Membranoproliferative glomerulonephritis in a patient with X-linked agammaglobulinemia

Immune complex and complement systems play an important role in membranoproliferative glomerulonephritis (MPGN). X-linked agammaglobulinemia (XLA) is a primary immunodeficiency characterized by severe hypogammaglobulinemia. We report the case of an XLA patient who developed MPGN during an intravenous immunoglobulin (IVIG) treatment. In this patient, the serum IgG level was maintained at more than 400 mg/dl of regular IVIG administration (2.5 g/dose/month). The patient presented with microscopic hematuria, proteinuria (U-pro/Cr: 4.0–4.2) and low serum complement levels (C3: 57.8 mg/dl) 3 years after IVIG treatment and was diagnosed histopathologically as having MPGN type III. Both hematuria and proteinuria significantly improved, and the serum complement level returned to a normal level following methylprednisolone pulse therapy. To our knowledge, this is the first case report of MPGN associated with XLA. Although it is unclear how MPGN occurred in this XLA patient, we suggest that residual humoral immunity in the patient could be associated with the development of MPGN.     

Switching from subcutaneous to intravenous erythropoietin alpha in haemodialysis patients requires a major dose increase.

BACKGROUND: A change in the licensing arrangements for the use of erythropoietin alpha in haemodialysis patients has required a switch in the route of administration from subcutaneous (SC) to intravenous (IV). Previous work suggested that the IV route was less efficacious but studies since the enforced switch have not confirmed this. METHODS: We studied haemoglobin levels and the mean weekly dose of erythropoietin alpha in 86 haemodialysis patients at monthly intervals over the 6 month period before and after a change in the route of administration of erythropoietin alpha from SC to IV. Changes in other parameters known to be associated with erythropoietin response were also monitored. RESULTS: Mean haemoglobin level fell following the switch from 11.9 g/dl+/-1.4 at baseline to 11.3 g/dl+/-1.4 at 1 month (P = 0.001) and to a trough of 11.0 g/dl+/-1.3 at 2 months (P<0.001) before partial recovery to 11.4 g/dl+/-1.2 (P = 0.007) at 6 months. Mean weekly dose of erythropoietin after 2 months was significantly higher than baseline (8791 IU+/-5314 vs 8035 IU+/-4893). The dose continued to increase and by 6 months was 10605 IU (P<0.001), 32% higher than baseline. There was a small reduction in residual renal function, which was an independent predictor of change in dose requirement. There was a small increase in parathyroid hormone levels, but no change in serum ferritin, dosing frequency, total Kt/V, serum albumin, normalised protein catabolic rate, C-reactive protein, hospitalization rate and dialyser reuse rate. CONCLUSIONS: Switching from SC to IV erythropoietin alpha caused a significant fall in haemoglobin levels in the first 2 months. This was partially reversed by 6 months at the expense of a 32% dose increase in the dose of erythropoietin alpha by 6 months. The economic impact may be considerable.     

