losartan-potassium and Glomerulonephritis--IGA

Topics: Anemia; Antibody Formation; Endothelium, Vascular; Erythropoietin; Glomerulonephritis, IGA; Humans; Immunity, Cellular; Kidney; Kidney Failure, Chronic; Research; Singapore

The infusion of low-dose dopamine is normally associated with an increase in creatinine clearance, thereby allowing one to assess renal functional reserve. Increased renal blood flow is also associated with a reduction in erythropoietin (EPO) levels.. We evaluated the use of dopamine infusion in subjects with IgA nephropathy to determine if these functional changes correlate with risk factors for progression and compared this to the renal biopsy findings.. Changes in creatinine clearance and EPO levels were determined in 46 non-nephrotic IgA patients with relative preserved renal function after the infusion of low dose dopamine. Control subjects (n = 15) were evaluated using similar protocols.. Subjects with IgA nephropathy could be separated into those who showed a fall in EPO levels (n = 24) and those who showed no change or a rise in EPO levels (n = 22). Subjects showing the expected fall in EPO demonstrated a higher increase in creatinine clearance, similar to that observed in control subjects. Most importantly, subjects who showed a fall in EPO had less proteinuria, less N-acetyl-β-D-glucosaminidase excretion, lower serum uric acid, blood pressure, and less features of metabolic syndrome despite similar inflammation and fibrosis on biopsy as compared to the others.. A decrease in EPO in response to dopamine is associated with a clinical phenotype that is less likely to develop progressive renal disease. These studies suggest that a fall in EPO in response to dopamine likely reflects preserved tubulointerstitial function that cannot be assessed by renal biopsy alone.

Topics: Adult; Case-Control Studies; Creatinine; Disease Progression; Dopamine; Erythropoietin; Female; Glomerulonephritis, IGA; Humans; Kidney; Lipids; Male; Risk Factors; Uric Acid

Elevated serum uric acid experimentally stimulates renal vasoconstriction and activation of the renin- angiotensin system and consequently modulates erythropoietin (EPO) production. We used a dopamine-induced glomerular filtration response test (DIR) to assess whether elevated uric acid is associated with dopamine response and EPO levels in IgA patients.. In 46 non-nephrotic IgA patients (age: 33.7 ± 8.9 years) and 15 controls (age: 33.5 ± 6.9 years) with a glomerular filtration rate of 86.7 ± 17.4 and 118.1 ± 17.2 ml/min, respectively, renal vascular function was estimated based on DIR. DIR was measured using two 120-min creatinine clearances (before and after i.v. administration of 2 μg/kg/min dopamine) and at the same points EPO was measured. Uric acid, cholesterol, triglycerides, urinary uric acid and N-acetyl-β-D-glucosaminidase were measured.. Basal EPO was the same in IgA patients and controls (13.5 ± 9.5 vs. 10.6 ± 4.3 mU/ml, respectively; NS); however, EPO correlated with uric acid clearance in IgA patients but not in controls (r = 0.45, p < 0.002 vs. r = 0.25, p < 0.361, respectively), and DIR tended to be lower in IgA nephropathy (p < 0.06). A more pronounced slope between EPO and DIR as well as lower DIR/EPO was found in IgA patients.. These results are consistent with greater renal vasoconstriction in IgA nephropathy that would stimulate EPO and reduce urate clearance.

Topics: Adult; Biomarkers; Dopamine; Erythropoietin; Female; Glomerular Filtration Rate; Glomerulonephritis, IGA; Humans; Male; Uric Acid; Vasoconstriction; Young Adult

Anti-erythropoietin antibodies usually cross-react with all kinds of recombinant erythropoietins; therefore, erythropoiesis-stimulating agent (ESA)-induced pure red-cell aplasia (PRCA) is not rescued by different ESAs. Here, we present a case of ESA-induced PRCA in a 36-yr-old woman with chronic kidney disease, whose anemic condition improved following reintroduction of darbepoetin-α. The patient developed progressive, severe anemia after the use of erythropoietin-α. As the anemia did not improve after the administration of either other erythropoietin-α products or erythropoietin-β, all ESAs were discontinued. Oxymetholone therapy failed to improve the transfusion-dependent anemia and a rechallenge with ESAs continuously failed to obtain a sustained response. However, her anemia improved following reintroduction of darbepoetin-α at 3 yr after the initial diagnosis. Interestingly, anti-erythropoietin antibodies were still detectable, although their concentration was too low for titration. In conclusion, darbepoetin-α can improve ESA-induced PRCA when the anti-erythropoietin antibody titer declines and its neutralizing capacity is lost.

Topics: Adult; Anemia; Antibodies; Bone Marrow Cells; Darbepoetin alfa; Drug Hypersensitivity; Erythropoietin; Female; Glomerulonephritis, IGA; Hematinics; Humans; Kidney Failure, Chronic; Oxymetholone; Recombinant Proteins; Red-Cell Aplasia, Pure

Topics: Adult; Chronic Disease; Disease Progression; Erythropoietin; Female; Glomerulonephritis, IGA; Humans; Kidney; Pregnancy; Pregnancy Complications; Pregnancy Outcome; Recombinant Proteins; Renal Dialysis

