. Of these 5 KTRs, two produced anti-SARS-CoV-2 spike antibody titers to a seroprotective level, and also produced HI titers against A/H1N1 to a seroprotective level. Another 2 KTRs did not produce seroprotective anti-SARS-CoV-2 antibody titers, but produced seroprotective HI titers against A/H1N1. The remaining KTR produced a seroprotective anti-SARS-CoV-2 antibody titer, but did not produce a seroprotective HI titer against A/H1N1. The 2 KTRs who did not produce seroprotective anti-SARS-CoV-2 antibody titers following vaccination, later developed COVID-19, and this infection increased their titers over the seroprotective level. This study demonstrated that inter- and intra-individual differences in biological responses to vaccines should be considered in pediatric KTRs, in addition to immunosuppressant effects. Personalized regimens, such as augmented or booster doses of vaccines, could potentially improve the vaccination efficacy against SARS-CoV-2 and influenza.

Plasma exchange is an effective treatment for Kawasaki disease (KD), suggesting that plasma from patients with KD bears its causative agents. The aim of this study was to use mass spectrometry to identify candidate agents in patient sera. Serum samples were obtained from 17 KD patients. In six patients, samples were collected in each of three phases: the acute phase prior to acetylsalicylic acid (ASA) and intravenous immunoglobulin administration (Phase A1), the remission phase with ASA (Phase A2), and the remission phase without any medication (Phase A3). Sera from the remaining 11 patients were collected during Phases A1 and A2. The study also included two age- and gender-matched control groups, one with eight afebrile children and one with eight febrile children diagnosed with infectious disease. Patients in Phase A1 and febrile controls did not differ in body temperature, white blood cell counts, or C-reactive protein levels. Mass spectrometry analysis revealed that the intensity levels of m/z 9416, identified as apolipoprotein CIII (Apo CIII), were lower in Phase A1 samples compared with samples from patients in Phases A2 and A3, and from febrile controls (all comparisons, p < 0.01). Serum Apo CIII levels were also lower in Phase A1 samples compared with samples from Phase A2 patients and afebrile controls (both p < 0.01), but samples from patients in Phase A2 did not differ significantly from those of the afebrile controls (p = 0.55). This study demonstrated that serum Apo CIII level was decreased in the acute phase of KD.

RATIONALE: Vacuolated podocytes are the most common form of renal damage in Fabry disease, but other types of renal damage have been reported, such as membranous nephropathy (MN) or IgM nephropathy. Enzyme replacement therapy (ERT) is effective at preventing renal damage, but the nephropathies require appropriate treatment to prevent renal damage. PATIENT CONCERNS: A 22-year-old male with Fabry disease presented with proteinuria during ERT with agalsidase-β and carbamazepine. He had received the treatment for 10 years and maintained normal plasma globotryaosylceramide levels. DIAGNOSIS: Renal biopsy revealed MN without vacuolated podocytes. Immunofluorescent staining of the IgG subclass revealed granular patterns of IgG1, G2, G4, and C3 deposition in the glomerular basement membrane. INTERVENTIONS: The carbamazepine dose was reduced from 600 mg/day to 200 mg/day (serum concentration 10.0-11.0-4.0-5.0 μg/mL). OUTCOMES: After reducing the carbamazepine dose, proteinuria was negative, and the patient has had a normal urinalysis for 17 months. Plasma globotryaosylceramide levels have also remained normal. LESSONS: This report is a reminder of the co-existence of MN without vacuolated podocytes in Fabry disease during ERT with agalsidase-β and carbamazepine.Physicians should be aware of this form of renal damage in Fabry disease, even during treatment.

