Antiproteinuric effect of captopril in a patient with lupus nephritis and intractable nephrotic syndrome

The renin-angiotensin system in lupus: physiology, genes and practice, in animals and humans

Although multiple studies suggest a potential role for angiotensin II in inflammation, most were performed either in vitro or in animals with non-immune-complex-mediated diseases. Extrapolation of these findings to humans, particularly patients with lupus, which involves multiple immunoregulatory pathways, is unclear. In autoimmune-prone MRL/lpr mice, angiotensin-converting-enzyme (ACE) inhibition improved survival although to a lesser degree than cyclophosphamide and diminished the glomerular histopathologic damage, proteinuria, lymphoid hyperplasia, dermatitis, and hypergammaglobulinemia, with a reduction in TGF-beta1 and beta 2 expression in the kidneys and renal chemokine mRNA expression. Spleen levels of IL-4 and IL-10 were also reduced. Uncontrolled studies in patients with treatment-refractory lupus nephritis showed a significant reduction in proteinuria with ACE-inhibitors and Angiotensin receptor blockers treatment. The ‘masking’ effect of ACE-inhibitors should be taken into consideration, as an exacerbation of lupus nephritis may be missed when estimated by the magnitude of proteinuria, which is decreased by these treatments. No single ACE genotype was consistently associated with subsets of SLE patients. In retrospective analyses, ACE-inhibitor use predicted a favourable outcome in 94 cases of pauci-immune vasculitis. The attenuating effect of angiotensin II inhibitors on the progression of chronic renal disease is well recognized. The data on the role of this intervention in lupus is limited.

Captopril effect on prostaglandin E2, thromboxane B2 and proteinuria in lupus nephritis patients

OBJECTIVE

High urinary Prostaglandin E2 (PGE2) and thromboxane B2 (TxB2) levels have been reported in lupus nephritis (LN). Captopril diminishes proteinuria and improves glomerular filtration rate (GFR), and may have effect on immune function. We evaluate captopril effect on urinary PGE2, and TxB2.

METHODS

Eighteen LN patients were randomly assigned to two groups. Group 1 received only prednisone plus cyclophosphamide. Group 2 received also captopril. Serum creatinine, GFR, RPF, urinary proteins, PGE2 and TxB2, were assessed.

RESULTS

There were no differences between the initial and final assessments in Group 1. Group 2 showed a significant decrement in proteinuria (p=0.003) and serum creatinine (p=0.01) at the end of the study. PGE2 decreased significantly when compared with the initial value (p=0.02).

CONCLUSION

Captopril plus usual treatment, improved serum creatinine and decreased proteinuria in parallel with prostaglandin E2 reduction. This effect is not related to changes in GFR or RPF. Captopril may have an immunomodulatory effect on local inflammatory processes in lupus nephritis.

An ACE inhibitor reduces Th2 cytokines and TGF-beta1 and TGF-beta2 isoforms in murine lupus nephritis

BACKGROUND

Angiotensin-converting enzyme (ACE) inhibitors, such as captopril, are used to control hypertension. In patients and animals with primary nephropathies, these agents improve renal function more than that would be expected from their control of hypertension. Here, we examine the effects of treatment with captopril on lupus nephritis and discuss the potential mechanism(s) by which this agent exerts its renoprotective effects.

METHODS

Lupus-prone, NZB/NZW F1 and MRL-lpr/lpr, mice were treated with captopril or with a control antihypertensive agent, verapamil. Mice were monitored for nephritis, and their sera and tissues analyzed for cytokine and transforming growth factor-beta (TGF-beta) expression.

RESULTS

Captopril treatment delayed the onset of proteinuria when administered to prenephritic mice, whereas verapamil did not. Captopril treatment also retarded disease progression when given to lupus mice that had early disease, and even reversed severe proteinuria in at least some older animals with advanced disease. It reduced chronic renal lesions, but had no effect on autoantibody production. The improvement in renal disease correlated with reduced TGF-beta expression, particularly of the TGF-beta1 and TGF-beta2 isoforms, in the kidneys. Interestingly, in vivo or in vitro exposure to captopril reduced splenic levels of type 2 cytokines, interleukin (IL)-4 and IL-10, suggesting a possible role of the immune system in captopril-mediated disease modulation.

CONCLUSION

Since type 2 cytokines are known to promote lupus glomerulosclerosis, decreased IL-4 and IL-10 production in captopril-treated mice may be related to this agent's renoprotective effects. We argue here that ACE inhibitors not only act as selective TGF-beta inhibitors, but also as selective immunomodulators, to improve lupus nephritis.

Captopril and aspirin in treatment of renal microangiopathy in primary antiphospholipid syndrome

Treatment of antiphospholipid syndrome (APS) is controversial. We report a case of renal microangiopathy in a 40-year-old woman with APS. The nephropathy was isolated without signs of disseminated thrombotic microangiopathy or progressive systemic sclerosis. Similarities with sclerodermatous kidney and an increase in plasma renin activity led us to initiate treatment with aspirin and captopril, with excellent control of the renal syndrome. We believe this therapeutic regimen may be an effective means of treating the renal microangiopathy of APS.

Refractory nephrotic syndrome in lupus nephritis: favorable response to indomethacin therapy

The effects of indomethacin on urinary protein excretion, levels of serum albumin and renal function were studied prospectively in six patients with systemic lupus erythematosus (SLE) and refractory nephrotic syndrome due to lupus nephritis. Two had membranoproliferative glomerulonephritis, two had diffuse proliferative glomerulonephritis, and one each had mesangioproliferative and membranous glomerulonephritis. All experienced a considerable reduction in urinary protein excretion and an increase in serum albumin. Indomethacin was discontinued in two patients because of side effects, and proteinuria recurred to pretreatment levels. The decrease of proteinuria continued during long-term treatment in three patients. Indomethacin did not cause a permanent decline in renal function. Our results suggest that therapy with indomethacin may be beneficial for the treatment of refractory nephrotic syndrome in selected SLE patients. However, because of potential side effects the administration of indomethacin should be monitored closely.