双倍剂量ARB治疗难治性肾病综合征的临床研究

目的 难治性肾病综合征一直是世界医学的难题.本研究选择用双倍剂量血管紧张素Ⅱ受体1阻滞剂(ARB)治疗糖皮质激素和免疫抑制剂治疗失败的难治性肾病综合征,观察其临床效果. 方法 本试验为开放性自身对照临床研究.19例入选病人,符合肾病综合征的诊断标准并已排除继发性肾损害的可能.患者中病程最短为7个月,最长达24个月,均属激素联合免疫抑制剂治疗无效者.肾脏病理情况:微小病变型肾炎3例,系膜增生型肾炎3例,IgA肾病2例,膜性肾病4例,局灶节段硬化性肾小球肾炎4例.治疗方法 :11例使用缬沙坦(80mg/片),8例使用氯沙坦(50mg/片),从每日1片开始,2周后剂量增至每日2片目标剂量,自达到目标剂量起临床观察3个月.观察指标:用药前及用药后每2周检测尿常规和24小时尿蛋白、血清白蛋白(Alb)、血肌酐(Scr)、血清钾、钠、氯及谷丙转氨酶(ALT)、谷草转氨酶(AST)、直接胆红素(dBil)、间接胆红素(iBil);常规观察并记录患者水肿情况和右上肢血压;全程进行不良反应监测.按尿蛋白减少的量和降低的幅度作为疗效的评定标准:完全缓解:经治疗后尿蛋白阴转,定量检查＜0.2g/d;显著缓解:治疗后尿蛋白定量≤1g/d,或虽＞1g/d,但比治疗前减少≥50%;部分缓解:治疗后尿蛋白定量≤3g/d,或虽＞3g/d,但比治疗前减少≥50%;无效:治疗后尿蛋白无明显改善.统计数据分析用SPSS统计软件进行处理. 方法 血清蛋白水平:ARB治疗前患者血清白蛋白检测值为16.35～31.84克,平均26.96±4.72克;观察期结束时血清白蛋白值为24.71～38.82克,平均31.75±3.57克,治疗前后均值统计学差异有显著性意义(p<0.05).24尿蛋白定量:治疗前检测值为3.53～7.82克,平均4.65±1.03克;缬沙坦或氯沙坦治疗后3个月检测值为1.75～5.49克,平均2.84±1.76克,治疗前后均值统计学有显著差异(p<0.05).疗效情况:所有病例中无1例完全缓解,显著缓解5例(26.3%),部分缓解11例(57.9%);无效3例(15.8%),将前三项视为治疗有效,则有效率为84.2%. 仅1例出现短期低血压症状.结论 对于激素联合免疫抑制剂治疗无效的原发性肾病综合征,部分患者使用双倍剂量ARB治疗可减少尿蛋白排泄量,提高血清白蛋白水平.     

Contrast-induced nephrotoxicity: the effects of vasodilator therapy.

The increasingly frequent use of contrast-enhanced imaging for diagnosis or intervention in patients with peripheral vascular disease has generated concern about the incidence and avoidance of contrast-induced nephrotoxicity (CIN). In this prospective study, we sought to identify those patients at greater risk of developing CIN and to evaluate the efficacy of vasodilator therapy with dopamine in limiting this complication. Baseline serum creatinine (Cr) concentrations were obtained on admission and daily for up to 72 hr after angiography in 222 patients undergoing 232 angiographic procedures. The preangiographic treatment was varied at 2-month intervals for 1 year. All patients received an intravenous infusion of 5% dextrose and 0.45% normal saline at a rate of 75 to 125 ml/hr. During the first interval patients received 12.5 g of 25% mannitol immediately prior to their contrast load, in addition to intravenous fluids. During the next 2-month period the patients were given renal dose dopamine intravenously (3 micrograms/kg/min) commencing the evening before angiography and continued to the next morning. During the latter half of the study the treatment regimens were modified so that the use of mannitol was restricted to patients with diabetes mellitus and dopamine to patients with serum creatinine concentrations of > or = 2 mg/dl. Postangiographic elevation in Cr occurred in 2, 10.4, and 62% of studies in patients with baseline creatinine levels of < or = 1.2 mg/dl, 1.3 to 1.9 mg/dl, and > or = 2.0 mg/dl, respectively. None of the patients receiving dopamine experienced an elevation in creatinine. There was no statistical correlation between age, diabetes, or medication with calcium channel blockers and CIN.(ABSTRACT TRUNCATED AT 250 WORDS)     

Successful pregnancy in a patient with medullary cystic disease and severe renal impairment

We present a successful pregnancy in a 37-year-old women with severe renal impairment due to medullary cystic disease. She presented five years earlier with hypertension and chronic renal failure with creatinine was 2.1 mg/dl (Ccr 35 ml/min). She had had two successful pregnancies in the past, nine and seven years earlier. Diagnosis of medullary cystic disease (MCD) was made based on typical ultrasound appearance, sodium wasting and acidosis out of the proportion to the degree of renal failure. Over the next 5 years, a slow progression of chronic renal failure was observed with creatinine reaching 5.1 mg/dl (Ccr 15,4 ml/min), shortly before she became pregnant in December 2001. Her hypertension remained well-controlled and serum creatinine decreased at the beginning of the second trimester to 3.7 mg/dl with subsequent increase toward the end of the pregnancy. She required increasing doses of erythropoietin and intravenous iron supplementation to maintain hemoglobin levels. The polyhydramnios developed necessitating five procedures of amnio reduction. She was not treated by dialysis. A boy weighing 1,600 g was delivered by cesarean section in the 35th week of gestation. The mother's creatinine rose to 5.2 mg/dl (Ccr 15 ml/min) post partum and her renal function declined only slightly over the next 20 months. Our report illustrates that successful fetal and maternal outcome can be achieved even in cases of advanced renal failure preceding gestation. It appears that the type of renal disease influences the pregnancy course and outcome and thus should be considered in patient counseling and therapeutic decisions.     