AIM: Glucocorticoids (GC) are essential medicines for idiopathic steroid-sensitive nephrotic syndrome (ISSNS) and IgA nephropathy (IgAN), with good clinical results. However, they cause bone fragility. The aim of this study was to elucidate GC effects on bone strength assessed as bone mineral density (BMD) and bone quality, using bone turnover markers (BTM), in children with ISSNS or IgAN. METHODS: Eleven children with ISSNS and 13 with IgAN were included. All the patients received GC treatment according to each protocol. The BMD and BTM-serum alkaline phosphatase (S-ALP), tartrate-resistant acid phosphatase 5b (S-TRACP-5b), and undercarboxylated osteocalcin (S-ucOC)-were measured from the initiation of steroid treatment (STx) to the end of STx in both groups. RESULTS: In ISSNS, S-ALP and S-ucOC levels were decreased significantly at 1 month. BMD and S-TRACP-5b levels showed no significant change through this observation period. In IgAN, BMD and S-ALP levels were decreased significantly at 1 and 3 months, respectively, and recovered to baseline at 10 months after the initiation of GC dosage reduction. S-TRACP-5b levels were decreased significantly at 3 months and remained lower than at baseline through the observation period. In both groups, S-ucOC levels did not directly reflect bone strength. CONCLUSION: This study clarified the following three points regarding GC effects on bone strength in children with ISSNS or IgAN: first, S-ALP is a more sensitive bone quality marker than S-TRACP-5b; second, BMD loss was observed only when both S-ALP and S-TRACP-5b levels decreased, and third, S-ucOC levels do not directly reflect bone strength.

In individuals treated with immunosuppressive therapies, the varicella-zoster virus (VZV) infection can become disseminated and lead to a life-threatening condition. There is currently no established treatment strategy for this life-threatening condition. Here, we describe a case where plasma exchange (PE) with a high dose of acyclovir (ACV) ameliorated the severe effects, including VZV-hemophagocytic lymphohistiocytosis (VZV-HLH) and disseminated intravascular coagulation (DIC), in a 9-year-old girl with steroid-dependent nephrotic syndrome. This 9-year-old girl experienced frequent relapse steroid-dependent nephrotic syndrome. She had been treated with steroids, tacrolimus, mizoribine, and rituximab. She had not previously received a varicella vaccine. She was admitted with only one vesicular rash. At admission, a serum test revealed 1.6 × 106 copies/mL of VZV DNA. The patient rapidly developed VZV-HLH and DIC. A combination of a high dose of ACV, immunoglobulin, and steroid pulse therapy could not improve these severe complications. Therefore, PE was applied. PE with a high dose of ACV successfully reduced serum VZV DNA from 7.5 × 106 to 2.8 × 104 copies/mL. This reduction in the VZV DNA copy number suggested that the combination of PE and a high dose of ACV was effective in treating a disseminated VZV infection. To the best of our knowledge, this is the first report showing that PE with a high dose of ACV ameliorated the severe complications of disseminated VZV by reducing the VZV DNA copy number.

BACKGROUND: We previously reported that the top-down approach (TDA) for infants with febrile urinary tract infections (fUTI) could prevent recurrent fUTI (r-fUTI) but produced a high number of false-positives on acute-phase 99m Tc dimercaptosuccinic acid (DMSA) renal scintigraphy. Therefore we compared the ultrasonography-oriented approach (USOA) with TDA from the viewpoint of prevention of r-fUTI. METHODS: The TDA was applied between July 2010 and February 2014 and the USOA was applied between March 2014 and April 2017 in infants with first fUTI. In the USOA group, voiding cystourethrography (VCUG) was performed in the case of abnormality on acute-phase renal bladder ultrasonography (RBUS) or on chronic- phase DMSA, which were performed in all cases. The frequency of r-fUTI was compared between the TDA group and USOA group retrospectively. RESULTS: Seventy-four infants (52 male) and 79 infants (60 male) received TDA or USOA, respectively. No significant differences were found between the TDA and USOA groups in male : female ratio, age in months at initial onset of fUTI, observation period, or number of cases of r-fUTI (TDA group, n = 4; USOA group, n = 5). Seventy-four DMSA scintigraphy and 25 VCUG were carried out in the USOA group, and 111 DMSA scintigraphy and 34 VCUG in the TDA group. CONCLUSIONS: Both USOA and TDA were valid for prevention of r-fUTI, but USOA was superior to TDA with regard to the reduced number of patients undergoing VCUG and DMSA.

