Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant condition characterized by monoclonal paraprotein production, with IgM and non-IgM variants. While IgM MGUS is often associated with lymphoid neoplasms, non-IgM MGUS can progress to multiple myeloma. Comorbidities include bone mineral density loss and renal complications, such as monoclonal gammopathy of renal significance (MGRS) and peripheral neuropathy. Cardiovascular risks are also elevated. Despite its significance, MGUS often goes undiagnosed due to its asymptomatic nature and overlap with age-related comorbidities. We present a case of IgM MGRS manifesting as rapidly progressive glomerulonephritis, highlighting the diagnostic challenges and clinical implications of MGUS-associated complications.

This case report discusses the management of anti-neutrophil cytoplasmic antibodies (ANCA)-negative rapid progressive glomerulonephritis (RPGN) in a 68-year-old man with a complex medical history, presenting with fatigue, edema, and acute renal failure. Despite the absence of positive biomarkers for specific RPGN types, the clinical progression suggested microscopic polyangiitis, leading to intensive immunosuppressive therapy with cyclophosphamide and rituximab. The patient\'s condition was further complicated by the coexistence of nephritic and nephrotic syndromes, requiring nuanced management strategies, including prolonged hemodialysis. After initial treatment failure, remission was eventually achieved, allowing cessation of dialysis and significant recovery of renal function. This case highlights the challenges of diagnosing and managing ANCA-negative RPGN, particularly the importance of a tailored, dynamic approach to treatment in resource-limited settings. The recovery observed underscores the potential for renal function improvement even after prolonged periods of intensive therapy, reinforcing the need for persistence and adaptability in managing complex RPGN cases.

IgA nephropathy (IgAN) is a fairly common association with alcoholic liver disease. However, IgA vasculitis (IgAV) is quite an uncommon association with alcoholic liver cirrhosis and only a handful of cases have been reported in literature. Secondary IgAN usually presents in a docile manner, progressing slowly in about 5-25 years. It is usually responsive to steroid therapy, very rarely progressing to End-Stage Renal Disease. Here, we present a man in his late 50s, a known hypertensive and alcohol related liver-cirrhotic, who presented to our hospital with rash and rapidly progressive renal failure (RPRF). He was diagnosed with IgA nephritis with IgA vasculitis (IgAVN). His diagnosis was confirmed with skin and renal biopsy. He was started on renal replacement therapy for his renal failure and began oral steroid therapy. After administration of steroid therapy for 6 months, the patient recovered and was dialysis independent with stable renal parameters.

BACKGROUND: The concomitant occurrence of membranous nephropathy and anti-glomerular basement (anti-GBM) disease has been previously described but is extremely rare. However, delayed recognition or misdiagnosis leads to delayed treatment, resulting in worse renal and patient outcomes.
METHODS: We present 3 patients with rapidly progressive glomerulonephritis (RPGN), anti-GBM and serum-positive M-type phospholipase A2 receptor (anti-PLA2R) antibody. Renal biopsies revealed PLA2R-associated membranous nephropathy with anti-GBM glomerulonephritis. We analyzed the clinical and pathological characteristics and discussed that the correct diagnosis of membranous nephropathy with anti-GBM should rely on a combination of renal biopsy findings and serological testing. Despite aggressive treatment, one patient received maintenance hemodialysis, one patient progressed to CKD 3 stage, and the other patient died of cerebral infarction.
CONCLUSIONS: The simultaneous occurrence of membranous nephropathy and anti-GBM disease is extremely rare. The correct diagnosis of membranous nephropathy with anti-GBM relies on a combination of renal biopsy findings and serological testing. Early diagnosis is needed to improve the renal dysfunction.

A 75-year-old woman, with hypertension and atrial fibrillation but no prior renal history, presented to the hospital for chest discomfort and dyspnea. She was found to be in acute renal failure, with a serum creatinine of 5.1, increased from a baseline of 0.9, and urine analysis revealing proteinuria and hematuria with dysmorphic red blood cells. Subsequent work up was significant for positive perinuclear antineutrophil cytoplasmic antibody (p-ANCA) and myeloperoxidase antibodies. She underwent a renal biopsy, which revealed necrotizing crescents in 12 of 14 glomeruli, and she was diagnosed with rapidly progressive glomerulonephritis due to microscopic polyangiitis. Despite aggressive treatment with plasmapheresis, high-dose prednisone, and rituximab infusions, renal function worsened, and she required initiation of hemodialysis. She was ultimately discharged after a three-week admission, with plans to continue rituximab infusions and three times weekly hemodialysis in the outpatient setting. Due to her poor response to traditional therapies, initiation of a new targeted immunomodulator known as avacopan, a complement 5a receptor antagonist, was considered. Such targeted immunomodulators are also of particular interest as possible ways to reduce the risk of severe infection associated with current broad immunosuppressive modalities. In addition, when used in place of steroids, they reduce the morbidity associated with cumulative glucocorticoid toxicity. For patients with ANCA-associated vasculitis refractory to standard therapies, targeted immunomodulators such as avacopan should be considered as alternative or adjunct therapy.