SEIZURES: I

A 25-year-old man with end-stage renal disease (ESRD) secondary to obstructive uropathy suffered a generalized tonic-clonic seizure 3 hr after a routine hemodialysis treatment. The associated conditions included well-controlled mild hypertension and typical anemia of renal disease. There was no prior history of seizures, loss of consciousness, headaches, tremor, symptomatic neuropathy, or notable head trauma. His medications included nifedipine, recombinant erythropoietin, ferrous sulfate, folate, calcitriol, aluminum hydroxide, and calcium carbonate. Physical examination was remarkable only for the presence of a grade I/VI systolic ejection murmur and a patent dialysis access in the left arm. Routine predialysis laboratory data obtained two weeks previously revealed the following: Na 141, K 4.9, Cl 112, CO₂ 13 (all electrolyte values are mmol/ l), blood urea nitrogen (BUN) 68 mg/dl, calcium 6.8 mg/dl, phosphorus 4.6 mg/dl, albumin 3.5 g/dl, hematocrit 29, aluminum <1 μg/l. The electrocardiogram was within normal limits. On the day of admission the patient underwent a routine dialysis treatment for 3 hr using a new cellulose acetate dialyzer, bicarbonate-based dialysate containing potassium 1 mmol/l and calcium 2.5 mmol/l. The patient was well and asymptomatic during dialysis, and his arterial blood pressure was stable at approximately 140/90 mm Hg. Three hours after leaving the dialysis center, he began to experience facial twitching and numbness in his fingers, followed by a single 30-sec generalized tonic-clonic seizure. Upon arrival at the emergency department, he was alert and oriented, and complained only of paresthesias in his hands. Review of his medications revealed that he had failed to take the prescribed calcitriol and calcium carbonate for several weeks. Physical examination was unchanged from the previous evaluation except for the presence of Chvostek and Trousseau signs. Laboratory studies revealed the following: Na 145, K 4.6, Cl 110, CO₂ 27 (all electrolyte values are mmol/l), BUN 43 mg/dl, glucose 100 mg/dl, albumin 4.9 g/dl, total Ca 7.5 mg/dl, ionized Ca 3.0 mg/dl, magnesium 3.0 mg/dl, and phosphorus 7.0 mg/dl. EKG was normal except for a prolonged QT interval. Upon admission to the hospital, the patient was treated with intravenous calcium gluconate, followed by oral calcium carbonate and calcitriol. Within 48 hr, the patient's serum total and ionized calcium concentrations increased to 8.5 and 4.0 mg/dl, respectively. A CT scan of the head showed no abnormalities. The seizure was felt to be due to hypocalcemia, exacerbated by rapid correction of acidosis with dialysis, leading to further reduction in the ionized calcium concentration. The observed hypocalcemia was attributable to the patient's discontinuation or oral calcium and calcitriol and the absence of a high calcium dialysate, which is appropriate when combined with calcitriol and calcium supplementation, but necessary in their absence. Since discharge, the patient has experienced no further seizure activity and with consistent use of the prescribed oral calcium and calcitriol, his serum calcium has remained above 8 mg/dl, with phosphorus levels ranging from 5–6 mg/dl.     

Successful treatment of allergic purpura nephritis associated with thrombotic microangiopathy using plasma exchange: a case report

A 73-year-old man, who had an allergy to shellfish, was admitted to our hospital because of proteinuria, hematuria, purpura and extremity edema after eating oysters. Laboratory data on admission were proteinuria 2.0 g/day, hematuria 3+, serum creatinine (Cr) 1.2 mg/dl, total protein 6.3 g/dl, and albumin 3.1 g/dl. He presented a high fever with neutrophilia and rapid deterioration of renal function after admission. Based on the skin biopsy, we made a diagnosis of leukocytoclastic vasculitis with IgA deposition. Oral prednisolone (40 mg/day) following drip intravenous methylprednisolone (500 mg/day, 3 days) was administered. However, renal function and urinary findings showed no sign of improvement. In the first renal biopsy, although there were no crescentic formations, most of the glomeruli showed thrombotic microangiopathy and endocapillary proliferation with IgA deposition and electron dense deposits. Therefore, a plasma exchange was performed resulting in an improvement of the renal function. The serum Cr. level was reduced from 2.7 to 0.8 mg/dl and proteinuria from 3.7 to 0.1 g/day. In the second biopsy, the electron dense deposits with an IgA deposition had disappeared. These findings suggested that plasma exchange was effective in leading remission in a case of allergic purpura nephritis associated with thrombotic microangiopathy.     

