An assessment of renal failure in an SLE cohort with special reference to ethnicity, over a 25-year period

OBJECTIVES

Although the prognosis for patients with renal lupus has improved, a small number still progress to renal failure. Studies from the USA have found it difficult to distinguish whether the higher rate of renal failure in African-Americans is due to genetic or socio-economic factors. Our aim was to identify ethnic and other factors in a UK lupus cohort that contribute to renal failure.

METHODS

The University College London (UCL) Hospitals lupus cohort of 401 patients (Whites 64%, Blacks 19%), followed since 1978, has 127 patients with renal disease, of whom 21 have gone into renal failure. We determined the characteristics and possible causes of renal failure in this group. Black patients were disproportionately represented in the renal failure group (62% vs 19% for Whites).

RESULTS

Those in the renal failure group had persistently low C3 compared with the renal disease cohort. A high proportion of patients in the renal failure group were felt to be non-adherent to treatment.

CONCLUSIONS

Given that health-care for patients in the UK is free at the point of delivery, we postulate that in our cohort genetic factors rather than socio-economic status are likely to be more significant in causing renal failure. However, there may be cultural and other reasons for this, which requires further study.

Treatment of malarial acute renal failure by hemodialysis

We studied 112 patients with malarial acute renal failure (ARF) during the period 1991-1997 at Bangkok Hospital for Tropical Diseases (Mahidol University, Bangkok, Thailand). Hemodialysis was performed in 101 (90.2%) of these patients. The mean number of times the patients were hemodialyzed was 6.5 (range = 1-27). Ninety-three (83.0%) patients were oliguric and the remainder were nonoliguric. Patients who had oliguric renal failure required more hemodialyses and had more complications than the nonoliguric patients. The oliguric patients had an eight-fold higher risk of requiring six or more hemodialyses (95% confidence interval = 1.2-53.9, P = 0.0008). The overall mortality rate was 10.7% (12 of 112). Eleven of the patients who died were jaundiced and eight of them had cerebral malaria with a Glasgow Coma Score < or = 8. We conclude that hemodialysis is a useful treatment for oliguric and nonoliguric ARF from severe malaria, particularly when initiated early in the course of the illness.

Audit of infection in continuous ambulatory peritoneal dialysis

The major cause of failure of continuous ambulatory peritoneal dialysis is peritoneal or exit site infection with Staphylococcus aureus. From 1989-1992, eradication of nasal and perineal carriage, continued use of an occlusive dressing to the exit site, improved aseptic technique for dressing changes by the patient and avoidance of wetting of the dressing were used in an attempt to reduce staphylococcal infections. By comparison with the 3-year period prior to intervention, a significant increase in the life of the catheters was achieved (removed at 1 year, 13 vs. 28%, P < 0.001) with a reduction in episodes of peritonitis due to S. aureus. The study was not prospectively controlled but there did not appear to be any other factor to account for the sudden and consistent improvement observed.

Serum PAF-acetylhydrolase in severe renal or hepatic disease in man: relationship to circulating levels of PAF and effects of nephrectomy or transplantation

(1) PAF-acetylhydrolases form a major pathway for the degradation of platelet-activating factor (PAF). Here we investigate the role of the kidney and the liver in the control of PAF-acetylhydrolase levels by comparing normal subjects to patients with abnormal liver or kidney function. These patients had either severe chronic liver disease, chronic renal failure or were anephric. In a few cases PAF was also measured. (2) In those patients where PAF was measured there was no evidence that circulating PAF levels determined PAF-acetylhydrolase release. (3) In anephric patients serum PAF-acetylhydrolase levels were normal or even raised. Therefore the kidney is unlikely to be the usual major source of serum PAF-acetylhydrolase in man. (4) Liver patients with chronic cholestasis had elevated serum PAF-acetylhydrolase especially in stage III or IV primary biliary cirrhosis, as well as in a patient with secondary biliary cirrhosis and one with cholangiocarcinoma. Since normalisation of liver function following liver transplantation was accompanied by a reduction to normal or near normal PAF-acetylhydrolase levels, it is likely that the liver can play an important role in regulating levels of this enzyme in serum.

