Acute kidney injury and risk factors in pediatric patients undergoing hematopoietic stem cell transplantation.

BACKGROUND: Acute kidney injury (AKI) is a common complication of hematopoietic stem cell transplantation (HSCT) with increased mortality and morbidity. Understanding the risk factors for AKI is essential. This study aimed to identify AKI incidence, risk factors, and prognosis in pediatric patients post-HSCT. METHODS: We conducted a retrospective case-control study of 278 patients who were divided into two groups: those with AKI and those without AKI (non-AKI). The groups were compared based on the characteristics and clinical symptoms of patients, as well as post-HSCT complications and the use of nephrotoxic drugs. Logistic regression analysis was employed to identify the risk factors for AKI. RESULTS: A total of 16.9% of patients had AKI, with 8.5% requiring kidney replacement therapy. Older age (OR 1.129, 95% CI 1.061-1.200, p < 0.001), sinusoidal obstruction syndrome (OR 2.562, 95% CI 1.216-5.398, p = 0.011), hemorrhagic cystitis (OR 2.703, 95% CI 1.178-6.199, p = 0.016), and nephrotoxic drugs, including calcineurin inhibitors, amikacin, and vancomycin (OR 17.250, 95% CI 2.329-127.742, p < 0.001), were identified as significant independent risk factors for AKI following HSCT. Mortality rate and mortality due to AKI were higher in stage 3 patients than those in stage 1 and 2 AKI (p = 0.019, p = 0.007, respectively). Chronic kidney disease developed in 1 patient (0.4%), who was in stage 1 AKI (2.1%). CONCLUSIONS: AKI poses a serious threat to children post-HSCT, leading to alarming rates of mortality and morbidity. To enhance outcomes and mitigate these risks, it is vital to identify AKI risk factors, adopt early preventive strategies, and closely monitor this patient group.

A rare cause of nephrotic syndrome-sphingosine-1-phosphate lyase (SGPL1) deficiency: 6 cases and a review of the literature.

BACKGROUND: Recently, recessive mutations in SGPL1 (sphingosine-1-phosphate lyase), which encodes the final enzyme of sphingolipid metabolism, have been reported to cause steroid-resistant nephrotic syndrome, adrenal insufficiency, and many other organ/system involvements. We aimed to determine the clinical and genetic characteristics, and outcomes in patients with SGPL1 mutations. METHODS: The study included 6 patients with bi-allelic SGPL1 mutation. Clinical, genetic, and laboratory characteristics, and outcomes of the patients were evaluated retrospectively. We also reviewed previously reported patients with SGPL1 mutations and compared them to the presented patients. RESULTS: The median age at kidney presentation was 5 months. Four patients (67%) were diagnosed before age 1 year. Kidney biopsy showed focal segmental glomerulosclerosis in 2 patients and diffuse mesangial sclerosis in one patient. Steroids were given to 3 patients, but they did not respond. All 6 patients progressed to chronic kidney disease; 5 required kidney replacement therapy (KRT) at a median age of 6 months. Deceased kidney transplantation was performed in one patient. All 6 patients had adrenal insufficiency, of which 5 were diagnosed at age < 6 months. Three patients had hypothyroidism, 2 had ichthyosis, 4 had immunodeficiency, 5 had neurological findings, and 2 had genitourinary system anomalies. Four patients died at a median age of 30.5 months. Two patients are being followed up with KRT. One patient had a novel mutation. CONCLUSIONS: Patients with SGPL1 mutations have a poor prognosis, and many types of extrarenal organ/system involvement beyond adrenal insufficiency can be seen. Genetic diagnosis of such patients is important for treatment, genetic counseling, and screening for comorbid conditions. A higher resolution version of the Graphical abstract is available as Supplementary information.

Evaluation of Hypersensitivity Reactions in Pediatric Patients Using Biological Drugs.

