Effects of triple therapy in IgA nephritis: a follow-up study 5 years later

This study is a 5-year post trial assessment of patients with IgA nephritis who entered a 3-year prospective controlled trial of cyclophosphamide, dipyridamole (D) and low-dose warfarin (W). Patients entered the trial from 1979 to 1981 and the trial ended in 1984 with those in the treatment group having more stable renal function and less proteinuria compared to the control group. Present reassessment of the patients in 1989 showed no difference in the renal function between those in the treatment group (n = 27) and the control group (n = 21). 6 patients in the treatment group and 7 in the control group were in ESRF. At the conclusion of the trial in 1984, among the 27 patients in the original treatment group, 13 patients elected to continue with D + W while the other 14 patients chose to cease therapy and therefore served as the new control group. 5 years later, renal function in the new treatment group (n = 13) was significantly stable compared to the new control group (n = 14), (serum creatinine 1.4 +/- 0.7 versus 4.4 +/- 3.2 mg/dl, p less than 0.01). Furthermore, all the 6 patients with ESRF in the original treatment group of 27 patients were from the new control group (n = 14) where treatment with D + W had been ceased. None of the patients still on D + W are in ESRF.

Pharmacokinetics and nephrotoxicity of cyclosporine

Cyclosporine (CsA) is a potent immunosuppressive agent which has dramatically improved graft and patient survivals in clinical solid organ transplantation. However, CsA nephrotoxicity (NTX) is the most frequent and serious side effect of CsA therapy and occurs in a significant proportion of patients. The clinical presentation of NTX is that of reduced creatinine clearance, elevation of serum creatinine and a disproportionate rise in blood urea. The clinical picture occurs as three syndromes, namely acute, subacute and chronic CsA NTX. Regardless of the clinical syndrome, the pathoaetiology of NTX is related to decline in renal blood flow and increase in renal vascular resistance probably due to CsA induced changes in renal haemodynamics. Unfortunately, the dose that yields an optimal therapeutic index, namely maximal efficacy with minimal toxicity has yet to be defined. Optimal dosing is confounded by not only inter and intraindividual variabilities in drug absorption, distribution and metabolism, but also by the lack of a clear relationship between drug efficacy and trough CsA level monitoring. This paper describes the pharmacokinetics and nephrotoxicity of CsA and evaluates various strategies to overcome this toxicity.

Pattern of proteinuria in IgA nephritis by SDS-PAGE: clinical significance

Of sixty patients with IgA nephritis, none had CRF at first examination, 13 developed CRF with creatinine above 1.6 mg/dl within 6 years. Among these patients who had analysis of proteinuria by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), 31 patients had middle molecular weight (MMW) proteinuria alone (pattern 1), 10 had MMW and Low MW (LMW) or tubular proteinuria (pattern 2), 10 had high MW (HMW) and MMW proteinuria (Pattern 3) and 9 had HMW, MMW and LMW proteinuria (Pattern 4). At the end of a follow up period of 6 years (1983-1989) patients with mixed proteinuria had a higher incidence of chronic renal failure (CRF), 11/29 (38%) compared to those with pattern 1 proteinuria, 2/31 (6%) (chi 2 = 8.7, p less than 0.005). Based on the glomerular selectivity index (GSI), 19 patients had nonselective proteinuria but they did not have a higher incidence of CRF. By the selectivity index (SI), 18 patients had nonselective proteinuria and they showed a significantly higher incidence of CRF. Compared to the 41 patients who did not have LMW proteinuria, 19 patients with LMW proteinuria had more severe proteinuria. After a follow-up period of 6 years, patients with LMW proteinuria had a higher incidence of CRF (10% versus 47%, p less than 0.001). The presence of LMW proteinuria indicates a less favourable outcome and the pattern of proteinuria as assessed by the SDS-PAGE appears to be a better prognostic index in IgA nephritis than the SI and the GSI.

Maintenance haemodialysis in Singapore

The chronic haemodialysis programme of the Singapore General Hospital started in 1968 as a hospital-based fully nurse-assisted programme. This has since expanded to include Self Dialysis and Home Dialysis programmes. Data of 425 patients who entered the dialysis programmes was analysed retrospectively. The major cause of end stage renal failure was chronic glomerulonephritis (52%). Almost half of the patients in the haemodialysis programme were patients on self-dialysis (49%). There were 157 withdrawals and 116 deaths. Survival has improved tremendously with the use of treated water for dialysis from 1981. The 5 year survival in an earlier group of patients dialysed with untreated water was 48% compared with 81% in a late group dialysed with treated water (p less than 0.001). The pattern of complications has also changed with a lower incidence of dialysis osteomalacia, hypertension, hepatitis and eradication of dialysis dementia.