HLA-DR display by renal tubular epithelium and phenotype of infiltrate in interstitial nephritis

Renal tubular display of HLA-DR was estimated semi-quantitatively in 28 biopsies from 27 patients with various forms of tubulointerstitial nephritis (10 following use of non-steroidal anti-inflammatory drugs) using a monoclonal anti-MHC class II non-polymorphic antibody (DK-22). Normal donor kidneys and biopsies from patients with minimal-change nephrotic syndrome were examined as controls. The phenotype of infiltrating cells was also studied quantitatively, using monoclonal antibodies on frozen biopsy tissue; the number of cells infiltrating the interstitium was counted per tubular cross-section. Display of HLA-DR was seen in up to 5% of control tubular cells, but up to 100% expressed HLA-DR in tubulointerstitial nephritis biopsies. There was a correlation between the expression of HLA-DR and the severity of both tubular atrophy and tubulointerstitial fibrosis judged semi-quantitatively by optical microscopy. In controls up to 50 leucocytes per tubular cross-section were evident, but in patients with tubulointerstitial nephritis up to 1500 were observed, approximately 50% being T-lymphocytes, the majority expressing the helper phenotype except in early, active drug-induced tubulointerstitial nephritis; the remainder were mostly monocytes. There were no qualitative differences between the different causes of tubulointerstitial nephritis. Tubular DR expression correlated with the number of DR-positive cells in the interstitium, but not with total leucocytes or T-lymphocytes. HLA-DR tubular expression was greater in the early stages than late stages of NSAID-induced tubulointerstitial nephritis, but this relationship was not present in the group as whole. HLA-DR expression by renal tubular epithelial cells may play a role in localising or amplifying tubular injury in tubulointerstitial nephritis.

Tc-99m DTPA scans in renal allograft rejection and cyclosporine nephrotoxicity

Renal allograft dysfunction arising from rejection or cyclosporine (CsA) nephrotoxicity can currently only be distinguished reliably by allograft biopsy. We have assessed Technetium (Tc)-99m diethylamine pentacetic acid (DTPA) scanning in 30 CsA-treated patients with allograft dysfunction. Scintigrams were performed during 20 biopsy-proved episodes of rejection and during 14 episodes of CsA nephrotoxicity. These results were compared with the scintigrams of 15 allografts showing stable function. Quantitative indices expressing allograft perfusion (flow index) and function (uptake index) derived from the DTPA scintigrams showed no significant differences between the groups of patients with rejection, CsA nephrotoxicity, or stable or improving function. Similarly, the flow and uptake indices of individual allografts obtained during periods of stable or improving function and then during episodes of dysfunction due to rejection or CsA nephrotoxicity did not significantly change. We conclude that Tc-99m DTPA scintigrams are of limited value in the management of allograft dysfunction in patients immunosuppressed with CsA.

Renal transplantation in patients treated with haemodialysis and short term and long term continuous ambulatory peritoneal dialysis

Forty two adult patients who had been treated with continuous ambulatory peritoneal dialysis for one to 142 weeks (mean (SD) 38 (36)) received a total of 44 allografted kidneys. Twenty one had been treated with continuous ambulatory peritoneal dialysis for less than 26 weeks (mean 11 (8)) and the other 21 for longer than 26 weeks (mean 64 (35)). These two groups were compared with 55 patients who had been treated with haemodialysis and received a total of 63 grafts. In the group of patients treated with continuous ambulatory peritoneal dialysis azathioprine and low dose prednisolone were used as the immunosuppressive regimen for 20 transplantations in 18 patients, and 24 patients receiving 24 grafts were treated with cyclosporin A and low dose prednisolone. In the group of patients treated with haemodialysis 38 patients receiving 43 grafts were treated with azathioprine and low dose prednisolone, and 20 patients receiving 20 grafts were treated with cyclosporin A and low dose prednisolone. Actuarial survival of patients and grafts at two years was 95% and 72%, respectively, in the continuous ambulatory peritoneal dialysis group compared with 89% and 58%, respectively, in the haemodialysis group. No difference was found in graft survival between short term treatment with continuous ambulatory peritoneal dialysis (72% graft survival) and long term treatment (65% graft survival). In conclusion, continuous ambulatory peritoneal dialysis is suitable treatment for patients awaiting renal transplantation.

Systemic lupus erythematosus and IgA deficiency

A survey of 138 patients with systemic lupus erythematosus (SLE) (113 with nephritis) was carried out following the finding of a patient with membranous nephropathy and IgA deficiency who later developed SLE. Two hundred random hospital patients and 143 patients with idiopathic glomerulonephritis were also studied. One patient with minimal change nephrotic syndrome had IgA deficiency, but the other 342 patients had normal IgA concentrations. In the SLE group, in contrast, 4 patients had IgA deficiency and another patient prolonged IgA deficiency following phenytoin treatment. These and other published data suggest that the association of IgA deficiency is about 20 times more common in patients with SLE and nephritis than in the general population. This association may be a manifestation of defective T-cell regulation, a failure to eliminate immune complexes in the absence of IgA, or both.