INTRODUCTION: Biological drugs are currently used for the treatment of chronic inflammatory, autoimmune, and neoplastic diseases. With their expanding indication spectrum and increasing use, hypersensitivity reactions to these drugs are also becoming more frequent. The present study aimed to report the incidence and the features of such reactions in pediatric patients using biologicals for the treatment of various diseases. METHODS: The medical records of pediatric patients treated with biological agents between October 1, 2011 and August 31, 2019 were reviewed and adverse reactions were evaluated retrospectively. RESULTS: During the study period, 211 patients (116 boys, 55%) used 21 different biological drugs for the treatment of various diseases. Their median age at the time of the first treatment was 139.9 (IQR: 92.2-187.8) months. Hematologic-oncologic diseases were the most common indication for biological therapy (97/211; 46.0%), followed by rheumatologic diseases (82/211; 38.9%). Of the 211 patients, 14 (6.64%) experienced reactions to biological drugs. The most common culprit agent was rituximab (57.1%). Most of the patients (85.7%) had a history of reactions either during the infusion or within 1 h after taking the drug. Five patients underwent desensitization to the culprit drug, while 7 other patients continued treatment with a reduced dose/infusion rate or premedication. Also 1 patient continued to take the drug without any additional treatment. CONCLUSION: It was reported that 6.64% of the patients who received biologic drug therapy for various reasons in our hospital had hypersensitivity. The most common culprit agent was rituximab, and most of the reactions were immediate reactions.

Algorithm for the diagnosis and management of the multisystem inflammatory syndrome in children associated with COVID-19.

OBJECTIVE: Although the initial reports of COVID-19 cases in children described that children were largely protected from severe manifestations, clusters of paediatric cases of severe systemic hyperinflammation and shock related to severe acute respiratory syndrome coronavirus 2 infection began to be reported in the latter half of April 2020. A novel syndrome called "multisystem inflammatory syndrome in children" (MIS-C) shares common clinical features with other well-defined syndromes, including Kawasaki disease, toxic shock syndrome and secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome. Our objective was to develop a protocol for the evaluation, treatment and follow-up of patients with MIS-C. METHODS: The protocol was developed by a multidisciplinary team. We convened a multidisciplinary working group with representation from the departments of paediatric critical care, cardiology, rheumatology, surgery, gastroenterology, haematology, immunology, infectious disease and neurology. Our protocol and recommendations were based on the literature and our experiences with multisystem inflammatory syndrome in children. After an agreement was reached and the protocol was implemented, revisions were made on the basis of expert feedback. CONCLUSION: Children may experience acute cardiac decompensation or other organ system failure due to this severe inflammatory condition. Therefore, patients with severe symptoms of MIS-C should be managed in a paediatric intensive care setting, as rapid clinical deterioration may occur. Therapeutic approaches for MIS-C should be tailored depending on the patients' phenotypes. Plasmapheresis may be useful as a standard treatment to control hypercytokinemia in cases of MIS-C with severe symptoms. Long-term follow-up of patients with cardiac involvement is required to identify any sequelae of MIS-C.

IgG4-related disease and ANCA positive vasculitis in childhood: a case-based review.

Autoimmune pancreatitis (AIP) type 1 is an IgG4-related disease (IgG4-RD), characterized by inflammatory pseudotumors and histologically by dense lymphoplasmacytic infiltrates rich in IgG4 positive plasma cells, storiform fibrosis, and obliterative phlebitis. Although quite rare, IgG4-RD was found to be associated with medium or small vessel vasculitides. A new overlap syndrome between IgG4-RD and ANCA-associated vasculitis (AAV) has recently been described in the adult population. Here we present a 16-year-old adolescent girl admitted with abdominal pain, episcleritis, palpable purpura, salivary gland enlargement, and bloody diarrhea. Laboratory investigations revealed findings of glomerulonephritis. Abdominal imaging surprisingly revealed a focal mass in the pancreatic tail, while the c-ANCA level was found to be quite high as well as serum IgG4 level. Biopsy of the pancreatic mass showed lymphoplasmacytic IgG4 positive cells infiltrating the pancreas with storiform fibrosis compatible with IgG4-related AIP. The renal biopsy that was done simultaneously showed necrotizing granulomatous vasculitis indicating AAV. Renal biopsy showed IgG4 positive plasma cells very rarely by immunohistochemical examination, which does not indicate any significance for IgG4-RD. Our diagnosis was IgG4-related AIP and AAV overlap syndrome, which has not been reported in the pediatric populations yet. IgG4-RD should be investigated in patients with ANCA-associated vasculitis who shows atypical organ involvement. We searched the Pubmed/Medline and Google Scholar databases to identify clinical findings, treatment, and outcome of the patients with IgG4-related AIP and AAV.