BACKGROUND: C1q nephropathy (C1qN) was first described as glomerular disease characterized by predominant meangial C1q deposits in patients with proteinuria and no evidence of systemic lupus erythematosus. Several studies, however, revealed the clinical heterogeneity of C1qN, showing some cases with normal urinalysis. To confirm the existence of cases with predominant mesangial C1q deposits and negative or mild proteinuria and/or hematuria, we investigated renal graft biopsy specimens showing negative to mild proteinuria (less than or equal to 1+ by dip stick test) and/or hematuria. METHODS: Eligible participants were kidney transplant cases who corresponded to the criteria for C1qN and were followed more than 10 years. Their medical records were reviewed to determine the age at detection of predominant mesangial C1q deposits, gender, original renal disease and reason for renal graft biopsy, blood pressure, degree of proteinuria and hematuria, and serum creatinine levels. RESULTS: From 414 cases in adults and children, five pediatric patients (the male to female ratio, 1:1.5) were eligible. At the time when predominant mesangial C1q deposits were detected, 2 cases presented with mild proteinuria without hematuria, but the other 3 cases showed normal urinalysis. Light microscopy revealed minor glomerular abnormality in all the cases. Immunofluorescent study showed predominant mesangial C1q deposits with IgG, IgM and C3 in all cases. All selected specimens presented electron dense-depos in the mesangium. Ten years later from the detection, 2 cases continued to be normal urinalysis and 3 cases had mild proteinuria without hematuria. During this follow-up period, no cases presented with persistent proteinuria and/or hematuria greater than or equal to 2+ by dip stick test. And no cases developed systemic lupus erythematosus. Follow-up renal graft biopsies were performed once in 2 cases 8 years later from the detection. They showed minor glomerular abnormalities. C1q deposit disappeared in one case. In another case, immunofluorescent study was not examined. CONCLUSIONS: This long-term observational study on transplanted kidneys confirms the existence of cases with predominant but silent C1q deposits in the mesangium who have negative or mild proteinuria.

UNLABELLED: In Fabry disease, globotriaocylceramid (GL3) starts to accumulate in kidney cells in utero, and continues to accumulate throughout childhood and adulthood with progressive tissue damage, which may lead to renal failure. MATERIAL AND METHODS: Eight children with classical Fabry disease, median age 12 (range 4-16 years) had a renal biopsy performed before the initiation of enzyme replacement therapy (ERT). All patients were normalbuminuric and had normal GFR. Three patients were re-biopsied after three or five years. RESULTS: In all patients, significant GL3-accumulation was found in several types of kidney cells with high amounts of GL3 in the podocytes. Segmental podocyte foot process effacement was shown in all but two patients; no effacement was seen neither in the youngest male patient at 4 years of age nor in a male aged 12. A 12-year-old female patient had normal podocyte foot processes before the start of ERT, but de novo foot process flattening and unchanged high score of podocyte GL3 accumulation were seen in the re-biopsy after three years of ERT (agalsidase alpha 0.2 mg/kg/every other week). Two boys showed worsening of podocyte effacement in kidney biopsy after five years of agalsidase alpha 0.2 mg/kg/eow. CONCLUSIONS: Podocyte foot process effacement was found in the majority of eight young classical Fabry patients of both genders after the age of 11 years, without clinical signs of Fabry nephropathy. Kidney biopsies are essential in the early diagnosis of nephropathy and in the evaluation of the response to enzyme replacement therapy of early Fabry nephropathy.

Tubulointerstitial nephritis and uveitis (TINU) syndrome, which was first described in 1975, has been reported in more than 130 patients, mostly in adolescent or young women. Although data concerning the etiologic background of this inflammatory disease are limited, several humoral factors, including cytokines, have been reported in association with the disease. Here, we report a case of TINU in a 14-year-old girl, whose renal and ophthalmological improvement was associated with the decrease of serum levels of tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and interleukin-8 (IL-8). This suggests the presence of T-cell-mediated immunity in this unique syndrome.