Treatment and prognosis of extracapillary glomerulonephritis

Increased incidence and improved prognosis of glomerulonephritis: a national 30-year study

Background

While there are many cross-sectional studies of glomerulonephritis (GN) incidence, changes in incidence over time, particularly in the 21st century have received less attention. Similarly, little is known about temporal changes in GN prognosis. The presence in Denmark of comprehensive registries for renal biopsy results, end-stage renal disease (ESRD), comorbidity and mortality permit these questions to be addressed.

Methods

Data for all renal biopsies in Denmark between 1985 and 2014 were extracted from the Danish Renal Biopsy Registry and Patobank registries. The date of first dialysis or transplantation was extracted from the Danish Nephrology Registry for those patients developing ESRD. Dates of death and presence of chronic comorbid conditions at date of biopsy were extracted from the National Patient Registry. The incidence of GN, adjusted to the 2013 European standard population, was calculated. ESRD incidence and mortality were calculated, both in absolute terms and after correction for age, comorbidity and presence of renal tubulointerstitial fibrosis.

Results

The incidence rose from 33.3 patients per million (ppm)/year in 1985–94 to 46.5 ppm in 2005–14. The increase could in part be related to changes in renal biopsy policy. Large increases in Anti-neutropil cytoplasmic antibody (ANCA) vasculitis (ANCAV) (3.1–7.7 ppm/year) and focal segmental glomerulosclerosis (FSGS) (1.5–5.7 ppm/year) incidence were noted. The biopsy-proven prevalence of GN in 2014 was 748 ppm of which 155 ppm were being treated with dialysis or transplantation. Adjusted ESRD incidence fell by 25% during the study period, mortality by 62% and combined ESRD/mortality by 46%. The fall in ESRD incidence was limited to minimal change GN, FSGS, membranous GN and lupus nephritis, while reductions in mortality, and the combination of ESRD and/or death, were seen for nearly all GN diagnoses.

Conclusions

This study suggests that the incidence of GN has generally increased between 1985 and 2014, but some of the increase may be related to changes in renal biopsy policy. Major increases in FSGS and ANCAV incidence have occurred. The prognosis of GN, both as regards ESRD and mortality, has improved.

Renal Oncocytoma Associated with Necrotizing Glomerulonephritis

A case of renal oncocytoma associated with focal segmental necrotizing glomerulonephritis is described. The patient showed haematuria, mild proteinuria and arterial hypertension; the diagnosis was made after right nephrectomy performed because of the presence of a renal mass. A severe re-activation of the glomerulonephritis was observed 15 months after the nephrectomy and a steroid and immunosuppressive therapy was started. Our case is the first reported in which the removal of renal oncocytoma is not followed by the disappearance of renal symptoms, as currently reported in literature, suggesting that the two diseases are not always related.

Spontaneous and protracted partial remission of microscopic polyangiitis

Microscopic polyangiitis (MPA), or microscopic polyarteritis, is an idiopathic small vessel vasculitis that frequently causes glomerular damage and renal failure and skin and lung damage in many cases. The renal lesions include focal necrotizing glomerulonephritis, extracapillary proliferative (crescentic) glomerulonephritis, and tubulointerstitial infiltration with polymorphonuclear leukocytes and lymphocytes. MPA often is associated with the presence of antineutrophil cytoplasmic autoantibody (ANCA) (myeloperoxidase positive) as a diagnostic marker. MPA commonly is regarded as a serious condition that places the survival of the kidneys and the patient at risk. Typically, there is a prodrome of some weeks to months, with rapid decline in renal function and dialysis as a potential outcome if intensive immunosuppressive treatment is not given or is delayed. We describe an otherwise typical case of MPA occurring in a 52-year-old woman presenting with multisystem disease, antimyeloperoxidase ANCA antibodies, renal impairment, and necrotizing crescentic glomerulonephritis in whom this usual sequence of events was not followed because the patient refused steadfastly to have any treatment for nearly a decade. Renal function remained stable for nearly 10 years, although there were persistent proteinuria, microscopic hematuria, and antimyeloperoxidase ANCA antibodies. A late renal-pulmonary relapse occurred, and immunosuppression was permitted only briefly. Prolonged renal and patient survival in the absence of immunosuppressive treatment has been reported rarely in this context.

Plasmapheresis in treatment of acute oligoanuria in crescentic glomerulonephritis

Plasmapheresis therapy can provide an approach in the treatment of crescentic glomerulonephritis by mechanically removing nephritogenic factors from the circulation, both antiglomerular basement membrane antibodies and circulating immune complexes as well as antineutrophil cytoplasmic antibodies (ANCAs). We present our experience with plasmapheresis treatment in patients with acute oligoanuria caused by crescentic glomerulonephritis. We used membrane plasmapheresis to treat 11 patients with crescentic glomerulonephritis with more than 80% crescent formation on biopsy and with acute onset of the disease and acute oligoanuria. The immune complex form of the disease was documented in 7, the antiglomerular basement membrane antibodies mediated (anti-GBM) form in 2, the ANCA-associated form in 1 case, and the recurrent anti-GBM form in 1 patient. Plasmapheresis was performed 2-3 times weekly using Bellco BL 500 and Gambro 2000 PF plasma filters. The total number of plasma exchanges (2,000-2,200 ml each) for each patient was 5-9. The treatment was associated with steroids and cyclophosphamide. The improvement of renal function with the start of diuresis and significant decrease of creatinine from the range of 786-1,301 microM at the start of the treatment was noted in 5 of the 11 patients. The duration of remission without hemodialysis was 6-12 months. Treatment with plasmapheresis in cases with recurrent anuria was without benefit. We can conclude that plasmapheresis can delay end-stage renal failure in cases with acute onset of crescentic glomerulonephritis.