Hypokalemia and hearing loss in a 3-year-old boy: Questions.

Bartter syndrome with sensorineural deafness (Bartter syndrome type 4) is an autosomal recessive disorder characterized with polyhydramniosis, premature birth, massive polyuria, renal salt-wasting, hypokalemic metabolic alkalosis, normotensive hyperreninemic hyperaldosteronism, and hearing loss. Homozygous mutations in BSND, CLCNKA, and CLCNKB mutations cause the disorder. Here we report a 3-year-old boy who had not been evaluated and investigated before cochlear implantation. Hypokalemia was detected during the routine laboratory workup before surgery. Further analyses revealed metabolic alkalosis with high renin and aldosterone levels. Hypokalemia improved with oral potassium chloride supplementation. Genetic tests revealed a homozygous c.139G>A (pG47R) mutation in BSND gene, and both parents were heterozygous for the same mutation. We want to emphasize the importance of evaluating hearing loss in children, since some of the genetic syndromes may cause life threatening abnormalities.

C3 glomerulopathy in NLRP12-related autoinflammatory disorder: case-based review.

Autoinflammatory diseases (AIDs) are a recently described group of conditions caused by mutations in multiple genes that code for proteins of the innate immune system. Cryopyrin-associated periodic syndromes (CAPS) are autoinflammatory diseases comprising three clinically overlapping disorders: familial cold urticarial syndrome (FCAS), Muckle-Wells syndrome (MWS), and neonatal-onset multisystem inflammatory disease (NOMID). CAPS have been associated with gain-of-function variations in NLRP3 (NOD-like receptor family, pyrin containing domain-3). However, a new class of autoinflammatory disease resembling FCAS or MWS has been described in patients with NLRP12 mutations. Here, we report a 6-year-old boy diagnosed with AID who developed an unexpected C3 glomerulopathy during attacks and carried a novel variation in NLRP12. Following treatment with IL (interleukin) 1 targeting agents, all symptoms and inflammation resolved. This is the first case in the literature affected by both autoinflammatory disease and C3 glomerulopathy.

Micronuclei and other nuclear anomalies in buccal epithelial cells of children with chronic kidney disease.

The objective of this study was to reveal the likely genomic instability in children with chronic kidney disease (CKD) using micronucleus (MN) assay on buccal epithelial cells (BEC). We investigated the frequencies of micronuclei and other nuclear anomalies, such as nuclear buds, binucleated cells, condensed chromatin, and karyorrhectic and pyknotic cells in BEC. Children with CKD were grouped as follows: children in the pre-dialysis (PreD) stage (N=17), children on regular haemodialysis (HD) (N=14), and children who have undergone transplantation (Tx) (N=17). As a control group, twenty age- and gender-matched healthy children were selected. The MN frequency in BEC of all groups of children with CKD was significantly elevated (5- to 7-fold) as compared to the control group (p<0.001). In contrast, the frequencies of nuclear buds were not significantly higher in the study groups compared to the control group. The frequencies of binucleated cells and condensed chromatin cells were significantly higher in all subgroups of children with CKD relative to the control group (p<0.001). Our results show that the BEC of pediatric PreD, HD, and Tx patients with CKD display increased cytogenetic, cytokinetic, and cytotoxic effects. They also point to the sensitivity and usefulness of the BEC MN assay in the assessment of genetic susceptibility of patients with CKD.

