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AIM: The purpose of this case report is to document an occurrence of spontaneous resolution of idiopathic retroperitoneal fibrosis and to review the investigation and management of this unusual condition. MATERIALS AND METHODS: A detailed case summary of a patient with retroperitoneal fibrosis is presented. Current citations in Index medicus from the English-speaking literature of relevance to the topic were reviewed. CONCLUSIONS: In this patient who refused open surgical intervention, bilateral stent placement allowed stabilization of renal function. CT-guided biopsy did not reveal malignancy. Serial CT imaging demonstrated gradual disappearance of the retroperitoneal mass. From the literature review, spontaneous resolution of this condition appears to be a rare phenomenon. Although often utilized, CT-guided biopsy may fail to exclude the presence of malignancy. Open surgical biopsy of the retroperitoneal mass and ureterolysis remain the standard of care for operative candidates. Establishing renal drainage and considering a trial of steroids or surveillance may be an option in carefully selected individuals.

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Hyperhomocyst(e)inemia is a probable contributor to the excess atherosclerosis of patients with chronic renal failure on dialysis. Although treatment with folate 2 mg daily is usually effective in normalizing plasma homocyst(e)ine (H(e)) in patients with normal renal function, higher doses of folate or other approaches to treatment may be necessary in renal failure. There is no agreement among dialysis units regarding the 'correct' dose of folate supplementation; routine doses range from 1 to 5 mg daily. To determine whether one of these doses is more effective, we compared H(e) in 55 hemodialysis taking 1 mg folate versus 73 patients taking 5 mg folate daily at two dialysis units. In the group as a whole, mean H(e) was 28.23 +/- 17.49, significantly higher than in a group of 290 volunteers with normal renal function 12.31 +/- 6.17 (p = 0. 0001). H(e) levels were 28.93 +/- 16.79 micromol/l on 5 mg folate and 27.31 +/- 18.49 on 1 mg; p = 0.61. There was no significant relationship between adequacy of dialysis (Kt/V) and H(e). In a small group of peritoneal dialysis patients, H(e) was significantly lower at 18.8 +/- 7.89 (p = 0.026), but further study is required in a larger sample to confirm that observation. It appears that routine doses of folate in use in dialysis units are not sufficient to reduce H(e) to levels associated with average cardiovascular risk; new approaches to treatment of hyperhomocyst(e)inemia in dialysis patients are required.

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Recombinant human erythropoietin (rHuEpo) is an effective therapy for anaemia in most patients with end-stage renal disease (ESRD). However, there remain a minority of patients with ESRD who are resistant to the effects of rHuEpo. The present study examined the role of aluminium overload and hyperparathyroidism of the biological effects of rHuEpo. Twenty-two patients aged 26-74 (mean 53 +/- SD 15.5) received rHuEpo 50-200 U/kg per week for 16.5 +/- 8.0 months (range 3-27). Haemoglobin was maintained at 11.5-13.0 g/dl by appropriate dose adjustment. Iron supplements were provided to maintain serum ferritin greater than 200 ng/ml. The mean time to rHuEpo response (Hb greater than 2 g/dl over baseline) was 6.1 +/- 2.6 weeks. Mean pretreatment serum aluminium correlated with time to Hb response (r = 0.48; P less than 0.05) and pretreatment mean corpuscular volume (r = 0.43; P less than 0.05) but not with eventual rHuEpo maintenance dose. PTH did not correlate with either Hb response or eventual maintenance rHuEpo dose. In summary, elevated serum aluminium concentrations were associated with an initial resistance to the biological effects of rHuEpo but had no effect on long-term dose requirements. In contrast, no impact of PTH on either immediate or long-term rHuEpo dose was evident.

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A retrospective study was conducted in 20 Canadian hospitals to assess peritonitis rates of CAPD patients utilizing the SCD 210 patient assist device during a 30 month study period. A total of 175 patients having a cumulative SCD experience of 1,494 patient months were included in the survey. Sixty-eight patients experienced 116 episodes of peritonitis, i.e., one episode every 12.9 patient months (pt mo). Patients that had used the SCD for their entire CAPD experience had a significantly lower peritonitis rate (1/15.2 pt mo) compared to patients who had used other CAPD systems (1/10.1 pt mo). Peritonitis rates for diabetic study patients or patients with impaired vision and/or dexterity were not significantly greater than non-diabetic or non-impaired study patients. Staphylococcus epidermidis and Staphylococcus aureus were the most frequent causative microorganisms, accounting for 27.7% and 16.0% of peritonitis episodes caused by single organisms, respectively. The proportion of peritonitis caused by skin commensals was consistent across all study patients, regardless of impairment of vision and/or dexterity. The study results demonstrate the successful application of this patient assist device in a CAPD population that consisted of a large proportion of high risk patients.