In 2002, the Joint Committee of the Special Study Group on Progressive Glomerular Diseases, Ministry of Health, Labor and Welfare of Japan newly revised the clinical guidelines for IgA nephropathy (Sakai et al.: Jpn J Nephrol 37:417-421, 1995; Tomino and Sakai: Clin Exp Nephrol, 7, 93-97, 2003). The prognostic stages were classified into four groups: the good prognosis group (Group I), relatively good prognosis group (Group II), relatively poor prognosis group (Group III), and poor prognosis group (Group IV). The relationship between the levels of Hb, Ht, and RBC in peripheral blood and the renal prognostic stages was determined in 62 patients with IgA nephropathy in the present study. The mean levels of Hb, Ht, and RBC were significantly lower in Group IV than in Group I (P<0.05). However, there were no significant changes in the levels of serum creatinine (s-Cr) or creatinine clearance (CCr) among these four groups. It appears that the levels of Hb, Ht, and RBC in peripheral blood may be important clinical parameters for the evaluation of prognostic stages in patients with IgA nephropathy.

Topics: Adolescent; Adult; Aged; Anemia; Creatinine; Erythrocyte Count; Erythropoietin; Female; Glomerulonephritis, IGA; Hematocrit; Hemoglobins; Humans; Male; Middle Aged; Prognosis

Tumoral calcinosis is a rare form of soft tissue calcifications, initially described as an idiopathic condition, which could occur in uremic patients. Despite its distinct clinical and morphologic presentations, the underlying pathogenesis is unknown. We present a dialysis patient who developed tumoral calcinosis over the right shoulder after receiving a misplaced injection of human recombinant erythropoietin probably into the periarticular tissue. This case serves as an example highlighting the importance of periarticular inflammatory reaction in precipitating the development of the lesion in predisposed patients.

Topics: Administration, Oral; Adult; Bursa, Synovial; Calcinosis; Calcium; Calcium Carbonate; Dialysis Solutions; Erythropoietin; Female; Glomerulonephritis, IGA; Humans; Hypercalcemia; Hyperplasia; Injections, Intramuscular; Kidney Failure, Chronic; Leukocytosis; Parathyroid Hormone; Patient Compliance; Peritoneal Dialysis, Continuous Ambulatory; Radiography; Recombinant Proteins; Shoulder Joint

Recent reports describe that erythropoietin (Epo) is produced by peritubular interstitial fibroblast-like cells in response to a hypoxic stimulus. We studied serum Epo levels as a possible marker of tubulointerstitial damage in the progression of IgA nephropathy (IgAN), in comparison with urinary (u-) levels of N-acetyl-beta-D-glucosaminidase (NAG), which is mainly derived from proximal tubular cells and is used as a marker of tubular damage.. Thirty-eight patients with IgA nephropathy (IgAN) with relatively preserved renal function (serum creatinine: sCr, 0.5-2.2 mg/dl) were examined. The severity of glomerulosclerosis and interstitial fibrosis of the renal biopsy tissue was expressed by semiquantitative grading scores. Clinical parameters including serum creatinine (sCr), blood pressures, and 24-h proteinuria levels were obtained at the renal biopsy. Epo was measured by a radioimmunoassay (RIA) of sera obtained in the morning and u-NAG was measured by colorimetric method of 24-h urine samples.. The mean Epo level of the patients (17.7+/-6.3 mU/ml) was not different from the control level (19.3+/-3.7 mU/ml). There were no significant correlations between Epo levels and red blood cell (RBC) counts, haematocrit (Hct), or haemoglobin (Hb) levels. The mean u-NAG level of the patients (6.7+/-6.2 U/gCr) was significantly higher than the control level (1.9+/-0.5 U/gCr). There was an inverse quantitative correlation between Epo and u-NAG levels in the patients (P<0.02). The u-NAG levels showed quantitative positive correlations with sCr (P<0.001), u-proteins (P<0.001), systolic (SBP) (P<0.001), and diastolic blood pressures (DBP) (P<0.05). Conversely, Epo levels were inversely correlated with sCr, SBP and DBP (each P<0.05). The patients with higher u-proteins (>2.0 g/day) showed significantly decreased Epo levels (P<0.05) than those with lower u-proteins (<2.0 g/day). The both scores of glomerulosclerosis and interstitial fibrosis were positively correlated with the u-NAG levels (each P<0.001), but were not correlated with the Epo levels.. The significant correlation between u-NAG and serum Epo levels suggests that tubular damage and interstitial cell dysfunction are associated each other in the progression of IgAN. Serum Epo levels bearing inverse correlations with sCr, blood pressure levels and heavy proteinuria seem to reflect clinical severity of IgAN, whereas u-NAG can be more useful progression marker of IgAN bearing correlations with both clinical and histological findings.

Topics: Acetylglucosaminidase; Adolescent; Adult; Erythropoietin; Female; Glomerulonephritis, IGA; Humans; Male; Middle Aged

Absolute or functional iron deficiency decreases the effectiveness of erythropoietin in patients undergoing hemodialysis. We describe a patient who developed pica associated to a ferritin level of 800 ng/ml during recombinant human erythropoietin treatment. The symptom subsided after supplementation with iron dextran. Therefore we recommend iron supplementation during the initial phase of treatment with erythropoietin until serum ferritin levels raise above 1000 ng/ml.

Topics: Adult; Anemia, Hypochromic; Erythropoietin; Ferritins; Glomerulonephritis, IGA; Humans; Immunologic Factors; Iron; Iron Deficiencies; Male; Pica; Protoporphyrins; Recombinant Proteins; Renal Dialysis; Transferrin; Uremia