Membranoproliferative glomerulonephritis and a rare bleeding disorder: factor X deficiency

Factor X (FX) deficiency is a rare hereditary coagulation disorder. This is the first case report on the association of FX deficiency and membranoproliferative glomerulonephritis (MPGN) type I. The patient, a 17-year-old male, presented with edema, hypertension, and microscopic hematuria, followed by a mild upper respiratory tract infection. Laboratory tests revealed: serum creatinine 1.6 mg/dl, serum albumin 2.80 g/dl, C3 16 mg/dl and proteinuria (1,800 mg/day). The renal biopsy showed MPGN type I. The coagulation profile prior to percutaneous renal biopsy revealed prolonged prothrombin time and activated partial thromboplastin time values. The patient was given fresh frozen plasma and vitamin K before the biopsy. Further evaluation showed the functional activity of FX was 7% of the norm. This case emphasizes the need for routine coagulation screening before percutaneous renal biopsy.     

A trial of two iron-dextran infusion regimens in chronic hemodialysis patients

AIM: To test the ability to elicit a hemoglobin (Hb) response in patients on chronic hemodialysis, we prospectively compared two regimens of iron dextran administration, 100 mg once weekly (QW) or 100 mg once every dialysis (QD), both given for 10 doses. PATIENTS AND METHODS: Twenty-three consecutive patients on chronic hemodialysis received iron dextran intravenously if they had absolute or functional iron deficiency. There was no difference in the Hb response between regimens. RESULTS: Both groups had a significant increase in Hb from 10.5+/-1.5 g/dl at baseline, to 11.1+/-1.7 g/dl at 1 month, 1.4+/-2.1 g/dl at 2 months and 11.6+/-1.9 g/dl at 3 months. The increment in Hb at 1 month was similar (QD 0.62+/-1.245 g/dl vs. QW 0.64+/-1.464 g/dl) between the two groups despite a large difference in the amount of iron received. Serum ferritin, transferrin saturations or epoetin dose did not change significantly. At the end of 3 months 12 patients did not need further iron therapy as judged by the serological markers of iron stores. Of these 12 patients, 3 had serum ferritins of > 1,000 ng/ml. Weekly dosing of iron was associated with more medication errors than dosing every dialysis. Baseline iron stores could not predict the responsiveness to intravenous iron therapy as judged by an increase in Hb concentration at 1 month or at 3 months. CONCLUSION: This study confirms the efficacy of 1,000 mg of intravenous iron administered over a 3-month period in patients with functional iron deficiency. It underscores the importance of careful monitoring of iron stores and highlights the need for developing better parameters of functional iron stores in hemodialysis patients.     

Randomized trial of plasma exchange or high-dosage methylprednisolone as adjunctive therapy for severe renal vasculitis

Systemic vasculitis associated with autoantibodies to neutrophil cytoplasmic antigens (ANCA) is the most frequent cause of rapidly progressive glomerulonephritis. Renal failure at presentation carries an increased risk for ESRD and death despite immunosuppressive therapy. This study investigated whether the addition of plasma exchange was more effective than intravenous methylprednisolone in the achievement of renal recovery in those who presented with a serum creatinine >500 micromol/L (5.8 mg/dl). A total of 137 patients with a new diagnosis of ANCA-associated systemic vasculitis confirmed by renal biopsy and serum creatinine >500 micromol/L (5.8 mg/dl) were randomly assigned to receive seven plasma exchanges (n = 70) or 3000 mg of intravenous methylprednisolone (n = 67). Both groups received oral cyclophosphamide and oral prednisolone. The primary end point was dialysis independence at 3 mo. Secondary end points included renal and patient survival at 1 yr and severe adverse event rates. At 3 mo, 33 (49%) of 67 after intravenous methylprednisolone compared with 48 (69%) or 70 after plasma exchange were alive and independent of dialysis (95% confidence interval for the difference 18 to 35%; P = 0.02). As compared with intravenous methylprednisolone, plasma exchange was associated with a reduction in risk for progression to ESRD of 24% (95% confidence interval 6.1 to 41%), from 43 to 19%, at 12 mo. Patient survival and severe adverse event rates at 1 yr were 51 (76%) of 67 and 32 of 67 (48%) in the intravenous methylprednisolone group and 51 (73%) of 70 and 35 of (50%) 70 in the plasma exchange group, respectively. Plasma exchange increased the rate of renal recovery in ANCA-associated systemic vasculitis that presented with renal failure when compared with intravenous methylprednisolone. Patient survival and severe adverse event rates were similar in both groups.     