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Kappa light chain determinants were identified by immunoelectron microscopy in nodular glomerulosclerotic lesions and systemic interstitial deposits from a man who died several years after the onset of proteinuric renal failure treated by hemodialysis. He developed adrenal and hepatic failure preterminally but not overt malignant myeloma. Specific labeling was most concentrated over the inner aspect of glomerular basement membrane and the mesangium, which suggested that the protein was nonfiltrable. Tubular basement membrane labeling was densest over the outer aspect, which suggested that the protein perfused from the interstitium rather than from the tubular lumen. We identified the source of the protein as a population of plasma cells present within bone marrow and renal interstitium; these showed specific immunogold labeling for kappa light chain protein over organelles concerned with protein synthesis, secretion, and storage. This appears to be the first identification of light chain determinants in human interstitial para-amyloid deposits with the use of immunogold ultrastructural techniques in tissues prepared for electron microscopy by standard methods and stored as epoxy resin blocks.

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Patients undergoing dialysis may accumulate tissue aluminum burdens, and are at risk of developing two aluminum-associated syndromes, namely dialysis osteomalacia and encephalopathy. We address the clinical usefulness of serum aluminum levels in the diagnosis of dialysis osteomalacia. Twenty-four patients, 15 with dialysis osteomalacia and nine with clinically apparent secondary hyperparathyroidism, had serum aluminum levels measured before and after a standard infusion of a chelating agent, deferoxamine (DFO). Baseline serum aluminum levels were regarded as "high" (greater than 133 micrograms/L) if they exceeded 1 SD above the mean (74 micrograms/L) for a larger population of 152 patients undergoing routine hemodialysis. All patients had a bone biopsy for assessment of aluminum deposits by a specific histochemical stain. High serum aluminum levels had a diagnostic sensitivity of 60% in predicting those patients ultimately shown to have dialysis osteomalacia associated with histochemical evidence of aluminum accumulation in bone biopsy specimens; however, 40% of patients with histologic evidence of dialysis osteomalacia would have been missed if only serum aluminum had been used as a diagnostic test. Serum aluminum levels (+/- SEM) were 194 +/- 31 micrograms/L in patients with dialysis osteomalacia and 120 +/- 42 micrograms/L in those with secondary hyperparathyroidism (P greater than 0.05). Serum aluminum levels rose in all patients after DFO infusion to peak levels of 664 +/- 110 and 514 +/- 90 micrograms/L in patients with osteomalacia and hyperparathyroidism, respectively. However, neither the peak serum aluminum level nor its increment after DFO infusion distinguished between patients with osteomalacia and secondary hyperparathyroidism more effectively than did the baseline serum aluminum level.(ABSTRACT TRUNCATED AT 250 WORDS)

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Three patients were recently treated for thrombotic thrombocytopenic purpura (TTP). One presented with toxic shock syndrome; TTP developed but promptly responded to a regimen of antiplatelet agents, steroids and plasma exchange. In another the manifestations of TTP developed after presentation with hypertension and abdominal pain. This patient responded to a similar regimen but required extended treatment before remission could be maintained with medications alone. In the third patient the full TTP syndrome appeared after several days of plasma exchange treatment for hemolyticuremic syndrome. He did not respond. It is suggested that TTP may present in many forms initially, that microangiopathic hemolysis may be a late manifestation and that the optimal therapy is not known.

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A 54-year-old patient with fracturing dialysis osteomalacia and dementia demonstrated rapid deterioration following parathyroidectomy which was performed for sustained hypercalcemia. Reduction of the total body aluminum burden was attempted using desferrioxamine (DFO) as a chelating agent. After 6 months, DFO infusion resulted in sustained clinical remission of both neurological and skeletal symptoms, associated with an improvement in the EEG and improved mineralization of bone. A reduction in total body aluminum burden was reflected by reduced skeletal aluminum content, quantitated histochemically in iliac crest bone biopsies before and after DFO therapy. Dramatic increases in serum aluminum levels were documented in the initial weeks of DFO therapy leading to increased removal of aluminum during dialysis; in vitro studies indicated that the ultrafiltrable fraction of serum aluminum increased from 17 to more than 60% after initiating DFO treatment. However, after 6 months of therapy, serum aluminum levels remained unchanged after DFO infusion. These findings suggest that the serum aluminum response to DFO infusion might be a useful reflection of the total-body aluminum burden and also a reflection of the adequacy of a chelation program designed to reduce whole-body aluminum content.

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16 patients with advanced renal failure and histologic evidence of renal osteodystrophy were treated with dihydrotachysterol (DHT) in a dose of 0.125-0.375 mg/day. All patients had creatinine clearances of less than 22 ml/min, but none were undergoing dialysis. The rate of deterioration in renal function was determined by serial measurements of the serum creatinine and by plotting the reciprocal of the serum creatinine against time. The duration of follow-up was 17.0 +/- 8.6 months. There was no significant deterioration in renal function in 12 patients. The remaining 4 patients showed acceleration in the rate of deterioration, but the relationship to DHT therapy was unclear.

