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Introduction and Aims: Therapy of primary membranous nephropathy (PMN) with progressive advanced kidney dysfunction is challenging with limited literature and no clear therapeutic strategies. This is due to the scant evidence of effectiveness and uncertainty around the risk-benefit profile of immunosuppression (ImS) when eGFR is less than 30 mL/min. We aimed to determine long-term clinical outcomes in patients with PMN and severe renal impairment treated with combined cyclophosphamide and steroids. Methods: The study is a single-center retrospective longitudinal cohort study. All patients (between 2004 and 2019) with biopsy confirmed PMN who initiated combination therapy with steroids and cyclophosphamide and had an eGFR of ≤30 mL/min/1.73 m2 at the time of initiation of therapy were included for analysis. Clinical and laboratory parameters including anti-PLA2R-Ab were monitored as per standard clinical guidance. Primary outcome was achievement of partial remission. Secondary outcomes included immunological remission, need for renal replacement therapy, and adverse effects. Results: Eighteen patients with median age of 68 (IQR 58-73) years and 5:1 M:F ratio received the combination therapy when eGFR was ≤30 mL/min/1.73 m2 (CKD-EPI). At time of ImS, median eGFR and uPCR were 23 (IQR 18-27) mL/min/1.73 m2 and 8.4 (IQR 6.9-10.7) g/g, respectively. Median follow-up was for 67 (IQR 27-80) months. 16 patients (89%) achieved partial remission and 7 (39%) achieved complete remission. eGFR increased by 7 mL/min/1.73 m2 (27%) after 1 year of starting ImS treatment and 12 mL/min/1.73 m2 at end of follow-up. Two patients (11%) developed end-stage renal disease needing renal replacement therapy. 67% achieved both immunological and clinical remission. At the end of the follow-up period, 2 (11%) patients required hospitalization secondary to infections, 4 (22%) patients developed cancer and 4 patients died (22%). Conclusion: Combination therapy with cyclophosphamide and steroids is effective in achieving partial remission and improving renal function in PMN with advanced renal dysfunction. Prospective controlled studies are required to provide further evidence to rationalize treatment and improve outcomes in such patients.
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Background: IgG4-related disease (IgG4-RD) is a systemic multi-organ inflammatory disorder which affects the kidney 20% of the time. Patients with intrinsic IgG4-related kidney disease (IgG4-RKD) often have tubulointerstitial nephritis (TIN) whereas glomerular lesions like membranous nephropathy (MN) are less common. Antibodies to thrombospondin type-1 domain-containing 7A (THSD7A) have been described in primary MN, but never in association with IgG4-RKD. Case Report: We report the first case of IgG4-MN associated with THSD7A antibodies in serum and positivity on glomerular staining, in a 57-year-old Caucasian male with IgG4-RD affecting the pancreas, liver, lacrimal glands, extraocular muscles, and kidneys. This patient presented initially with glomerular disease including significant proteinuria consistent with MN. Glomerular staining for THSD7A antigen and serum THSD7A antibody titres was positive. Treatment with corticosteroids and cyclophosphamide successfully induced remission with resolution of proteinuria, and improvement in renal function. However, despite maintenance azathioprine, the patient relapsed 39 months later. On relapse, there was minimal proteinuria but a significant rise in creatinine. Subsequent renal biopsy showed less glomerular disease and instead a TIN pattern. Subsequent treatment with Rituximab and corticosteroids successfully induced remission. Conclusion: The role of THSD7A autoantibodies in MN is emerging, and as both IgG4-MN and presence of THSD7A antibody are rare occurrences in themselves, we speculate that there may be an undiscovered association between THSD7A and IgG4-MN. Routine testing for THSD7A in IgG4-MN may help to identify the link.
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BACKGROUND: Primary membranous nephropathy is associated with variable clinical course ranging from spontaneous remission to slow progression to end stage renal failure. Achieving remission confers better renal survival in primary membranous nephropathy (PMN). Longer term outcomes such as patient survival and relapse of active disease remain poorly understood. METHODS: We performed a retrospective study of 128 consecutive adult patients diagnosed with biopsy proven PMN at a single UK centre between 1980 and 2010. These patients were followed prospectively over a median of 128 months. We assessed impact of persistent disease and relapse on Stage 5 chronic kidney disease (CKD-5) and patient survival and present longer term cumulative incidences of different end points. RESULTS: One hundred patients achieved partial remission (PartRem) and 28 patients did not achieve remission (NoRem). Nine per cent of patients achieving first remission developed CKD-5 and 75% of those with NoRem developed CKD-5 [hazard ratio (HR) 0.07, 95% confidence interval 0.03-0.19). Relapse following PartRem occurred in 31 patients (31%) during follow-up and was significantly associated with progression to CKD-5. Progression to CKD-5 was strongly associated with death (47 versus 6%, HR 23.4; P < 0.01). Cumulative incidence at 15 years following first presentation included: death, 14%; CKD-5, 28%; and relapse 40% (in patients who achieved first remission). CONCLUSIONS: Our data strongly suggest that mortality in PMN is seen in patients with disease progression to CKD-5. Achieving remission is strongly associated with improved renal survival after first presentation and following relapse. We suggest that patients who achieve remission should be followed up in longer term, and better strategies to help improve outcomes are needed in clinical practice.