Acute renal failure prognostic indices in hospital inpatients referred for haemodialysis

Forty-eight patients with acute renal failure (ARF) who were referred to the Department of Renal Medicine, Singapore General Hospital for acute dialysis between August 1985 and August 1989 were studied retrospectively to identify risk factors associated with ARF that serve as prognostic indicators. There was no difference in the mean age of survivors and non-survivors (49.5 +/- 17.5 years vs 53.5 +/- 18 years, p greater than 0.05). The overall mortality rate was 52%. ARF as a result of surgical complication had a higher mortality rate in comparison to ARF from medical complications (66% vs 50%, p greater than 0.05). Septicaemia was the most common cause of ARF requiring dialysis. Hepatobiliary sepsis was the most frequent cause of septicaemia. Pre-dialysis serum urea and creatinine levels, and the number of dialysis treatments did not affect the outcome. Poor prognostic indicators included oliguria or anuria, fluid overload and coma. Patients tended to have a worse outcome if they had more than three risk factors taken from the following list:-decreased renal perfusion, assisted ventilation, coma, gastrointestinal dysfunction, recent surgery, sepsis, congestive heart failure, hepatobiliary dysfunction, malignancy, diabetes mellitus, chronic renal insufficiency and poor nutritional status. Early referral of patients with septicaemia due in particular to hepatobiliary infection may improve the prognosis.

Influence of Extended Practice on Programming Time, Movement Time, and Transfer in Simple Target-Striking Responses

Two experiments describe the effects of extended practice on the development of motor control programs for simple target-striking responses. In Experiment 1,400 right-hand trials of simple one-target and two-target striking tasks were performed. In Experiment 2,600 practice trials were given. Overall reaction time (RT) was faster for the one-target condition in both experiments, supporting a response complexity effect. Movement time (MT) for both conditions improved linearly with practice, suggesting that development of the motor control programs was still occurring. Subjects then transferred to a three-target condition for 50 trials, performing the transfer task with the right hand in Experiment 1, and with right and left hands in Experiment 2. Transfer to the three-target conditions produced execution errors in the form of failure to contact the second target and repetitive tapping on the third target. These results suggest that extensive practice may serve to firmly entrench a response sequence, making it difficult to implement a similar, but unique, motor control program. An interpretation in terms of automaticity and enhanced priming of behavioral and neural pathways is offered to account for these results.

Acute glomerulonephritis--changing patterns in Singapore children

This study compared the pattern of acute glomerulonephritis (AGN), a disease known to be influenced by socioeconomic and environmental factors, in children 12 years and under, for the years 1971 and 1985. All children admitted to the four major paediatric departments with haematuria and at least two of the following (oedema, hypertension or oliguria) had an initial diagnosis of AGN. A sample population from one unit from 1980 to 1984 showed that over 70% of these children had evidence of a post-streptococcal aetiology. In 1971, 411 children were admitted with AGN, as compared with only 58 in 1985. The age-sex-race standardized rates for 1971 and 1985 were 0.632 and 0.023/1,000 children 12 years and under, respectively (P less than 0.001). The mean age of presentation was lower in 1971. Over this period, Singapore saw a threefold rise in the gross national product, accompanied by rapid urbanization. On analysis of the housing pattern, only 31% of the children lived in high-rise apartments in 1971, in contrast with 86% in 1985 (P less than 0.001). The majority of non-apartment dwellers had homes in rural districts. From an epidemiological perspective, factors which could have led to the highly significant decline in prevalence of AGN in Singapore children included improvement in the socioeconomic status and health care system, and urbanization of the country.