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The discovery and chemical synthesis of several biologically active derivatives of vitamin D have increased the number of compounds available for the treatment of disorders of bone and mineral metabolism. Calcitriol is the most active natural metabolite of vitamin D, but analogues like dihydrotachysterol and calcifediol also are safe and effective therapeutic agents. These vitamin D congeners have been useful in the treatment of renal osteodystrophy, hypoparathyroidism, and other disorders refractory to vitamin D therapy. Certain analogues may offer distinct advantages over vitamin D, depending on the nature of the defect. All vitamin D derivatives should be used cautiously, with frequent monitoring of serum calcium levels to prevent toxic reactions.

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Eight patients who met the clinical, immunological and renal morphologic criteria for systemic lupus erythematosus with diffuse proliferative nephritis were plasma exchanged on a monthly basis for a total of 119 months. Renal function, episodes of disease activity, hospitalizations, frequency of immunological abnormalities, and monthly quantity of steroid and azathioprine therapy were compared with their course up to one year prior to the onset of the plasma exchange program. The changes noted in these parameters indicate that chronic plasma exchange therapy is safe, may be beneficial and requires controlled prospective study to determine the role in the treatment of patients with systemic lupus erythematosus and diffuse proliferative glomerulonephritis.

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Twenty patients with nephritis due to systemic lupus erythematosus were followed up for a mean of 34 months after renal biopsy with serial determinations of total serum complement and C3 and C4 concentrations, binding of deoxyribonucleic acid (DNA), antinuclear antibody pattern and platelet count. There were 25 episodes of nonhematologic observed disease activity in 16 of the 20 patients; elevated DNA binding and thrombocytopenia correlated well with these episodes. The mean platelet count during episodes of observed disease activity was 96 +/- 42 X 10(9)/L, which was significantly different from the mean count of 248 +/- 90 X 10(9)/L during disease quiescence. The proportion of false-positive results with the immunologic tests varied from 25% to 67% and with platelet counts it was 11%. It is suggested that thrombocytopenia may be a simple and accurate index of disease activity in lupus nephritis.

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Nine of 24 patients undergoing long-term hemodialysis were found to have evidence of moderate to severe bone disease. Two had bone pain and muscle weakness and two had pseudofractures. Eight of the nine were treated with dihydrotachysterol (DHT), 0.25 to 0.375 mg/d initially, but four required doses between 0.5 and 1.0 mg/d. Ther serum alkaline phosphatase value decreased in all patients and returned to normal in six. The bone pain and muscle weakness resolved and the pseudofractures healed. Bone biopsies in six patients before and after initiation of treatment with DHT showed that the osteoid area decreased significantly from 29.6 +/- 22.8% (mean +/- standard deviation) to 11.5 +/- 7.5% (P less than 0.025) and the resorptive surface decreased in all patients. DHT, in doses of up to 1.0 mg/d, is effective in treating both the osteitis fibrosa and the osteomalacic components of bone disease in patients undergoing hemodialysis.

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Nine out of 24 patients on chronic hemodialysis were found to have biochemical, radiologic and bone biopsy evidence of moderate to severe bone disease. Two patients had bone pain and muscle weakness, 2 had pseudofractures, and one patient had a pathologic fracture of the neck of the femur. Eight patients were treated with dihydrotachysterol (D.H.T.), 0.25 to 0.37 mg/day initially. Four patients required doses between 0.5 and 1.0 mg daily. The alkaline phosphatase decreased in all patients, returning to normal in 6 patients. The symptoms of bone pain and muscle weakness resolved, and the pseudofractures healed. Repeat bone biopsies were performed in 6 patients 12 mos or more after treatment with D.H.T. The osteoid area fell from 29.6 +/- 22.8 to 11.5 +/- 7.5% (p less than 0.025). Resorptive surface decreased in all patients. D.H.T., in doses of up to 1.0 mg/day, is effective in the treatment of both the osteitis fibrosa and the osteomalacic component of bone disease in patients on hemodialysis.

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Forty-one patients on our chronic hemodialysis program were assessed for the degree of progression of bone disease over an average period of 46 months. Seven patients were using a fluoridated dialysate. Four of these seven patients developed a marked increase in osteoid as judged by bone biopsy, while in the nonfluoridated group the amount of osteoid remained within normal limits.In the absence of fluoride, although osteitis fibrosa occurred, it was reversible in 10 out of 12 cases by dihydrotachysterol treatment, and overall there was no evidence of progression of bone disease at the end of the study period.

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The adult nephrotic syndrome as met with in Nairobi is predominantly encountered in young sophisticated African women, most of whom began to use skin-lightening creams containing mercury before the symptomatic onset of their illness. The particular form of mercury involved is well known to cause the nephrotic syndrome in other circumstances-for example, when applied to the skin in the treatment of psoriasis. In these circumstances the pathogenetic mechanism is thought to be of an idiosyncratic type. The use of mercury-containing skin-lightening creams in the patients studied seemed to be particularly associated with a "minimal-change" ("light-negative") renal glomerular lesion, this lesion being present in half of the patients. The prognosis in this group of patients seems remarkably good, with 50% entering remission, 77% of these doing so spontaneously on discontinuing the use of the creams.

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