Continuous intravenous sodium ferric gluconate improves efficacy in the maintenance phase of EPOrHu administration in hemodialysis patients

Although intravenous iron has proved to optimize the efficacy of EPOrHu in hemodialysis patients, hitherto no consensus exists with respect to the best regimen of intravenous iron administration. We started a prospective randomized study in 26 patients undergoing chronic hemodialysis who had adequate iron metabolism indices (serum ferritin >100 microg/l; %TSAT >20%; %HypoE <10% and CHr >26 pg) and were in the maintenance phase of EPOrHu administration (target hemoglobin obtained >10 g/dl). All patients were receiving sodium ferric gluconate (Ferrlecit) intermittently prior to the study and after a 1-month wash-out period where iron was not administered patients were randomized to receive the same previous dose of intravenous iron either in a continuous (6.25-21.3 mg in every hemodialysis session) or an intermittent regimen (62.5 mg every 1-4 weeks, not modifying the previous schedule of administration). At 16 weeks, the continuous group showed a significant increment in serum Hb (11.83 +/- 1.12 g/dl) with respect to baseline (10.96 +/- 1.31 g/dl) (p < 0.05), whereas no differences were obtained in intermittent group (baseline: 11.16 +/- 1.03 g/dl; 16 weeks: 11.14 +/- 0.90 g/dl, NS). In contrast with the intermittent group, serum ferritin increased significantly in the continuous group (16 weeks: 508 +/- 157 microg/l; baseline: 368 +/- 56 microg/l; p < 0.05), whereas %TSAT and CHr did not modified during the study in both groups. %HypoE increased significantly with respect to baseline values in the continuous group (p < 0.05) and close to significantly different in the intermittent group (p = 0.06). Our study suggests that hemodialysis patients in the maintenance phase of EPOrHu administration would obtain further benefit in terms of serum hemoglobin level with a continuous intravenous serum ferric gluconate regimen, at least in the short term.     

Comparison of intravenous ascorbic acid versus intravenous iron for functional iron deficiency in hemodialysis patients

The effect of intravenous ascorbic acid was compared with that of intravenous iron in the treatment of functional iron deficiency, as defined as serum ferritin levels over 300 ng/ml and serum iron levels below 50 microg/dl, in patients on chronic hemodialysis. Thirteen patients on chronic hemodialysis with functional iron deficiency received intravenous injections of ascorbic acid, 100 mg, three times a week, after hemodialysis. The therapy was continued until serum ferritin decreased to below 300 ng/ml (3 months at the maximum). The iron and control group were composed of patients who had serum iron levels below 50 microg/dl within 3 months after serum ferritin rose to over 300 ng/ml. Seven patients with the iron group received more than a total of 10 intravenous injections of saccharated ferric oxide (40 mg/dose) after hemodialysis, and seven patients with the control group received no iron preparation during the 3 months. In the ascorbic acid group, while hemoglobin did not change from 10.9 +/- 0.5 g/dl (mean +/- SE) during the three-month period, serum iron increased significantly from 37 +/- 4 microg/dl to 49 +/- 4 microg/dl after one month (p<0.01), and remained elevated until the end of the three-month period. Serum ferritin decreased significantly from 607 +/- 118 ng/ml to 354 +/- 30 ng/ml after 3 months (p<0.01). In the iron group, hemoglobin and serum iron increased significantly from the respective pre-treatment levels during the 2-month period, and serum ferritin rose significantly after 3 months. In the control group, hemoglobin, serum iron and ferritin levels decreased significantly from the respective pre-treatment levels during the 3 months. The recombinant erythropoietin dose remained stable for three months in the ascorbic acid, iron, and control groups, respectively. These results suggest that in hemodialysis patients with a functional iron deficiency, treatment with intravenous ascorbic acid can prevent iron overload due to treatment with intravenous iron, and provide a useful adjuvant means of maintaining hemoglobin and serum iron levels.     

