Tubulointerstitial nephritis with IgG4-positive plasma cell infiltration and tertiary lymphoid tissue in a patient with cryoglobulinemic vasculitis: a case report.

Tertiary lymphoid tissue (TLT) develops at sites of chronic immune stimulation, including infection, autoimmune disease, transplant rejection, and cancer. Recently, TLT has been focused on an indicator for poor renal prognosis in various kidney diseases. In cryoglobulinemic vasculitis (CV), specific glomerular and vascular lesions are seen; however, tubulointerstitial lesions are usually nonspecific. We herein report the case of a 74-year-old man with idiopathic CV with rare tubulointerstitial lesions, such as tubulointerstitial nephritis (TIN) with IgG4-positive plasma cell infiltration and TLT. To our knowledge, this is the first report identifying TLT in the kidney biopsy in a patient with CV. Glucocorticoid improved the renal outcome. The association between CV and TIN with TLT remains unknown.

Streptococcal Infection-related Glomerulonephritis in an Elderly Diabetic Patient Complicated by Hemophagocytic Syndrome and Cytomegalovirus Nephritis.

There has been a significant shift in epidemiology and renal outcomes of infection-related glomerulonephritis (IRGN) in recent years. The renal prognosis of IRGN is often poor in adults, especially in the elderly and diabetics. We herein report an elderly diabetic patient with IRGN due to streptococcal infection complicated by hemophagocytic syndrome and cytomegalovirus nephritis, which is uncommon among non-transplant patients. Infection control and steroids did not recover the patient's renal function. For elderly IRGN patients with diabetes, a further investigation of the most effective treatment for related renal outcomes is needed.

Anti-MDA-5 antibody-positive clinically amyopathic dermatomyositis with rapidly progressive interstitial lung disease treated with therapeutic plasma exchange: A case series.

We present six cases of antimelanoma differentiation-associated gene 5 antibody (anti-MDA5-Ab)-positive clinically amyopathic dermatomyositis (CADM) with rapidly progressive interstitial lung disease (RP-ILD), which is known to have a poor prognosis. The outcomes of these cases are described after treatment with therapeutic plasma exchange (TPE). Clinical and therapeutic data for patients with CADM with RP-ILD were collected retrospectively from medical records. All six patients received early intensive care including high-dose corticosteroids, intravenous cyclophosphamide, and a calcineurin inhibitor, but lung disease and hypoxia became more severe. TPE was performed over a median of 9.5 sessions (range 3-14) per patient, and the median duration from admission to TPE was 23 days. Three patients received combined direct hemoperfusion using a polymyxin B-immobilized fiber column (PMX-DHP) therapy on successive days to manage acute respiratory failure. Four patients survived and two died due to respiratory failure. In the survival cases, ferritin decreased, and ferritin and KL-6 were lower at diagnosis. The patients who died had a higher alveolar-arterial oxygen difference and more severe lung lesions at the time of initiation of TPE. These findings indicate that a combination of conventional therapy and TPE may be useful for improvement of the prognosis of CADM with RP-ILD at the early stage of onset.

Multidisciplinary management of calciphylaxis: a series of 5 patients at a single facility.

Calciphylaxis is a rare and severe disease that manifests with painful skin ulceration and necrosis. Herein, we report five patients of hemodialysis patients with skin biopsy-proven calciphylaxis at a single facility. One patient had undergone parathyroidectomy (PTx) due to severe secondary hyperparathyroidism, four had been treated with vitamin D receptor activators, and two were on warfarin therapy. All patients had hyperphosphatemia, and one had hypercalcemia. The intact parathyroid hormone level at diagnosis was 2 pg/ml in the patient after PTx, while three patients were within the target range. The average period after diagnosis of calciphylaxis was 2 months. Skin lesions were present on the thighs and lower legs in two patients, and on the dorsum of the foot in one patient. In skin biopsy, calcification was found in the arteriolar media in four patients, and calcium (Ca) was deposited in the dermal lesion in one patient. All patients received local cures, surgical debridement, antibiotics to control infectious diseases, and strict control of serum Ca and phosphate. Calcimimetics were used in all patients except one who had undergone PTx one month before, sodium thiosulfate was used in 4 patients, and low Ca dialysate was used in three patients. The average follow-up period was 7.4 months. Four patients were cured, and one died due to infection. We suggest that multidisciplinary management for infectious diseases, surgical debridement, strict control of mineral and bone markers from the early stage, and elimination of risk factors may improve the course of calciphylaxis, which is a life-threatening disease.

Membranous nephropathy caused by rheumatoid arthritis.

Membranous nephropathy (MN) caused by disease-modifying antirheumatic drugs is relatively common in patients with rheumatoid arthritis (RA). However, MN rarely occurs due to RA itself. We describe a 61-year-old woman with RA who showed nephrotic syndrome. She was admitted because of systemic edema and severe arthritis. She had a long history of RA successfully treated with methotrexate (MTX), but discontinued all treatments 4 years before hospitalization. She had never been treated with bucillamine or gold. Laboratory test results were positive for anti-cyclic citrullinated peptide antibody and negative for anti-nuclear antibody. Renal pathologic findings were compatible with MN. Immunofluorescence microscopy showed IgG, IgA, κ, λ, and C3 along the glomerular capillary wall, whereas deposition of IgM or C1q was not detected. In terms of the IgG subclasses, only IgG2 findings were positive. Results for glomerular antigen and serum antibody for M-type phospholipase A2 receptor and thrombospondin type 1 domain-containing 7A were negative. HLA type did not include the HLA-DQA1 gene that is a concern in primary MN (PMN). She responded to intensive immunosuppressive therapy consisting of prednisolone, tacrolimus, and MTX with a parallel reduction of proteinuria. Based on assessments for differentiating PMN from secondary MN (SMN), the diagnosis of the present case was incompatible with PMN. Taken together, we consider that SMN in the present case was due to RA itself rather than drug-induced MN.