Immunoglobulin G deposition on proximal tubules and the tubular basement membrane in acute tubular injury complicated with focal segmental glomerulosclerosis (FSGS): A possible prediction tool for subclinical FSGS.

Immunofluorescent deposition of immunoglobulin G (IgG) in the tubular basement membrane (TBM) has been evaluated in the diagnosis of various diseases; however, few studies have investigated the immunofluorescence of acute tubular injury (ATI). Herein, we attempted to clarify IgG expression in the proximal tubular epithelium and TBM in ATI due to various causes. Patients with ATI with nephrotic-range proteinuria, including focal segmental glomerulosclerosis (FSGS, n = 18) and minimal change nephrotic syndrome (MCNS, n = 8), ATI with ischemia (n = 6), and drug-induced ATI (n = 7), were enrolled. ATI was evaluated by light microscopy. CD15 and IgG double staining and IgG subclass staining were performed to evaluate immunoglobulin deposition in the proximal tubular epithelium and TBM. IgG deposition was identified in the proximal tubules only in the FSGS group. Furthermore, IgG deposition in the TBM was observed in the FSGS group showing severe ATI. IgG3 was predominantly deposited by the IgG subclass study. Our results indicate that IgG deposition in the proximal tubular epithelium and TBM suggests the leaking of IgG from the glomerular filtration barrier and its reabsorption by proximal tubules, which may predict disruption of the glomerular size barrier, including subclinical FSGS. FSGS with ATI should be included as a differential diagnosis when IgG deposition in TBM is observed.

A Rare Case of Blindness Caused by Syphilis with Malignant Hypertensive Nephropathy.

The number of patients with syphilis has been rapidly increasing. Without treatment, syphilis can damage various organs and become life-threatening. We herein report a 29-year-old woman diagnosed with neurosyphilis, acute hydrocephalus, syphilitic uveitis combined with hypertensive retinopathy, and malignant hypertensive nephropathy. To our knowledge, this is the first report of syphilis complicated with malignant hypertensive nephropathy proven by a renal biopsy. Neurosyphilis was successfully treated with intravenous penicillin G, and severe hypertension subsequently resolved. However, delayed medical examinations and complications of syphilitic uveitis and hypertensive retinopathy resulted in irreversible visual loss. To prevent irreversible organ damage, early treatment is essential.

A long-term survival case of Erdheim-Chester disease on maintenance hemodialysis.

Erdheim-Chester disease, a rare non-Langerhans histiocytosis, involves multiple organs, including kidney. Renal dysfunction sometimes occurs, and is attributed to ureteral obstruction and renal artery stenosis by histiocytic infiltration. However, to our knowledge, case reports of end-stage renal disease requiring renal replacement therapy due to Erdheim-Chester disease are very few. Here, we report a 69-year-old woman who was diagnosed with Erdheim-Chester disease 10 years ago. She had multiple organ involvement, such as bone, skin, heart, pituitary gland, kidney, and retroperitoneum. She had been treated with interferon-alpha, but discontinued after 2 years due to depression and repeated infection. She did not desire treatment with other drugs, so we continued supportive care. Her renal function gradually deteriorated, and hemodialysis was initiated 4 years ago. Subsequently, she is still doing well without any major symptoms. This report describes an unusual case of Erdheim-Chester disease requiring maintenance hemodialysis that longer prognosis than expected was obtained regardless of multiple organ involvement and no specific treatment after interferon-alpha cessation.

Nephrotic syndrome with acute kidney injury due to focal segmental glomerulosclerosis following long-term treatment with minodronate.

Although bisphosphonates are well known to cause kidney disease, there are very few published cases of focal segmental glomerulosclerosis (FSGS) following treatment with minodronate. Here we report the case of an 86-year-old woman who developed acute kidney injury and nephrotic syndrome after receiving monthly oral minodronate for 24 months. Kidney biopsy revealed cellular variant FSGS. Treatment was initiated with the discontinuation of minodronate followed by intravenous methylprednisolone pulse and prednisolone at 35 mg/day. Subsequently, the patient's renal function gradually worsened, requiring initiation of hemodialysis. However, renal function and proteinuria improved markedly and hemodialysis was withdrawn 1 month after the initiation of steroid therapy. This is, to our knowledge, the first published case of FSGS induced by long-term use of minodronate, and also the first case of cellular variant FSGS induced by bisphosphonates although collapsing variant of FSGS is commonly caused by bisphosphonates. Our study indicates that patients on bisphosphonates should be closely monitored for proteinuria and renal impairment, regardless of the type of bisphosphonate.

Long-Term Prognosis of Hyperferritinemia Induced by Intravenous Iron Therapy in Patients Undergoing Maintenance Hemodialysis: A 10-Year, Single-Center Study.

Optimal ferritin level in hemodialysis patients between Japan and other countries is controversial. Long-term side effects of iron supplementation in these patients remain unclear. We aimed to elucidate whether past hyperferritinemia in hemodialysis patients was associated with high risk of death and cerebrovascular and cardiovascular diseases (CCVDs). This small retrospective cohort study included approximately 44 patients unintentionally supplemented with excessive intravenous iron. A significantly higher risk of CCVDs was observed in patients with initial serum ferritin levels ≥1000 ng/mL than in the remaining patients. High ferritin levels slowly decreased to <300 ng/mL in a median of 24.2 (10.5-46.5) months without treatment. However, compared with the remaining patients, only patients whose ferritin levels did not decrease to <300 ng/mL steadily had a significantly higher risk of all-cause death (hazard ratio, 9.6). Long-term hyperferritinemia due to intravenous iron therapy is a risk factor for death in maintenance hemodialysis patients. For a prolonged better prognosis, intravenous iron should be carefully administered so as to avoid hyperferritinemia in patients with hemodialysis.