Meningococcemia in a vaccinated child receiving eculizumab and review of the literature.

BACKGROUND: Atypical hemolytic uremic syndrome (aHUS) is a rare and severe disease characterized by uncontrolled activation and dysregulation of the alternative complement pathway and development of thrombotic microangiopathy. Eculizumab, which is used as a first-line therapy in aHUS, blocks the formation of C5 convertase and inhibits the formation of the terminal membrane attack complex. It is known that treatment with eculizumab increases the risk of meningococcal disease by 1000-2000-fold. Meningococcal vaccines should be administered to all eculizumab recipients. CASE: We describe a girl with aHUS who was receiving eculizumab treatment and experienced meningococcemia with non-groupable meningococcal strains which rarely cause disease in healthy people. She recovered with antibiotic treatment and we discontinued eculizumab. CONCLUSIONS: In this case report and review, we discussed similar pediatric case reports in terms of meningococcal serotypes, vaccination history, antibiotic prophylaxis and prognosis of patients who experienced meningococcemia under eculizumab treatment. This case report highlights the importance of a high index of suspicion for invasive meningococcal disease.

Humoral and cellular immune response to SARS-CoV-2 mRNA BNT162b2 vaccine in pediatric kidney transplant recipients compared with dialysis patients and healthy children.

BACKGROUND: Compared with the general population, the immune response to COVID-19 mRNA vaccines is lower in adult kidney transplant recipients (KTRs). However, data is limited for pediatric KTRs. In this study, we aimed to assess humoral and cellular immune responses to the COVID-19 mRNA vaccine in pediatric KTRs. METHODS: This multicenter, prospective, case-control study included 63 KTRs (37 male, aged 12-21 years), 19 dialysis patients, and 19 controls. Humoral (anti-SARS-CoV2 IgG, neutralizing Ab (nAb)) and cellular (interferon-gamma release assay (IGRA)) immune responses were assessed at least one month after two doses of BNT162b2 mRNA vaccine. RESULTS: Among COVID-19 naïve KTRs (n = 46), 76.1% tested positive for anti-SARS-CoV-2 IgG, 54.3% for nAb, and 63% for IGRA. Serum levels of anti-SARS-CoV-2 IgG and nAb activity were significantly lower in KTRs compared to dialysis and control groups (p < 0.05 for all). Seropositivity in KTRs was independently associated with shorter transplant duration (p = 0.005), and higher eGFR (p = 0.007). IGRA titer was significantly lower than dialysis patients (p = 0.009). Twenty (43.4%) KTRs were positive for all immune parameters. Only four of 11 seronegative KTRs were IGRA-positive. COVID-19 recovered KTRs had significantly higher anti-SARS-CoV-2 IgG and nAb activity levels than COVID-19 naïve KTRs (p = 0.018 and p = 0.007, respectively). CONCLUSIONS: The humoral and cellular immune responses to SARS-CoV-2 mRNA BNT162b2 vaccine are lower in pediatric KTRs compared to dialysis patients. Further prospective studies are required to demonstrate the clinical efficacy of the mRNA vaccine in KTRs. This prospective study was registered in ClinicalTrials.gov (NCT05465863, registered retrospectively at 20.07.2022). A higher resolution version of the Graphical abstract is available as Supplementary information.

Long-term Results in Children with Henoch-Schönlein Nephritis.

Objective: Henoch-Schönlein purpura (HSP) is a small vessel vasculitis and palpable purpura, with arthritis, gastrointestinal as abdominal pain, and renal involvement as typical clinical findings. The most important prognostic factor for HSP vasculitis is renal involvement. This study aimed to investigate the relationship between clinical, laboratory, and histopathologic findings of children with HSP nephritis with long-term renal prognosis. Methods: This retrospective study included children with HSP nephritis between January 2010 and December 2019. Initial clinical presentation, laboratory findings, and kidney biopsy results were obtained, and treatment modalities were recorded and classified using the Meadow classification and grouped into mild and severe cases. Additionally, data at the last follow-up were analyzed and classified. Results: A total of 90 children (59 male) with a mean age of 8.8±3.2 years were included. According to initial clinical findings, 18 children were in the Meadow's severe group. Fifteen (15/72) children in the mild group and all children in the severe group had undergone kidney biopsy. The severe group had higher histopathologic stages compared to the mild group (p=0.022). Immunosuppressive treatments were used in 44.4% of mild cases and 100% of severe cases (p<0.01). On follow-up, only four children (two in the mild group) had persistent proteinuria. Conclusions: Severe clinical findings in the initial presentation were related to more intensive immunosuppressive treatment. Additionally, renal histopathological stages were higher in the severe group. Long-term follow-up for proteinuria is mandatory for all children with HSP nephritis, even with mild initial clinical findings.

Hepatocyte Nuclear Factor 1 Beta Mutation-associated Newborn Onset of Glomerulocystic Kidney Disease: A Case Presentation.

Mutations in hepatocyte nuclear factor-1 beta (HNF1B) are the most commonly identified genetic cause of renal malformations. Heterozygous mutations are associated with renal cysts and diabetes syndrome. Various renal developmental abnormalities and maturity-onset diabetes of the young could be the presenting factors of these mutations. A 10-year-old boy who was evaluated for bilateral cystic kidneys and chronic kidney disease from the newborn period was diagnosed with HNF1B-related glomerulocystic disease by DNA sequencing. The differential diagnosis of autosomal dominant polycystic kidney disease was a diagnostic pitfall. The genetic screening of the family revealed his mother, sister, and brother to have the same mutation. Therefore, genetic diagnosis and counseling are important for cystic kidney diseases not only for formulating the diagnosis and early management plan but also for the diagnosis of potential asymptomatic cases in the family.