BACKGROUND: Crescentic glomerulonephritis with syphilis infection is rare, and the mechanism underlying the formation of glomerular capillary wall damage-induced crescent has not been elucidated.
METHODS: A 62-year-old Japanese male showed edema, eruption, and rapid deterioration of the renal function after an acute syphilis infection. A renal biopsy showed crescentic glomerulonephritis with C3 deposition in the glomerular capillary wall, and immunostaining for anti-Treponema pallidum antibody was weakly positive in some interstitium and one glomerulus. Electron microscopy revealed the presence of string-shaped structures in the glomerular capillary walls. After treatment with penicillin followed by prednisolone, the renal function and urinary abnormalities, including Treponema pallidum protein, disappeared.
CONCLUSIONS: Crescentic glomerulonephritis associated with syphilis showed a string-shaped deposition in the glomerular capillary and urinary Treponema pallidum protein excretion, and was effectively treated with penicillin and prednisolone.

Granulomatous polyangiitis (GPA) is a rare autoimmune disease that can involve multiple systems throughout the body, including the ear, nose, upper and lower respiratory tracts. It is classified as an antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. Telitacicept is a novel recombinant fusion protein targeting B-lymphocyte stimulator (BLyS). Telitacicept can inhibit the development and maturation of abnormal B cells by blocking BLyS, and inhibit the production of antibodies by abnormal plasma cells by blocking APRIL (A proliferation-inducing ligand), which is expected to become a new drug for the treatment of GPA. We report a 64-year-old man diagnosed at our hospital with GPA involving multiple systems including kidneys, lungs, nose and ears. Renal involvement was severe, with a clinical characteristic of rapidly progressive glomerulonephritis and a pathologic manifestation of crescentic nephritis with plasma cell infiltration. The patient was treated with hormones, immunoglobulins and cyclophosphamide (CYC) with the addition of telitacicept and a rapid reduction in hormone dosage. The patient\'s renal function improved significantly within a short period of time, and his hearing and lung lesions improved significantly. At the same time, he did not develop serious infections and other related complications. Our report suggests that short-term control of the patient\'s conditions is necessary in GPA patients with organ-threatening disease. Telitacicept combined with CYC and glucocorticoids may be an induction therapy with safety and feasibility. However, more clinical trials are needed to validate the efficacy and safety of the therapeutic regimen.

A 79-year-old man presented with dyspnea upon exertion, marked renal dysfunction, proteinuria, and hematuria. He was diagnosed with rapidly progressive glomerulonephritis. Serological tests were positive for MPO-ANCA, PR3-ANCA, and anti-GBM antibodies. Since the anti-GBM antibody titer was significantly higher than the ANCA titer and the renal dysfunction was severe, we initially assumed anti-GBM disease and started treatment. Due to poor general condition, a definitive diagnosis could not be made by renal biopsy. Corticosteroid therapy, plasmapheresis, and cyclophosphamide treatment were performed. However, renal function did not improve, and hemodialysis was required. He died of sepsis during treatment. An autopsy was performed with the consent of the family. Renal pathological examination revealed fibrocellular crescent formation in the glomeruli. Immunofluorescence revealed no major deposition in the glomeruli, suggesting ANCA-associated nephritis but not anti-GBM disease. Gross pathological findings of the abdominal aorta showed that a part of the artificial blood vessel had formed a pseudoaneurysm and abscess. There is no evidence of inflammatory cell infiltration or vasculitis in the alveoli. Pathological findings in the other organs did not suggest vasculitis. The renal prognosis of this case could have been improved with appropriate treatment if early diagnosis by renal biopsy had been made. There have been case reports of triple-seropositive rapid progressive glomerulonephritis (RPGN). We report a rare autopsy case of triple-seropositive RPGN.

Antiglomerular basement membrane (anti-GBM) disease is a rare, small-vessel vasculitis that affects the capillary beds of the kidneys and lungs. Although exceedingly rare, several case reports have described anti-GBM disease with a concurrent cancer diagnosis, suggesting a possible correlation between these 2 conditions. Herein, we describe the first known case to our knowledge of a woman in her early 60s with simultaneous anti-GBM disease and clear cell renal cell carcinoma, in which the tumor was thought to have been the substrate for anti-GBM disease. We believe that renal cell carcinoma may have contributed to the production of anti-GBM autoantibodies and, thus, anti-GBM disease. The concurrence of these 2 conditions complicated the treatment of the patient, who was hemodialysis-dependent at the time of hospital discharge. This report highlights the importance of considering anti-GBM disease as a potential diagnosis in patients with acute kidney failure, and how important it is to identify both clear cell renal cell carcinoma and anti-GBM disease at an early stage to improve outcomes.

Anti-GBM disease is a rare, life-threatening small vessel vasculitis caused by circulating anti-GBM antibodies resulting to rapidly progressive glomerulonephritis and/or pulmonary haemorrhage. The gold standard for the diagnosis is the renal biopsy with the pathognomonic finding of linear deposition of IgG along the glomerular capillaries. Early diagnosis and intervention are key determinants of the response to therapy and long-term prognosis of these patients. However, during COVID-19 pandemic recognizing a pulmonary-renal syndrome caused by autoimmune diseases has become challenging. Herein, we aimed to describe a rare case of anti-GBM disease with pulmonary haemorrhage and rapidly progressive glomerulonephritis in a young man in a tertiary referral hospital in Greece, while COVID-19 pandemic was at its peak. Although the patient presented high level of creatinine and crescents, the early diagnosis and start of treatment resulted to favourable renal prognosis.