AKI and Collapsing Glomerulopathy Associated with COVID-19 and APOL 1 High-Risk Genotype.

BACKGROUND: Kidney involvement is a feature of COVID-19 and it can be severe in Black patients. Previous research linked increased susceptibility to collapsing glomerulopathy, including in patients with HIV-associated nephropathy, to apo L1 (APOL1) variants that are more common in those of African descent. METHODS: To investigate genetic, histopathologic, and molecular features in six Black patients with COVID-19 presenting with AKI and de novo nephrotic-range proteinuria, we obtained biopsied kidney tissue, which was examined by in situ hybridization for viral detection and by NanoString for COVID-19 and acute tubular injury-associated genes. We also collected peripheral blood for APOL1 genotyping. RESULTS: This case series included six Black patients with COVID-19 (four men, two women), mean age 55 years. At biopsy day, mean serum creatinine was 6.5 mg/dl and mean urine protein-creatinine ratio was 11.5 g. Kidney biopsy specimens showed collapsing glomerulopathy, extensive foot process effacement, and focal/diffuse acute tubular injury. Three patients had endothelial reticular aggregates. We found no evidence of viral particles or SARS-CoV-2 RNA. NanoString showed elevated chemokine gene expression and changes in expression of genes associated with acute tubular injury compared with controls. All six patients had an APOL1 high-risk genotype. Five patients needed dialysis (two of whom died); one partially recovered without dialysis. CONCLUSIONS: Collapsing glomerulopathy in Black patients with COVID-19 was associated with high-risk APOL1 variants. We found no direct viral infection in the kidneys, suggesting a possible alternative mechanism: a "two-hit" combination of genetic predisposition and cytokine-mediated host response to SARS-CoV-2 infection. Given this entity's resemblance with HIV-associated nephropathy, we propose the term COVID-19-associated nephropathy to describe it.

Arterial vascular access complication in osteogenesis imperfecta.

We present a case of the catastrophic bleeding from the femoral access site after an uncomplicated puncture in a patient with Type 1 osteogenesis imperfecta (OI) undergoing coronary angiogram via the femoral route. This had to be treated with a covered stent at the puncture site. This is an extremely rare complication in OI. The potential pathological mechanisms of this complication are discussed. An interventionist will rarely encounter such a patient in the catheterisation laboratory but would do well to be aware of this potential complication.

Posttransplant lymphoproliferative disorders.

Posttransplant lymphoproliferative disorder is a heterogeneous group of clonal hyperplasia/neoplasms that can range from benign to highly malignant lesions. Mortality rates can approach 60%. This entity has been on the rise for the last 2 decades with the advent of highly potent immunosuppressive agents. Epstein-Barr virus has shown to play a primary role in more than 90% of the cases. Although standard protocols do not exist for primary prevention and treatment, new agents are emerging that may play a role in treatment and prevention of this debilitating, and at times, fatal disease.