The effects of nutrients on the survival of Escherichia coli in lake water

Escherichia coli was shown to survive without decline in viable counts for at least 12 d in filtered-autoclaved lake water. In unfiltered lake water there was a rapid decline in the viable count of E. coli. The addition of synthetic sewage to filtered-autoclaved lake water led to an increase in the viable count of E. coli at 15 degrees C and 37 degrees C and to an increase in the survival time of the E. coli in unfiltered water. The addition of phosphate and carbon sources (glucose, glycerol, succinate, acetate and lactose) did not significantly increase the survival time of E. coli in unfiltered water over the controls. The addition of ammonium sulphate and some amino acids (as nitrogen sources) to the unfiltered lake water did lead to an increase in the survival times for E. coli and this increase was proportional to the concentration of the added nitrogen source.

Pattern of glomerulonephritis in Singapore children--a renal biopsy perspective

This study was aimed at determining the pattern of glomerulonephritis (GN) in Singapore children from a histopathological perspective. Fifty-seven consecutive children, aged between 10 weeks to 16 years, who underwent a renal biopsy at the Departments of Paediatrics, National University of Singapore and Singapore General Hospital over an 8 year period were studied. The main indications for biopsy were nephrotic syndrome (67%), recurrent gross haematuria (16%), nephritic syndrome (7%), and renal failure (10%). Primary GN occurred in 81%, while secondary GN was seen in 19%, the most common being lupus nephritis. Of the primary GN, minor abnormalities was the most common (22%), followed by focal global sclerosis (20%), focal segmental glomerulosclerosis (17%), diffuse mesangial proliferative GN (11%), focal mesangial proliferative GN (9%), membranous GN (7%), diffuse endocapillary GN (4%), diffuse sclerosing GN (4%), diffuse mesangial sclerosis (4%), and diffuse crescentic GN (2%). Immunofluorescent examination was performed in 50 children. IgA nephropathy was diagnosed in 17% of the patients with primary GN. Of the children with primary nephrotic syndrome due to minimal change disease or focal global sclerosis, about half had IgM mesangial deposits. Of 47 patients who were followed up, 9 developed chronic renal failure, of which 7 reached end-stage disease (4 have died, while 3 are on chronic dialysis). Three other patients died of other complications. The histopathological findings influenced the therapeutic decision in 49% of our patients. In summary, the pattern of GN in our cohort of patients tended to reflect more severe glomerular lesions, mainly due to our criteria of selection for renal biopsy.

Protein selectivity: a prognostic index in IgA nephritis

Among 98 patients with IgA nephritis who had protein selectivity studies performed, 54% had nonselective proteinuria and the remaining 46% had selective proteinuria. Patients with nonselective proteinuria had a higher incidence of glomerulosclerosis. At the end of a 4-year follow-up period, patients with nonselective proteinuria had lower creatinine clearance, higher incidence of hypertension and chronic renal failure when compared to patients with selective proteinuria. Six out of eleven patients (55%) in the study who had the nephrotic syndrome had selective proteinuria. Among these 6 patients, 1 had spontaneous remission and 5 responded to steroid or cyclophosphamide therapy. The remaining 5 patients with nonselective proteinuria did not respond to therapy. In the patients who had selectivity studies repeated, the data showed that the selectivity index (SI) can fluctuate depending on the clinical course of the patients. SI can therefore be used to monitor the progress of patients on long-term follow-up. Protein selectivity appears to be a useful prognostic index in IgA nephritis. For patients with the nephrotic syndrome it may serve as a guide to therapy.

Anti-vascular endothelial cell antibodies in patients with IgA nephropathy: frequency and clinical significance

This study examined the frequency of anti-vascular endothelial cell (VEC) antibodies (Ab) in 72 patients with IgA nephropathy (IgAN), and their possible relationship to clinical and histological parameters of the disease. An enzyme immunoassay was developed to measure the binding of sera to endothelial cells grown to a confluent monolayer. Thirty-two percent of IgAN patients had serum anti-VEC activity as compared to 4% of controls (P = 0.004) and 9% of patients with other primary glomerulonephritis (P = 0.017). This was shown to be due to anti-HLA class I Abs in 6 of the 23 IgAN patients, and in the 1 control positive for anti-VEC activity. Hence 17 IgAN patients had anti-VEC Abs, predominantly of the IgA subclass. Stimulation of the endothelial cells with interferon-gamma and interleukin 1 did not increase the binding of these Abs. There was no correlation with circulating immune complex (IC) levels, and removal of ICs in positive sera by ultracentrifugation did not decrease anti-VEC binding. Significant correlations were found between anti-VEC Abs and proteinuria greater than 1 g/day (P = 0.044), as well as IgA anti-VEC Abs and C3 or IgA deposition in renal arterioles (P = 0.048). These IgA Abs may be an important marker of pathogenetic activity in IgAN.

