An unusual form of kidney injury without glomerulonephritis in microscopic polyangiitis: a case report.

BACKGROUND: Microscopic polyangiitis (MPA), a kind of antineutrophil cytoplasmic autoantibody associated vasculitis (AAV), predominantly affects small-sized vessels. MPA is a significant cause of the pulmonary-renal syndrome. Pauci-immune necrotizing and crescentic glomerulonephritis is the typical renal histological feature of AAV. Tubulointerstitial lesions may occur and mostly form with inflammatory cell infiltration in the interstitium. However, a few cases reported only tubulointerstitial involvement without glomerular lesions in patients with MPA. CASE PRESENTATION: We present an MPA case, a 70-year-old male patient diagnosed with acute kidney injury accompanying the dialysis requirement. Only acute tubulointerstitial nephritis was revealed in kidney biopsy without evidence of glomerular injury. Also, interstitial pulmonary fibrosis was determined on computerized tomography, and myeloperoxidase antineutrophil cytoplasmic autoantibody was positive. Consequently, we have considered the main diagnosis as MPA. We did not prefer a standard tubulointerstitial nephritis treatment regimen due to the presence of life-threatening systemic vasculitis. Treatment was established like crescentic glomerulonephritis. Induction therapy consisted of pulse steroid, cyclophosphamide, and plasmapheresis. Unfortunately, severe SARS-CoV-2 infection caused death during induction therapy in this case. CONCLUSIONS: The lack of glomerular injury and solely interstitial inflammation is atypical regarding AAV involvement in the kidney. This diversity might be initially considered as only a simple histological elaboration. However, it is a significant entity for guiding the treatment of AAV.

The presentation, etiologies, pathophysiology, and treatment of pulmonary renal syndrome: A review of the literature.

Pulmonary renal syndrome (PRS) is a constellation of different disorders that cause both rapidly progressive glomerulonephritis and diffuse alveolar hemorrhage. While antineutrophil cytoplasmic antibody associated vasculitis and anti-glomerular basement membrane disease are the predominant causes of PRS, numerous other mechanisms have been shown to cause this syndrome, including thrombotic microangiopathies, drug exposures, and infections, among others. This syndrome has high morbidity and mortality, and early diagnosis and treatment is imperative to improve outcomes. Treatment generally involves glucocorticoids and immunosuppressive agents, but treatment targeted to the underlying disorder can improve outcomes and mitigate side effects. Familiarity with the wide range of possible causes of PRS can aid the clinician in workup, diagnosis and early initiation of treatment. This review provides a summary of the clinical presentation, etiologies, pathophysiology, and treatment of PRS.

Diffuse proliferative glomerulonephritis in a patient with COVID-19 infection.

COVID-19 primarily presents with respiratory involvement. Extrapulmonary manifestations as the sole manifestation also occur although rare. The kidney, being one of the organs with the greatest number of ACE receptors, is usually reported as part of multiorgan involvement. We report an early adolescent boy who presented with nephrotic-nephritic syndrome with severe kidney dysfunction from COVID-19 infection. He had low C3 and undetected antineutrophil cytoplasmic antibodies, antinuclear antibody and antistreptolysin O. Kidney biopsy revealed findings consistent with diffuse proliferative glomerulonephritis with a focal glomerular crescent formation and thin basement nephropathy. Due to the rapidly progressive deterioration of kidney function, he was given pulse methylprednisolone therapy followed by oral prednisone. Complete recovery was documented 12 weeks after the onset of post-infectious glomerulonephritis. The possible pathogenesis of glomerulonephritis in a patient with COVID-19, its differential diagnosis and treatment are discussed.

Glomerulonephritides associated with infections.

Glomerulonephritides associated with infections constitute an important group of diseases. Their occurrence is shifting from children and young people to elderly people. The rates of acute post-streptococcal glomerulonephritis, a condition with a good prognosis, are decreasing, and the rates of glomerulonephritides associated with various bacterial, viral, or parasitic infections, often with a poor prognosis, are increasing. Renal biopsy plays an important role in the diagnostic process. Manifestations of glomerulonephritis can be the initial sign of an occult infection. When evaluating renal biopsy specimens, certain signs may suggest this option, but it cannot be relied on completely. The search for an active infection is warranted in every patient with newly diagnosed glomerulonephritis. Hepatitis B and C serology is always performed, with other investigations depending on individual risk factors, clinical manifestations, and laboratory and histological findings. Failure to follow this rule may have serious consequences, in part because immunosuppressive therapy for glomerulonephritis can worsen the underlying infection and also because the progressive nature of parainfective glomerulonephritis cannot be reversed without eliminating the causative infection. Distinguishing between parainfective and autoimmune glomerulonephritis can be difficult, as there are no major differences in clinical manifestations, laboratory, and sometimes even histological findings. In the setting of the Czech Republic, important diseases include, in particular, staphylococcus infection-associated glomerulonephritis (SAGN) and, in general, infective endocarditis-associated glomerulonephritis, shunt nephritis, and other cases associated with foreign-material infection, such as catheters or electrodes. Among viral diseases, glomerulonephritides associated with the hepatitis B virus, hepatitis C virus, and the SARS CoV-2 virus are of major significance. The treatment of parainfectious glomerulonephritides involves elimination of the causative infection; only in rare cases, a combination of anti-infective treatment and mild immunosuppression can be indicated.

