Apolipoprotein E regulates primary cultured human mesangial cell proliferation.

BACKGROUND: The role of apolipoprotein (apo) E in kidney disease is still unclear. Animal studies have been performed, but it is doubtful if the conclusions are applicable to human beings. The objective of this study was to determine how apo E acts on human kidneys using primary cultured normal human mesangial cells (NHMCs) rather than animals used in previous studies. METHODS: apo E and its isoforms E2, E3 and E4, or combinations with apo B were cocultured with primary NHMCs in serum-free medium. Premix WST-1 Cell Proliferation Assay System and DNA-Prep Reagent System were used to measure the proliferation and apoptosis of NHMCs, respectively. RESULTS: (1) apo E itself increased NHMC proliferation at 24 h of culture, while it inhibited this proliferation after 48 h. (2) At 72 h of culture, apo E alone inhibited NHMC proliferation at concentrations higher than 0.78 microg/ml in concentration-dependent manner. (3) When co-cultured with both apo E and apo B, NHMC proliferation was higher than that with apo E alone and lower than that with apo B alone. (4) At 72 h of culture, apo E2, E3 and E4 inhibited NHMC proliferation at different intensities, with no proliferative effect observed. (5) Neither apo E nor apo B caused NHMC apoptosis. CONCLUSION: apo E regulates primary NHMC proliferation by (1) inhibiting NHMC proliferation or reducing NHMC proliferation induced by apo B, which implies that apo E has a protective effect on the kidney, and (2) increasing the proliferation under certain conditions.

Breast cancer with nephrotic syndrome: report of two cases.

We report two cases of women found to have breast cancers within a few months of being diagnosed with nephrotic syndrome. Case 1 was a 53-year-old Japanese woman in whom breast cancer was diagnosed 14 months after the onset of nephrotic syndrome. The histological diagnosis was invasive ductal carcinoma with no lymph node metastasis. We performed a modified radical mastectomy, after which the proteinuria and hypoproteinemia resolved almost completely, and the patient has been disease-free for 5 years since. Case 2 was a 61-year-old Japanese woman in whom breast cancer was diagnosed 2 months after the onset of membranous nephropathy. We performed a modified radical mastectomy and the histological diagnosis was invasive ductal carcinoma with marked lymphatic vessel permeation and involvement of five axillary lymph nodes. Proteinuria and hypoproteinemia did not resolve postoperatively and there is a high possibility of remnant or recurrent cancer. To our knowledge, there are only four other reported cases of paraneoplastic membranous nephropathy complicating breast cancer. However, we speculate that the postoperative resolution of nephrotic syndrome might be a measure of cancer control.

Fabry disease: detection of undiagnosed hemodialysis patients and identification of a "renal variant" phenotype.

BACKGROUND: Fabry disease is an X-linked recessive lysosomal storage disease resulting from deficient alpha-galactosidase A (alpha-Gal A) activity. Renal failure is a major debilitating complication in classically affected males. To determine if this disorder is underdiagnosed in patients with end-stage renal disease (ESRD), the frequency of unrecognized males with Fabry disease on chronic hemodialysis was determined. METHODS: Plasma alpha-Gal A activity was measured in 514 consecutive males with ESRD on hemodialysis. Patients with low alpha-Gal A activity were evaluated clinically and their alpha-Gal A mutations were determined. RESULTS: Six (1.2%) of 514 hemodialysis patients had low plasma alpha-Gal A activities and a previously identified (E66Q, A97V, M296I) or novel (G373D) missense mutation. At ages 30 to 68 years, five patients lacked the classic manifestations of angiokeratoma, acroparesthesias, hypohidrosis, and ocular opacities, while the sixth lacked angiokeratoma and ocular changes. Five had left ventricular hypertrophy (LVH). CONCLUSION: The clinical spectrum of Fabry disease includes a "renal variant" phenotype in patients without classic symptoms who develop ESRD. Affected males undergoing hemodialysis or renal transplantation can be readily diagnosed by plasma alpha-Gal A assays. These patients and their family members may benefit from enzyme replacement therapy for the later, life-threatening cardiovascular and cerebrovascular complications of Fabry disease.