Arterial abnormalities identified in kidneys transplanted into children during the COVID-19 pandemic

COVID-19 associated pediatric vasculitis: A systematic review and detailed analysis of the pathogenesis

Objectives

Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2, has opened a new era in the practice of pediatric rheumatology since it has been associated with inflammatory complications such as vasculitis and arthritis. In this review, we aimed to present a detailed analysis of COVID-19 associated pediatric vasculitis.

Methods

A systematic review of the English literature was performed through Pubmed/MEDLINE and Scopus up to January 1st, 2022. Articles including data about the patients with 1) onset of vasculitis <18 years of age, 2) evidence of SARS-CoV-2 exposure, 3) evidence of vasculitis diagnosis (imaging, histopathologic evidences or fulfilling the specific diagnostic/classification criteria) were included in the final analysis. Patients with Kawasaki disease-like vasculitis associated with multisystem inflammatory syndrome in children (MIS-C) were excluded.

Results

A total of 25 articles describing 36 patients with COVID-19 associated pediatric vasculitis (median age 13 years; M/F: 2.3) were included. The most frequent phenotype was IgA vasculitis (n=9) followed by chilblains (n=7) and ANCA associated vasculitis (AAV) (n=5). Skin (58.3%) and renal (30.5%) involvements were the most common manifestations of vasculitis. The majority of patients received corticosteroids (40%), while rituximab (14.2%) and cyclophosphamide (11.4%) were the most frequently used immunosuppressive drugs. Remission was achieved in 23 of 28 patients. Five patients (4 with central nervous system vasculitis; 1 with AAV) died.

Conclusion

Although COVID-19 associated pediatric vasculitis is very rare, awareness of this rare entity is important to secure earlier diagnosis and treatment. The clinical features of COVID-19 associated pediatric vasculitis subtypes look similar to those in pediatric vasculitis not associated with COVID-19. Whether COVID-19 is the reason of the vasculitis or only the trigger remains unknown.

Pediatric transplantation during the COVID-19 pandemic

Children infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seem to have a better prognosis than adults. Nevertheless, pediatric solid organ transplantation (SOT) has been significantly affected by the unprecedented coronavirus disease 2019 (COVID-19) pandemic during the pre-, peri-, and post-transplant period. Undoubtedly, immunosuppression constitutes a real challenge for transplant clinicians as increased immunosuppression may prolong disease recovery, while its decrease can contribute to more severe symptoms. To date, most pediatric SOT recipients infected by SARS-CoV-2 experience mild disease with only scarce reports of life-threatening complications. As a consequence, after an initial drop during the early phase of the pandemic, pediatric SOTs are now performed with the same frequency as during the pre-pandemic period. This review summarizes the currently available evidence regarding pediatric SOT during the COVID-19 pandemic.

Intrinsic Kidney Pathology Following COVID-19 Infection in Children and Adolescents: A Systematic Review

Introduction: COVID-19 infections resulting in pathological kidney manifestations have frequently been reported in adults since the onset of the global COVID-19 pandemic in December 2019. Gradually, there have been an increased number of COVID-19-associated intrinsic kidney pathologies in children and adolescents reported as well. The pathophysiological mechanisms between COVID-19 and the onset of kidney pathology are not fully known in children; it remains a challenge to distinguish between intrinsic kidney pathologies that were caused directly by COVID-19 viral invasion, and cases which occurred as a result of multisystem inflammatory syndrome due to the infection. This challenge is made more difficult in children, due to the ethical limitations of performing kidney biopsies to reach a biopsy-proven diagnosis. Although previous systematic reviews have summarized the various pathological kidney manifestations that have occurred in adults following acute COVID-19 infection, such reviews have not yet been published for children and adolescents. We describe the results of a systematic review for intrinsic kidney pathology following COVID-19 infection in children and adolescents. Methods: A systematic literature search of published data up until 31 October was completed through the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) guidelines. Research articles reporting new-onset or relapsed intrinsic kidney pathology in children or adolescents (≤18 years) following acute COVID-19 infection were included for qualitative review. COVID-19 infection status was defined by a positive result from a RT-PCR, or nuclear antibody testing. Only full-text articles published in the English language were selected for review. Results: Twenty-nine cases from fifteen articles were included in the qualitative synthesis of this systematic review. Nephrotic syndrome, as an umbrella condition, appeared as the most frequently observed presentation (20 cases) with disease remission noted in all cases with steroid treatment. Other cases included numerous glomerulonephritides, such as acute necrotizing glomerulonephritis, MPO vasculitis and collapsing glomerulopathy, and thrombotic microangiopathies, such as aHUS. For patients with transplanted kidneys, T-cell-mediated rejection and mild tubular interstitial infiltration were noted following testing positive for COVID-19. There were no mortalities reported in any of the included cases, although two patients remained dialysis dependent at hospital discharge. Conclusion: This systematic review highlights the various intrinsic pathological kidney manifestations in children and adolescents as a result of acute COVID-19 infection. The clinical timeline and presentation of these cases support the mechanistic hypothesis between COVID-19 infection and the onset of intrinsic kidney pathologies within this context. The progressive introduction of vaccination programs for children and adolescents may hopefully reduce the severity of COVID-19-associated illnesses, and pathological kidney manifestations in this population.

COVID-19 and research in pediatric urology

COVID-19 began in December 2019 then spread worldwide. Providers, including pediatric urologists, had to adapt their clinical processes, and many non-covid research activities were suspended. COVID-19 impacts how research is financed, performed, and published, and is itself the subject of intense research. We present current research and publications specifically related to the urinary tract and the pediatric population.