Prognostic factors in Wegener's granulomatosis

We analysed data from 64 patients with Wegener's granulomatosis to determine predictor variables of outcome. The mean period of observation after the diagnosis had been established was 3.2 (range 0.1-11.2) years. At the time of diagnosis, 15 (23%) patients had only local symptoms. The disease was generalized to multiple organs in 49 (77%) patients. Renal biopsies were obtained in 33 patients; 13 (39%) had extracapillary glomerulonephritis, which was the most common renal lesion. All but three patients received immunosuppressive therapy. At time of follow-up, 17 (27%) patients were in complete, and 26 (40%) in partial remission. We employed a Kaplan Meier analysis to identify predictor variables of outcome. Renal involvement, initial creatinine concentration, serum albumin or total protein concentration, leukocyte count and erythrocyturia proved to be predictor variables. These variables may be of value in guiding the intensity of treatment in patients with Wegener's granulomatosis.

Plasma exchange in focal necrotizing glomerulonephritis without anti-GBM antibodies

To determine whether plasma exchange was of additional benefit in patients treated with oral immunosuppressive drugs for focal necrotizing glomerulonephritis (without anti-GBM antibodies), we performed a randomized controlled trial with stratification for renal function on entry. Forty-eight cases were analyzed, 25 in the treatment group (plasma exchange, prednisolone, cyclophosphamide and azathioprine) and 23 in the control group (drug therapy only). There was no difference in outcome in patients presenting with serum creatinine less than 500 mumol/liter (N = 17), or greater than 500 mumol/liter but not on dialysis (N = 12), all but one of whom had improved by four weeks. However, patients who were initially dialysis-dependent (N = 19) were more likely to have recovered renal function (P = 0.041) if treated with plasma exchange as well as drugs (10 of 11) rather than with drugs alone (3 of 8). Long-term follow-up showed that improvement in renal function was generally maintained. The results of this trial confirm that focal necrotizing glomerulonephritis related to systemic vasculitis responds well to immunosuppressive drugs when treatment is started early, and suggest that plasma exchange is of additional benefit in dialysis-dependent cases.

Reversal of progressive necrotizing vasculitis with intravenous pulse cyclophosphamide and methylprednisolone

We describe a patient with polyarteritis nodosa who, despite therapy with daily doses of oral prednisone and cyclophosphamide, developed acute renal failure. Renal histopathologic examination demonstrated crescentic glomerulonephritis. Treatment with intravenous pulse cyclophosphamide and methylprednisolone resulted in clinical improvement and significant recovery of renal function.

The treatment of glomerulonephritis in children

The results of treatment of glomerulonephritis (GN) in childhood with oral corticosteroids, immunosuppressive drugs, anticoagulants and the newer regimens of pulsed, high-dose intravenous methylprednisolone and plasma exchange are reviewed and compared with the natural history of the untreated condition. Poststreptococcal GN and the nephritis of Schönlein-Henoch purpura need no specific treatment unless extensive glomerular crescents are present. The progression of mesangiocapillary GN can probably be slowed or even reversed with long-term, alternate-day steroid therapy. As in adults, recovery of renal function in GN due to antibody to glomerular basement membrane can be achieved in some patients using plasma exchange, but only those in whom some renal function is still present when treatment is started. In rapidly progressive (extracapillary) GN with crescents, "traditional" therapy with oral steroids, immunosuppressive drugs and anticoagulants reduces renal mortality from 85%-90% to about 50%, while pulsed methylprednisolone and plasma exchange improve the outcome further, mortality falling to about 25%. It is recommended that children with crescentic GN and deteriorating function be treated initially with pulsed methylprednisolone, followed by plasma exchange in those who fail to respond or who deteriorate following temporary response to pulse therapy. Treatment must be given early in the course of the illness if good results are to be obtained.

The existence of a protracted course in crescentic glomerulonephritis

We describe a spectrum of clinical and morphologic features which may occur in idiopathic crescentic glomerulonephritis. Of note are patients who pursue a more indolent course to renal failure in contrast to typical rapidly progressive glomerulonephritis (RPGN). Patients following this protracted course have an insidious presentation with hematuria and renal insufficiency, and at the time of renal biopsy (usually after many months of clinical illness) show less extensive involvement with crescents, which are often in both cellular and fibrous stages. This form of crescentic glomerulonephritis is further distinguished from RPGN by frequent hypertension and the nephrotic syndrome, the absence of oligo-anuria and progression to renal failure over many months or even years.