Antibody-mediated rejection and treatment in pediatric patients: one center's experience.

OBJECTIVES: Antibody-mediated rejection is a rare complication that often results in the loss of the kidney graft. Treatment options include plasmapheresis, intravenous immunoglobulin, and use of rituximab. MATERIALS AND METHODS: We retrospectively evaluated the data files from 86 pediatric renal transplant patients over the last 5 years. A biopsy was taken for each rejection episode. RESULTS: Seven patients (7.7%) developed antibody-mediated rejection. All patients with antibody-mediated rejection had histologic evidence of severe acute humoral rejection and extensive C4d staining in peritubular capillaries. Staining was diffuse (involving > 50% of peritubular capillaries) for 4 biopsies, and it was focal (involving < 50% of peritubular capillaries) for 3 biopsies. Twelve biopsies demonstrated at least 1 histologic feature associated with acute humoral rejection. Donor-specific antibodies were evaluated in recipients. The mean peak panel reactive antibody class 1 was 7.16% (range, 0%-86%). The mean time between rejection episodes and the transplant was 16.9 ± 13.5 months. All patients were treated with high-dose intravenous methylprednisolone and intravenous immunoglobulin. Three patients recovered renal function rapidly after this treatment. Donor-specific antibodies were negative in these patients. Five sessions of plasmapheresis were used simultaneously in these 4 patients. In 3 resistant patients, rituximab was prescribed after plasmapheresis and intravenous immunoglobulin. The presence of donor-specific antibodies was demonstrated in 4 patients. Two patients were refractory to antibody-mediated rejection treatment and lost their transplants. One patient had interstitial fibrosis and tubular atrophy during the 16th month after her antibody-mediated rejection. Graft survival in patients with antibody-mediated rejection at the end of 1 year was 71.4%. CONCLUSIONS: Early diagnosis and treatment with plasmapheresis, intravenous immunoglobulin, and rituximab may resolve antibody-mediated rejection. Although effective therapy is available for acute antibody-mediated rejection, the allograft remains at risk for chronic antibody-mediated rejection and shortened survival.

Basal damage and oxidative DNA damage in children with chronic kidney disease measured by use of the comet assay.

One consequence of chronic kidney disease (CKD) is an elevated risk for cancer. There is sufficient evidence to conclude that there is an increased incidence of at least some cancers in kidney-dialysis patients. Cancer risk after kidney transplantation has mainly been attributed to immunosuppressive therapy. There are no data evaluating DNA damage in children with CKD, in dialysis patients, or following kidney transplantation. In this study, the comet assay and the enzyme-modified comet assay - with the use of endonuclease III (Endo III) and formamidopyrimidine glycosylase (FPG) enzymes - were conducted to investigate the basal damage and the oxidative DNA damage as a result of treatment in peripheral blood lymphocytes of children. Children at various stages of treatment for kidney disease, including pre-dialysis patients (PreD) (n=17), regular hemodialysis patients (HD) (n=15), and those that received kidney transplants (Tx) (n=17), comprised the study group. They were compared with age- and gender-matched healthy children (n=20) as a control group. Our results show that the %DNA intensity, a measure of basal damage, was significantly increased in children with CKD (mean ± SD) (5.22 ± 1.57) and also in each of the PreD, HD, and Tx groups [(4.92 ± 1.23), (4.91 ± 1.35), and (5.79 ± 1.94), respectively, vs the healthy children (2.74 ± 2.91) (p<0.001). Significant increases in oxidative DNA damage were only found in the FPG-sensitive sites for the PreD and Tx groups, compared with control and HD groups (p<0.05), suggesting that basal DNA damage was more evident for the PreD, HD, and Tx groups. The findings of the present study indicate a critical need for further research on genomic damage with different endpoints and also for preventive measures and improvements in treatment of pediatric patients, in order to improve their life expectancy.