Hypertension in IgA nephropathy

Among 151 patients with IgA nephritis, 18/151 (12%) had hypertension at presentation and 50/151 (33%) were hypertensive after an interval of 65 +/- 40 (Mean +/- SD) months. Hypertensive patients (n = 50) had a higher incidence of glomerulosclerosis, medial hypertrophy of blood vessels, tubular atrophy, poorly selective proteinuria and extension of immunodeposits to peripheral capillary walls compared to normotensive patients (n = 101). Chronic renal failure occurred more commonly among hypertensives compared to normotensive patients (42%) versus 14%. However, the time taken for patients to reach renal impairment or end stage renal failure was not significantly different. The cumulative renal survival for the hypertensive group was 78% after 8 years compared to 91% in the normotensive group (p less than 0.05). In the second part of the study, patients who were hypertensive at presentation (n = 18) were compared with those who developed hypertension on follow up (n = 32). Apart from a shorter duration of follow up for patients with hypertension and a higher incidence of glomerulosclerosis, there were no significant differences in their clinical presentation, laboratory indices or other histological parameters. The incidence of chronic renal failure and the time taken to reach end stage renal failure were not different. Uncontrolled hypertension was an important cause for rapid deterioration to end stage renal failure within 3 years, compared to 8 years when hypertension was controlled.

Controlled therapeutic trial of IgA nephritis with follow-up renal biopsies

Forty-eight patients with IgA nephritis entered a 3 year controlled prospective trial using a combination regimen of cyclophosphamide for 6 months and dipyridamole and low dose warfarin for 36 months. Those in the treatment group (n = 27) had stable renal function and a significant decrease in proteinuria (p less than 0.01) but in the controlled group (n = 21) there was a significant fall in creatinine clearance (p less than 0.01) and rise in serum creatinine (p less than 0.02) with no change in proteinuria. The data suggested that the above treatment resulted in a significant reduction of proteinuria and more stable renal function. Eleven patients in the treatment group and 10 patients in the controlled group had repeat renal biopsies after the trial. Eight parameters were used in the evaluation of the renal biopsies: mesangial hypercellularity, crescents, tuft adhesion, segmental sclerosis, global sclerosis, tubular atrophy, interstitial fibrosis and vascular sclerosis. Each lesion was graded from 0 to 3 and a total scoring system used for evaluation of histological severity. In the treatment group there was no significant histological deterioration but in the controlled group there was progressive histological deterioration. Mean total histological score was 3.7 +/- 2.6 before the trial and 6.5 +/- 3.1 after the trial (p less than 0.05). This histological progression appeared to run parallel with the clinical course.

Immunology of renal transplantation in Singapore

Renal transplantation is the best form of renal replacement therapy for patients suffering from endstage renal failure. While correcting the metabolic consequences of uremia, it is the only form of replacement therapy which permits full rehabilitation of the patient. However, the successful engraftment of a renal allograft is frequently limited by immunologically mediated graft loss which can be as high as 50% in the first year in cadaveric transplants. Since the beginning of the history of transplantation, various methods of modifying allograft rejection, both pretransplantation and posttransplantation have been studied. In this paper, we report the pretransplantation immunological factors that appear to modulate graft survival in renal transplantation in Singapore.

An unusual case of peritonitis

Though peritonitis is a common complication in Continuous Ambulatory Peritoneal Dialysis (CAPD), tuberculous peritonitis has been reported in only twelve CAPD patients in the world English literature to date. Successful outcome in those reported cases involved antituberculous therapy and in the majority, catheter removal and conversion to maintenance haemodialysis. We report in this article our first case of tuberculous peritonitis in a CAPD patient. The diagnosis was made at laparotomy in our patient and she improved with antituberculous therapy. CAPD was continued without interruption. In haemodialysis patients, mortality from tuberculosis is reported to be high due to atypical presentation and delay in diagnosis. To avoid this delay, we recommend that the clinician have high index of suspicion for tuberculous peritonitis in CAPD patients with sterile peritonitis. Early diagnosis carries a good prognosis, and CAPD need not necessarily be discontinued in these patients.

