Characteristics of IgA nephropathy in advanced-age patients.

PURPOSE: The susceptible age for IgA nephropathy (IgAN) is <30 years. However, IgAN sometimes develops in people aged >60 years, and its characteristics remain unknown. METHODS: We divided 600 IgAN patients into three groups: advanced-age group (AAG, n=31, ≥60 years); middle-aged group (MAG, n=162, 40-59 years); and young-aged group (YAG, n=407, 20-39 years). We analyzed clinical and histological background, renal outcome, and risk of progression. RESULTS: In the AAG, mean arterial pressure (MAP) and the number of hypertensive patients were significantly higher than in the YAG. Total protein, serum albumin, and estimated glomerular filtration rate were significantly lower, and blood urea nitrogen, proteinuria, and N-acetyl-ß-D-glucosaminidase were significantly higher in the AAG than in MAG and YAG. In histological findings, interstitial fibrosis/tubular atrophy by Oxford classification and arteriosclerosis were more severe in the AAG than the in YAG. Renal survival rate analyzed by Kaplan-Meier method was significantly lower in the AAG (22.9%/19 years in the AAG vs. 69.2 and 84.9%/20 years in the MAG and YAG, p<0.0001). The patients who progressed to end-stage renal disease (ESRD) in the AAG had higher MAP and more severe proteinuria compared with the patients who did not progress to ESRD in the AAG. CONCLUSIONS: The characteristics of IgAN in advanced-age were lower renal function, high levels of proteinuria, severe interstitial change, and arteriolosclerosis caused by glomerulopathy and concomitant diseases, such as hypertension, dyslipidemia, and hyperuricemia. Prognosis was poor, and >70% developed ESRD within 20 years.

Renal infarction in a patient with pulmonary vein thrombosis after left upper lobectomy.

A 43-year-old male experienced renal infarction (RI) following left upper lobectomy for lung cancer. The patient complained of acute-onset severe left flank pain on the 14th postoperative day. A contrast-enhanced computed tomography (CT) of the abdomen revealed RI by a large wedge-shaped defect in the left kidney. A chest CT scan located the thrombus in the stump (a blind-ended vessel) of the left superior pulmonary vein. Therefore, thromboembolic RI caused by pulmonary vein thrombosis was suspected. Anticoagulation therapy was initiated with heparin and warfarin to treat RI and to prevent further embolic episodes. Two months later, pulmonary vein thrombosis had resolved without the appearance of additional peripheral infarction. This case emphasizes the need to consider thrombus in the stump of the pulmonary vein as a cause of RI.

Prognosis in IgA nephropathy: 30-year analysis of 1,012 patients at a single center in Japan.

BACKGROUND: Little is known about the long-term prognosis of patients with IgA nephropathy (IgAN). METHODS: This retrospective cohort analysis evaluated clinical and histological findings at the time of renal biopsy, initial treatment, patient outcomes over 30 years, and risk factors associated with progression in 1,012 patients diagnosed with IgAN at our center since 1974. RESULTS: Of the 1,012 patients, 40.5% were male. Mean patient age was 33±12 years and mean blood pressure was 122±17/75±13 mmHg. Mean serum creatinine concentration was 0.89±0.42 mg/dL, and mean estimated glomerular filtration rate (eGFR) was 78.5±26.2 ml/min/1.73 m2. Mean proteinuria was 1.19±1.61 g/day, and mean urinary red blood cells were 36.6±35.3/high-powered field. Histologically, mesangial hypercellularity was present in 47.6% of patients, endothelial hypercellularity in 44.3%, segmental sclerosis in 74.6%, and tubular atrophy/interstitial fibrosis in 28.8% by Oxford classification. Initial treatment consisted of corticosteroids in 26.9% of patients, renin-angiotensin-aldosterone system inhibitor in 28.9%, and tonsillectomy plus steroids in 11.7%. The 10-, 20-, and 30-year renal survival rates were 84.3, 66.6, and 50.3%, respectively. Tonsillectomy plus steroids dramatically improved renal outcome. Cox multivariate regression analysis showed that higher proteinuria, lower eGFR, and higher uric acid at the time of renal biopsy were independent risk factors for the development of end stage renal disease (ESRD). CONCLUSIONS: IgAN is not a benign disease, with about 50% of patients progressing to ESRD within 30 years despite treatment.

Statins stabilize the renal function of IgA nephropathy.

BACKGROUND: The renoprotective pleiotropic effect of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) has recently been reported by several investigators. However, the effect of statins on IgA nephropathy (IgAN) is still unknown. METHODS: We selected 24 IgAN patients who had newly started statin therapy and were not treated with steroids and immunosuppressive agents during the observation period. We analyzed and compared clinical findings 1 year before and after treatment. RESULTS: Mean age was 50.5 ± 9.91 years and mean blood pressure was 90.9 ± 10.8 mmHg. Renal function was slightly deteriorated, serum creatinine was 1.03 (0.71-1.24) mg/dL and estimated glomerular filtration rate (eGFR) was 55.8 ± 22.8 mL/min. Lipid metabolism was poorly controlled [total cholesterol 247.7 ± 35.7 mg/dL, low-density lipoprotein cholesterol 151.5 (140.8-172.8) mg/dL, and triglyceride 163.0 (126.3-243.8) mg/dL]. Mild urinary abnormality was observed [proteinuria: 0.50 (0.22-1.29) g/g creatinine, urinary red blood cells 1.0 (0.2-5.0) per high power field]. After 1 year of statin treatment, lipid control was significantly better than at baseline. Proteinuria was not significantly decreased but renal function was improved. eGFR changed from a -5.9% decrease to a 2.4% increase (p = 0.0098). CONCLUSION: Our results indicated that statins stabilized the renal function of IgAN patients independent of their reduction of proteinuria.

IgG4-related tubulointerstitial nephritis and lymphadenopathy after therapy for malignant lymphoma.

We report a middle-aged Japanese man who had a past history of malignant lymphoma with tubulointerstitial nephritis (TIN) presenting a high serum immunoglobulin G4 (IgG4) concentration and bilateral kidney enlargement and swelling of many lymph nodes. Although lymph node biopsy was not evident of a recurrence of lymphoma, kidney biopsy showed prominent infiltration of IgG4-positive plasma cells in a tubulointerstitial lesion but not in glomeruli. We made a diagnosis of IgG4-related TIN and lymphadenopathy; administration of oral prednisolone improved his physical and laboratory parameters. This is the first report of a case of IgG4-related TIN and lymphadenopathy after therapy for malignant lymphoma.