[Collapsing focal segmental glomerulosclerosis induced by cytomegalovirus: A case report]

Virus-Associated Nephropathies: A Narrative Review

While most viral infections cause mild symptoms and a spontaneous favorable resolution, some can lead to severe or protracted manifestations, specifically in immunocompromised hosts. Kidney injuries related to viral infections may have multiple causes related to the infection severity, drug toxicity or direct or indirect viral-associated nephropathy. We review here the described virus-associated nephropathies in order to guide diagnosis strategies and treatments in cases of acute kidney injury (AKI) occurring concomitantly with a viral infection. The occurrence of virus-associated nephropathy depends on multiple factors: the local epidemiology of the virus, its ability to infect renal cells and the patient's underlying immune response, which varies with the state of immunosuppression. Clear comprehension of pathophysiological mechanisms associated with a summary of described direct and indirect injuries should help physicians to diagnose and treat viral associated nephropathies.

Monogenic focal segmental glomerulosclerosis: A conceptual framework for identification and management of a heterogeneous disease

Focal segmental glomerulosclerosis (FSGS) is not a disease, rather a pattern of histological injury occurring from a variety of causes. The exact pathogenesis has yet to be fully elucidated but is likely varied based on the type of injury and the primary target of that injury. However, the approach to treatment is often based on the degree of podocyte foot process effacement and clinical presentation without sufficient attention paid to etiology. In this regard, there are many monogenic causes of FSGS with variable presentation from nephrotic syndrome with histological features of primary podocytopathy to more modest degrees of proteinuria with limited evidence of podocyte foot process injury. It is likely that genetic causes are largely underdiagnosed, as the role and the timing of genetic testing in FSGS is not established and genetic counseling, testing options, and interpretation of genotype in the context of phenotype may be outside the scope of practice for both nephrologists and geneticists. Yet most clinicians believe that a genetic diagnosis can lead to targeted therapy, limit the use of high-dose corticosteroids as a therapeutic trial, and allow the prediction of the natural history and risk for recurrence in the transplanted kidney. In this manuscript, we emphasize that genetic FSGS is not monolithic in its presentation, opine on the importance of genetic testing and provide an algorithmic approach to deployment of genetic testing in a timely fashion when faced with a patient with FSGS.

Cytomegalovirus-Associated Nephrotic Syndrome in a Patient with Myasthenia Gravis Treated with Azathioprine: A Case Report

BACKGROUND Patients taking azathioprine (AZA) are very susceptible to development of cytomegalovirus (CMV) infection. The symptoms of CMV infection are varied. In some rare cases, CMV infection can even result in nephrotic syndrome. CASE REPORT Here, we present a rare case of nephrotic syndrome associated with CMV infection, induced by azathioprine intake. The patient, diagnosed with myasthenia gravis, was initially treated with azathioprine for 2 years. Then, the patient was admitted to the hospital due to nephrotic syndrome and acute kidney injury. Minimal change disease with acute tubular necrosis were diagnosed through biopsy. After an initial good response to hemodialysis and steroids, the patient developed severe pneumonia and oral ulcers. Further anti-CMV IHC staining of kidney tissues showed positive cells in tubules, indicating nephrotic syndrome secondary to CMV infection. CONCLUSIONS This case reminded us that CMV may be an under-recognized cause of nephrotic syndrome. Patients treated with azathioprine are very susceptible to developing CMV infection. During the diagnosis of nephrotic syndrome, we should always take CMV infection into consideration, especially in patients with on azathioprine.