Detection of bovine serum albumin in the circulating IgA immune complexes of patients with IgA nephropathy

Alimentary antigenic challenge has been postulated to have a role in the genesis of IgA circulating immune complexes (CIC), resulting in mesangial IgA disease. In this study, we examined the relationship between bovine serum albumin (BSA) and IgA CIC in patients with IgA nephropathy. Of the 47 patients studied, elevated IgA CIC levels were found in 32% by the F(ab')2 anti-C3 and Raji cell enzyme immunoassays (EIA). Elevated IgA anti-BSA antibody levels were found in 9 patients, and there was a positive correlation between these levels and IgA CIC as measured in the Raji cell EIA (R = 0.60, P less than 0.001). In 4 patients with elevation of both IgA CIC and IgA anti-BSA antibody levels, solubilization experiments were done to demonstrate the presence of BSA antigen in the IgA CIC. Using the Raji cell EIA, the IgA CIC levels decreased significantly after preincubating the sera with serial concentrations of excess BSA. No corresponding effect was seen with human serum albumin used as control. Hence, BSA may be the antigenic stimulus in the formation of IgA CIC in selected patients with IgA nephropathy. The pathogenic capacity of these IgA-BSA CIC remains to be determined.

Effects of triple therapy on the progression of mesangial proliferative glomerulonephritis

Fifty-two pairs of patients with idiopathic diffuse mesangial proliferative glomerulonephritis entered a controlled 3-year prospective trial of a combination regimen of cyclophosphamide, dipyridamole and warfarin. In the treatment group proteinuria decreased significantly (p less than 0.01) and renal function remained stable, but in the control group there was no change in proteinuria and creatinine clearance (Ccr) decreased significantly (p less than 0.01). The time patients with renal impairment in the control group and those in the treatment group took to reach end stage renal failure was significantly different (6.1 years versus 8.9 years, p less than 0.02). Among the patients with IgA nephritis, those in the treatment group (n = 27) had stable renal function and a significant decrease in proteinuria (p less than 0.01) but in the control group (n = 21) there was a significant fall in Ccr (p less than 0.01) and rise in serum creatinine (p less than 0.02) with no change in proteinuria. Among 23 pairs of patients in the study who were matched for renal function and degree of glomerulosclerosis, those in the treatment group had stable renal function and decrease in proteinuria (p less than 0.01) whereas those in the control group had decreased Ccr (p less than 0.01) but no change in proteinuria.

Glomerulonephritis in Singapore: an overview

The pattern of glomerulonephritis (GN) consisting of 1057 renal biopsies is presented. Primary GN accounted for 91% and secondary GN 9% of which the commonest is lupus nephritis. Asymptomatic haematuria and proteinuria was the commonest mode of presentation (41%), gross haematuria 9%, nephrotic syndrome 29% while 5.5% presented with renal impairment and 4.3% with hypertension. Mesangial proliferative GN is the commonest histopathological lesion forming 66% of all primary GN. Minimal Lesion, Focal Global Sclerosis and Focal Segmental Glomerulosclerosis accounted for 7% each. Membranous GN was uncommon (3%) while Mesangiocapillary GN, Diffuse Endocapillary GN and Crescentic GN were even rarer. If the presenting feature was asymptomatic haematuria and proteinuria the likely diagnosis was IgA nephritis, and, if nephrotic syndrome it was likely to be Idiopathic Mesangial Proliferative GN but with negative staining on immunofluorescence. The course and prognosis of the various forms of GN are next discussed. Nephrotic syndrome with Minimal Lesion has an excellent prognosis while Crescenteric GN usually carries a grim prognosis. Finally, factors affecting the progression of IgA nephritis, the commonest form of GN occurring in Singapore are examined. Patients who developed renal failure ran two different courses; one was a slowly progressive course over an average of 7.7 years before reaching end stage renal failure (ESRF), while the other was a more rapid decline to ESRF within an average of 3.3 years where severe uncontrolled hypertension seemed to be the major adverse factor. 9% had renal impairment at the end of a follow up of 50 + 1/2 - 34 months while 5% progressed to ESRF. The cumulative renal survival was 91% after 6 years with no further loss up to 14 years. Unfavourable long term prognostic indices were proteinuria of more than 2 gms, hypertension, crescents on renal biopsy, severe segmental sclerosis and medial hypertrophy of blood vessels.