The investigative burden of membranous nephropathy in the UK

BACKGROUND: Membranous nephropathy (MN) represents two distinct disease entities. Primary MN is now recognized as an autoimmune condition associated with the anti-PLA(2)R antibody and secondary MN occurs in tandem with malignancy, infection, drug therapy and other autoimmune conditions. Prior to the development of accessible enzyme-linked immunosorbent assays, the diagnosis of MN was one of exclusion. We studied whether the introduction of serum anti-PLA(2)R antibody testing leads to a reduction in the frequency of investigations in MN patients. METHODS: Patients from three UK centres with a diagnosis of MN between 2009 and 2014 were identified. We compared patients who had a positive anti-PLA(2)R test within 6 months of biopsy with those who had no test or a negative test. Records were reviewed for investigations that took place 6 months prior to and 6 months following the biopsy date to see if these were normal or identified a secondary cause of MN. RESULTS: In total, 184 patients were included: 80 had no test, 66 had a negative anti-PLA(2)R test and 38 had a positive test within 6 months of diagnosis. In 2012, 46.5% of patients had an anti-PLA(2)R test, increasing to 93.3% in 2014. From 2012 to 2014 the number of screening tests dropped from 10.03 to 4.29 and the costs from £497.92 to £132.94. CONCLUSIONS: Since its introduction, a progressively higher proportion of patients diagnosed with MN had an anti-PLA(2)R test. This has led to a reduction in the number of screening tests and in the cost of investigations carried out. The anti-PLA(2)R test has the potential to reduce this burden as its use becomes more widespread.