Micronucleus frequencies in peripheral blood lymphocytes of children with chronic kidney disease.

One of the crucial adverse effects of chronic kidney disease (CKD) and its treatment is an elevated cancer risk. There are no data on cytogenetic effects in children with CKD or children undergoing dialysis or those who have received a transplant. In this study, cytogenetic effects in children with CKD in pre-dialysis (PreD) stage, on regular haemodialysis (HD) and transplanted (Tx) compared with a control group of healthy children has been investigated using the cytokinesis-blocked micronucleus (CBMN) assay and fluorescence in situ hybridisation (FISH) combined with CBMN (CBMN-FISH) in peripheral blood lymphocytes. The results revealed a significant increase (P < 0.001) in micronucleus (MN) frequencies [mean ± SD (n)] in the PreD, HD and Tx groups versus the control group [CBMN assay; 9.19 ± 2.61 (16), 9.07 ± 4.86 (15), 6.12 ± 5.33 (17) versus 1.60 ± 0.99 (20), respectively]. Moreover, centromere negative micronucleus (C- MN) and centromere positive micronucleus (C+ MN) frequencies were significantly higher in each subgroup children (PreD, HD and Tx) than in the control group (P < 0.01) although children in Tx group had lower C- MN frequencies than PreD and lower C+ MN frequencies than PreD and HD groups (P < 0.05). Additionally, MN frequencies in mononuclear cells, nucleoplasmic bridges and nuclear buds in binucleated cells were increased in children with CKD (P < 0.001, P < 0.001, P > 0.05, respectively). The nuclear division index significantly decreased in Tx group relative to the control, PreD and HD groups (P < 0.001). Associations between cytogenetic parameters and creatinine or blood urea nitrogen were found (P < 0.05). To provide longer and better life expectancy of children with CKD and treatment modes, further research is needed to better understand and avoid these effects.

Parvovirus B19-induced multisystemic vasculitis and acute endocapillary proliferative glomerulonephritis in a child.

A 10-year-old girl was admitted with fever, cough, maculopapular rash, hemoptysis, dark-colored urine, edema, multiple lymphadenopathies, and hepatosplenomegaly. She developed acute glomerulonephritis during the course of these complex clinical features. Laboratory data showed hematuria, proteinuria, and hypocomplementemia. Serological tests showed positive human parvovirus B19 (HPVB19)-specific immunoglobin M (IgM) and HPVB19 DNA was detected in the patient's serum using polymerase chain reaction (PCR). Renal biopsy revealed acute endocapillary proliferative glomerulonephritis (AEPGN) with coarse granular C3 depositions in a "starry sky pattern," which is more peculiar to poststreptococcal glomerulonephritis. Electron microscopy showed subendothelial and small hump-shaped subepithelial electron-dense deposits in glomerular capillary walls. There was no evidence of either any mycobacterial, staphylococcal, or streptococcal infection, and the diagnosis of Goodpasture syndrome and connective tissue disorders was excluded during clinical and laboratory investigations. A diagnosis of HPVB19-induced pleuropneumonitis and glomerulonephritis was made. Through a literature search there was no documented pediatric case of AEPGN induced by HPVB19, and this case represents, to our knowledge, the first time that a direct relationship between parvovirus infection and AEPGN has been demonstrated in a child.

Rituximab for post-transplant recurrences of FSGS.

A 14-yr-old boy whose primary kidney disease was FSGS developed severe recurrence of proteinuria immediately after a second living-related kidney transplant. Despite pre- and post-operative PP and immunosuppressive treatment consisting of steroids, CycA, daclizumab, and MMF, daily protein excretion and serum creatinine increased. We therefore administered rituximab on the fourth day of transplantation. He received four weekly doses of rituximab (375 mg/m(2)/dose), which resulted in a rapid clearing of circulating CD19-positive B cells, and remission of proteinuria was achieved six wk after the first rituximab treatment. Graft function was excellent six months after transplantation with proteinuria of 8 mg/m(2)/h. We conclude that rituximab may be an effective treatment for post-transplant recurrence of FSGS.