Estramustine and vinblastine for patients with progressive androgen-independent adenocarcinoma of the prostate

A phase II trial was performed to assess antitumor activity and toxicity of estramustine and vinblastine in 31 consecutive patients with androgen-independent prostate cancer. All patients presented with disease progression following castrate serum testosterone levels of less than 50 ng/dl and were treated for 6 consecutive weeks with three daily 140-mg doses of oral estramustine and vinblastine at 6 mg/m(2) weekly by intravenous bolus. Prostate specific antigen (PSA) levels decreased by greater than 50% from baseline in 13 (46%; 95% confidence intervals, 27%-66%) of 28 evaluable patients. Patients who demonstrated a greater than 50% reduction in PSA had a longer delay in time to disease progression. Nonhematologic toxicity was mild, predominantly gastrointestinal. Hematologic toxicity was apparent in 13 patients with grade III granulocytopenia and in 7 patients with grade IV granulocytopenia. No patient was admitted to the hospital for neutropenic fever. Estramustine and vinblastine is a well-tolerated combination. This combination and the clinical significance of this decline in PSA warrants further investigation.     

Darbepoetin alfa effectively maintains haemoglobin concentrations at extended dose intervals relative to intravenous or subcutaneous recombinant human erythropoietin in dialysis patients.

BACKGROUND: Darbepoetin alfa is a unique molecule that stimulates erythropoiesis by the same mechanism as endogenous erythropoietin. Due to its approximately 3-fold longer half-life and greater biological activity than recombinant human erythropoietin (rHuEpo), darbepoetin alfa maintains effective haemoglobin control at extended dose intervals compared with rHuEpo. This study assessed the efficacy and safety of unit doses of darbepoetin alfa for the treatment of renal anaemia. METHODS: In this multicentre, prospective, open-label study, 1502 dialysis subjects maintained on stable rHuEpo treatment were switched to darbepoetin alfa at extended dose intervals by the same route of administration as previous rHuEpo therapy [intravenous (i.v.), n = 900 or subcutaneous (s.c.), n = 602]. Subjects receiving rHuEpo two (n = 408, 27%) or three times (n = 884, 59%) a week were switched to darbepoetin alfa once a week, and those receiving rHuEpo once a week (n = 210, 14%) were switched to darbepoetin alfa once every 2 weeks. The unit doses of darbepoetin alfa (10-150 microg) were titrated to maintain haemoglobin concentrations of 10-13 g/dl for 24 weeks. RESULTS: Haemoglobin concentrations were maintained effectively in subjects regardless of whether they received darbepoetin alfa once a week or once every 2 weeks. The overall mean change in haemoglobin from baseline to the evaluation period (weeks 21-24) was +0.10 g/dl [95% confidence interval (CI) 0.04+/- 0.17]. The mean haemoglobin concentration increased by 0.19 g/dl (95% CI 0.11+/-0.27) in subjects receiving i.v. darbepoetin alfa, and was unchanged (-0.02 g/dl; 95% CI -0.12 to 0.07) in patients treated with s.c. darbepoetin alfa. Subjects with baseline haemoglobin < 11 g/dl experienced a clinically relevant increase in mean haemoglobin concentration of 0.67 g/dl (95% CI 0.56+/-0.77) from baseline to the evaluation period. The mean weekly i.v. and s.c. darbepoetin alfa dosage requirements during the evaluation period were 19.9 microg/week (95% CI 19.02+/-20.87) and 21.6 microg/week (95% CI 20.36+/- 22.94), respectively. Darbepoetin alfa was well tolerated and the safety profile was consistent with previous trials with darbepoetin alfa in dialysis subjects. CONCLUSIONS: Treating renal anaemia with darbepoetin alfa administered at extended dose intervals is both effective and well tolerated. Moreover, administration of darbepoetin alfa by both the i.v. and s.c. route is associated with stable haemoglobin concentrations.     