Acute kidney injury after Pfizer COVID-19 vaccine due to crescentic fibrillary glomerulonephritis.

Fibrillary glomerulonephritis (FGN) is a rare glomerular disease manifesting with proteinuria, renal impairment, hematuria, hypertension, and in a very small proportion can be associated with rapidly progressive glomerulonephritis and, rarely, crescent formation. The main modality for diagnosis is kidney biopsy, which ultrastructurally demonstrates randomly arranged non-branching mesangial and glomerular basement membrane (GBM) fibrils and positive staining for the biomarker DNAJB9. The pathogenesis is largely unknown. It was previously hypothesized to represent an immune-complex-type glomerulonephritis, as most cases show IgG4 restriction. We present the first case of crescentic FGN after mRNA Pfizer vaccine for COVID-19. A strong temporal association between vaccination, elevated creatinine, and diffuse crescentic fibrillary process was found. Immunological, neoplastic, and infectious causes were ruled out. We hypothesized that the vaccine stimulated an immune response that triggered crescentic FGN, however, further investigations will be needed to elucidate the direct role of COVID-19 vaccination in crescentic glomerular disease.

Successful Treatment of COVID-19-Related Immune- Complex Glomerulonephritis, Case Report.

Acute kidney injury (AKI) , proteinuria in the nephrotic or subnephrotic range and hematuria might be seen in patients with coronavirus disease 2019 (COVID-19) infection. In this case study we present a 59 years old manwho was diagnosed with immune-complex glomerulonephritis after development of rapidly progressive kidney failure accompanied by pulmonary hemorrhage, 2 months after COVID-19 infection. The patient was hospitalised with the diagnosis of acute kidney injury and nephrotic syndrome. Hemodialysis was performed due to uremic symptoms. Cyclophosphamide, methylprednisolone and plasmapheresis were started. Pathologic examination of kidney biopsy revealed features compatible with immune complex-related acute glomerulonephritis. Cyclophosphamide and plasmapheresis were discontinued , and treatment with 1 mg/kg/day methylprednisolone was continued. Immune-complex glomerulonephritis can be seen following COVID-19 infection. It is important to diagnose this disease entity as soon as possible . Steroidtherapy and other supportive modalities might be sufficient in the treatment.  DOI: 10.52547/ijkd.6527.

Case Report: ANCA-Associated Vasculitis Presenting With Rhabdomyolysis and Pauci-Immune Crescentic Glomerulonephritis After Pfizer-BioNTech COVID-19 mRNA Vaccination.

As the coronavirus disease 2019 (COVID-19) pandemic is ongoing and new variants of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) are emerging, there is an urgent need for COVID-19 vaccines to control disease outbreaks by herd immunity. Surveillance of rare safety issues related to these vaccines is progressing, since more granular data emerge with regard to adverse events of COVID-19 vaccines during post-marketing surveillance. Interestingly, four cases of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) presenting with pauci-immune crescentic glomerulonephritis (GN) after COVID-19 mRNA vaccination have already been reported. We here expand our current knowledge of this rare but important association and report a case of AAV presenting with massive rhabdomyolysis and pauci-immune crescentic GN after Pfizer-BioNTech COVID-19 mRNA vaccination. As huge vaccination programs are ongoing worldwide, post-marketing surveillance systems must continue to assess vaccine safety important for the detection of any events associated with COVID-19 vaccination. This is especially relevant in complex diseases where diagnosis is often challenging, as in our patient with AAV presenting with massive rhabdomyolysis and pauci-immune crescentic GN.

ANCA associated glomerulonephritis in tuberculosis: a paradoxical reaction.

We present a case of antineutrophil cytoplasmic antibodies (ANCA)-associated rapidly progressive glomerulonephritis in the context of treatment of pulmonary tuberculosis (TB). A 42-year-old woman was treated for drug-susceptible pulmonary TB and represented with paradoxical worsening of symptoms and radiological features. She was HIV negative. A severe acute kidney injury with features of glomerulonephritis was evident on admission. Perinuclear ANCA and antimyeloperoxidase antibodies were present in serum and renal biopsy was consistent with ANCA-associated vasculitis. The patient was successfully treated with both antituberculous therapy and immunosuppression (corticosteroids and mycophenolate mofetil) with subsequent clinical improvement and amelioration of renal function. We propose this is the first case that describes the association between paradoxical reactions during TB treatment and ANCA-associated glomerulonephritis.

Newly Diagnosed Glomerulonephritis During COVID-19 Infection Undergoing Immunosuppression Therapy, a Case Report.

During the COVID-19 pandemic, we had a 25 years old male case without any underlying disease or history of autoimmune disease in COVID-19 Clinic, Isfahan, Iran. He presented with arthralgia and weakness so we started COVID-19 therapeutic regimen. In his hospitalization, creatinine increases and abnormalities in random urine sediment was seen. Methylprednisolone and cyclophosphamide were prescribed due to suspected glomerulonephritis. After renal biopsy the diagnose was confirmed as crescentic proliferative glomerulonephritis. The patient also, underwent plasmapheresis and intravenous immunoglobulin injection. He was discharged healthy without development of new pulmonary symptoms despite immunosuppressive treatment.