Renal Fanconi syndrome and myopathy after liver transplantation: drug-related mitochondrial cytopathy?

Advances in the field of transplantation provide a better quality of life and allow more favorable conditions for growth and development in children. However, combinations of different therapeutic regimens require consideration of potential adverse reactions. We describe a 15-yr-old girl who had orthotopic liver transplantation because of Wilson's disease. Tacrolimus, MMF, and steroids were given as immunosuppressant. Lamivudine was added because of de nova hepatitis B infection during her follow-up. Three yr after transplantation she developed renal Fanconi syndrome with severe metabolic acidosis, hypophosphatemia, glycosuria, and aminoaciduria. Although tacrolimus was suspected to be the cause of late post-transplant renal acidosis and was replaced by sirolimus, acidosis, and electrolyte imbalance got worse. Proximal muscle weakness has developed during her follow-up. Fanconi syndrome, as well as myopathy, is well recognized in patients with mitochondrial disorders and caused by depletion of mtDNA. We suggest that our patient's tubular dysfunction and myopathy may have resulted from mitochondrial dysfunction which is triggered by tacrolimus and augmented by lamivudine.

Cytomegalovirus-related congenital nephrotic syndrome with diffuse mesangial sclerosis.

This case report describes congenital nephrotic syndrome in a 2-month-old girl associated with cytomegalovirus infection. Histological examination on renal biopsy showed diffuse mesangial sclerosis and cytomegalic inclusion bodies in the tubular cells and in some glomeruli. Cytomegalovirus (CMV) polymerase chain reaction (PCR) titer in serum was high. Remission of pulmonary and renal symptoms was achieved with ganciclovir in 3 weeks. No recurrence of proteinuria was observed during the follow-up period of 14 months. These finding suggested a causal relationship between congenital nephrotic syndrome and cytomegalovirus infection.

Direct adsorption of lipoproteins from whole blood by direct adsorption of lipoprotein apheresis: first experience in two hypercholesterolemic children.

Low density lipoprotein (LDL) cholesterol apheresis, combined with lipid lowering drugs, provides a safe and effective means of improving the prognosis of patients with homozygote familial hypercholesterolemia, especially if started before the age of seven. The direct adsorption of lipoprotein (DALI) is the first extracorporeal low density lipoprotein removing system compatible with whole blood. The purpose of the present study was to clarify the efficacy and safety of DALI in children with homozygous familial hypercholesterolemia. Two boys, aged 9 and 15 years, with familial hypercholesterolemia, who were highly resistant to dietary regimes and to drug therapy, were treated with the low density lipoprotein adsorber DALI apheresis once every 2 weeks for 24 weeks. The treated blood volumes for each procedure were 2911 mL (493 +/- SD) and 5982 mL (1129 +/- SD), respectively. In our patients, the acute mean LDL cholesterol reductions were 44.7 +/- 8.9% and 58.8 +/- 4.5%. The corresponding reductions were 42.5 +/- 7.2% and 56 +/- 4.3% for total cholesterol, and 46.5 +/- 17.1% and 55 +/- 7.5% for very low density lipoprotein cholesterol (VLDL-C). There were insignificant losses of high density lipoprotein (12.2 +/- 5.7%, 8.3 +/- 5.5%). Treatment was well tolerated in general, and neither patient suffered from irreversible or long-lasting adverse effects. Our experience with DALI apheresis is encouraging. The present report is the first on the use of DALI in children. Based on this short-term evaluation we think that DALI might be safe and effective in children with homozygote familial hypercholesterolemia, however further evaluation of long-term effects is needed.