Anemia as a predictor of cardiovascular events in patients with elevated serum creatinine

Patients with anemia and patients with chronic kidney disease have elevated risks for cardiovascular disease. Available studies have been too small to provide details about the relationship or to provide for extensive covariate control. In a large insurance database with linked laboratory values, records of women with serum creatinine >1.2 mg/dl and men with serum creatinine >1.4 mg/dl, identified from July 2000 through June 2003, were sought, and the insurance claims searches for hospitalizations that were associated with myocardial infarction, coronary revascularization, unstable angina, stroke, or congestive heart failure. New onset of dialysis also was sought. Multivariate Poisson regression was used to estimate rate ratios for these events at various hemoglobin (Hb) levels, with adjustment for patient characteristics and previous event history. Among 88,657 patients with high serum creatinine, the risk for hospitalization with myocardial infarction was two to five times higher in anemic (Hb <12 g/dl) patients than in people with Hb from 12.0 to 12.9 g/dl. A similar but less dramatic pattern of higher incidence of coronary revascularization was observed with lower Hb levels. Risks for hospitalization with congestive heart failure declined regularly with increasing Hb levels from a doubling of risk at Hb <10 g/dl to a 61% decrease at 15 g/dl, both relative to 12.0 to 12.9 g/dl. The risk for progression to dialysis was only slightly elevated (7 to 34%) in anemic patients. Anemia raises the risk for cardiovascular disease in patients with elevated serum creatinine.     

Uric acid: Effects on serum and urine levels in patients receiving intravenous dextrose,fat, and/or amino acid solutions

Parenteral dextrose/amino acid solutions reduce serum uric acid levels when infused into patients. To elucidate the mechanism further, 53 patients with invasive bladder cancer were selected for study. Patients received either amino acids alone (n = 13), 5% dextrose + amino acids (n = 15), 5% dextrose in water (n = 13), 25% dextrose + amino acids (n = 7), or fat 10% + amino acids (n = 5). All patients received 2500 ml intravenously for 3 days preop and 3000 ml for at least 7 days postop containing 1.4 g AA/kg/day; after Day +7 oral intake was allowed. No patient had gout. Serial serum uric acid levels and daily 24-hr urine uric acid and creatinine levels were measured. There were no significant differences among intravenous groups in: mean patient age, percentage ideal body weight, duration of operation, operative blood loss, fluid-blood replacement, or serum and urine creatinine levels. Mean serum uric acid levels decreased postoperatively in all groups. The mean change in serum uric acid levels from Day ?3 to Day +7 was significantly different between the D5/AA group (2.3 ± 0.2 mg/dl) and the AA/H₂O group (1.1 ± 0.4 mg/dl) and between the D25/AA group (2.8 ± 0.6 mg/dl) and the AA/H₂O and D5W (1.4 ± 0.3 mg/dl) group. This significant change in mean serum uric acid levels with infusion of 5 and 25% dextrose with amino acids occurred without increased uricosuria compared to the other groups of patients.     

Distal calcific uremic arteriolopathy in a hemodialysis patient responds to lowering of Ca x P product and aggressive wound care

Calcific uremic arteriolopathy (CUA; calciphylaxis), is reported in approximately 4% of patients receiving hemodialysis, and is characterized by skin lesions that may include firm plaques or subcutaneous nodules. The syndrome has been associated with the use of calcium-containing phosphate binders, high serum phosphorus levels, and elevated calcium x phosphorus (Ca x P) product. This report describes a 73-year-old white male with chronic renal failure due to diabetes mellitus and hypertension, who had been on home hemodialysis for 3 years. He developed CUA after an acute elevation in serum phosphorus (8.1 mg/dl) and Ca x P product (84.2), with painful skin lesions that rapidly progressed to become circumferentially located around the entire lower left extremity. The patient declined amputation, opting for a treatment approach that included aggressive management of phosphorus and calcium, more frequent dialysis, and rigorous wound care. All calcium-containing phosphate binders were discontinued. The patient was switched from calcitriol to paricalcitol, a less calcemic form ofvitamin D replacement therapy, from which he was slowly weaned. Dialysis dose and frequency was also increased to 4 hours, 6 times weekly. The patient was given sevelamer hydrochloride (Renagel)--a calcium-free phosphate binder--with meals at an initial dose of 6.4 g/day. After 5 months, the dose was increased to 8 g/day, with additional dietary counseling to restrict phosphorus intake. At this point, serum phosphorus decreased to 4.9 mg/dl and calcium levels had fallen to 8.5 mg/dl, compared to 9.5 - 10.4 mg/dl prior to diagnosis of CUA with an overall decline in the Ca x P product. Significant healing of the lesions was noted at 8 months following diagnosis, with near-total healing by 12 months. Our studies support that lowering of elevated serum phosphorus, calcium, and Ca x P product, together with aggressive wound care may contribute to the successful outcome of patients with CUA.     

Intravenous iron treatment of renal anemia in children on hemodialysis

Treatment of anemia in children with end-stage renal disease (ESRD) has been greatly facilitated by the introduction of recombinant human erythropoietin (rHuEPO). A major limiting factor in the treatment of renal anemia is sufficient iron supplementation. Eight children (aged 10–17 years) receiving hemodialysis were treated with intravenous iron (1 mg/kg per week) for 3 months. Hemoglobin (Hb), hematocrit (Hct), and serum ferritin levels were measured regularly. The mean Hct increased from 25% to 30%, the mean Hb increased from 7.8 g/dl to 9.2 g/dl, and the mean ferritin level from 200 to 395 mg/dl. The mean EPO dosage could be tapered from 6,500 IU to 6,150 IU. No adverse side-effects were noted. Hence, in this uncontrolled study intravenous iron was an effective treatment for iron deficiency during rHuEPO therapy in children with ESRD on hemodialysis. Received: 30 October 1997 / Revised: 17 November 1998 / Accepted: 18 November 1998     

What is the best hydration regimen to prevent contrast media-induced nephrotoxicity?

BACKGROUND: Hydration is a commonly used method to prevent the decline in GFR after contrast media (CM) application. So far, there have been no controlled, randomized trials investigating the most effective route of fluid administration. METHODS: Thirty-nine patients with normal renal function (65 +/- 9 years, serum creatinine 0.9 +/- 0.2 mg/dl, GFR = 110 +/- 31 ml/min/1.73 m2) receiving at least 80 ml of low-osmolality CM during an angiographic procedure were randomized to one of the following hydration regimens: Group 1: volume expansion with 300 ml saline during CM administration (n = 20, serum creatinine 0.8 +/- 0.1 mg/dl, GFR 119 +/- 27 ml/min/1.73 m2); Group 2: intravenous administration of at least 2,000 ml saline within 12 h before and after CM application (n = 19, serum creatinine 0.9 +/- 0.2 mg/dl, GFR 101 +/- 32 ml/min/1.73 m2). GFR was measured by CM clearance (Renalyzer) at baseline and 48 hours after CM administration. The primary end point was the mean change in the GFR after 48 hours, the secondary one was the incidence of CM-induced nephropathy (CMIN), defined as a decrease in GFR of more than 50% from the baseline GFR within 48 hours. RESULTS: Patients of group 1 showed a significantly (p < 0.05) higher decline in GFR (delta GFR 34.6 +/- 25.7 ml/min/1.73 m2) compared to patients receiving the intravenous prehydration regimen (delta GFR 18.3 +/- 25.0 ml/min/1.73 m2). The incidence of CMIN was lower in prehydrated patients (5.3%) compared to the other group (15%). CONCLUSION: In patients with normal renal function, intravenous prehydration seems to be a very effective and feasible method to prevent the decline in GFR after contrast media exposure. Volume expansion given only during the CM exposure appears not to be sufficient enough to prevent renal damage.     

Acute renal failure after exercise in a child with renal hypouricaemia

We describe a 12-year-old boy with renal hypouricaemia who presented with acute renal failure after a 6-h sports training session. Back and loin pain were noted at presentation. Although serum creatinine and blood urea nitrogen were elevated, the serum uric acid concentration was normal (2.6 mg/dl). This decreased to 0.3 mg/dl after recovery. The pyrazinamide and probenecid tests revealed that the cause of renal hypouricaemia in this patient was totally defective uric acid reabsorption. Acute renal failure after exercise is a rare but serious complication in paediatric patients with renal hypouricaemia.