Intensive haemodialysis using PMMA dialyser does not increase renal response rate in multiple myeloma patients with acute kidney injury.

BACKGROUND: Intensive haemodialysis (IHD) in addition to bortezomib-based chemotherapy might be efficient to rapidly decrease serum immunoglobulin-free light chains removal in patients with multiple myeloma (MM) and to improve renal prognosis and survival. METHODS: The aim of this retrospective multi-centre study was to compare the efficacy (renal recovery rate) of IHD and of standard haemodialysis (SHD) in patients with MM and dialysis-dependent acute kidney injury (AKI), concomitantly treated with bortezomib-based chemotherapy. RESULTS: We selected 41 patients with MM and dialysis-dependent AKI, most likely due to myeloma cast nephropathy (MCN), and who were treated in eight French hospitals between January 2007 and June 2011. Patients were classified in two groups according to dialysis regimen: IHD [n = 21, with a mean of 11.3 dialysis sessions all with poly(methyl methacrylate) (PMMA) membranes for 13.2 days] and SHD (n = 20 patients, mostly three times per week, 31% with PMMA membrane). The main outcome was dialysis-independence at 3 months. At 3 months, 15 patients could stop dialysis: 8 (38.1%) in the IHD and 7 (35%) in the SHD group (P = 1). Moreover, 14 (56%) of the 25 patients who did show haematological response and only one of the 16 patients who did not were dialysis-independent (P = 0.002) at 3 months. CONCLUSIONS: The results of this retrospective study did not show any clear renal benefit of IHD in patients with MM and MCN compared with SHD. Conversely, they underline the importance of the haematological response to chemotherapy for the renal response and patient prognosis.

Tubulointerstitial nephritis and Fanconi syndrome in primary biliary cirrhosis.

Primary biliary cirrhosis is a chronic cholestatic liver disease of unknown cause that predominantly affects middle-aged women. Distal tubular acidosis is the main renal complication of primary biliary cirrhosis. Tubulointerstitial nephritis and Fanconi syndrome have been reported more rarely. We report on 2 patients with primary biliary cirrhosis who presented with tubulointerstitial nephritis and Fanconi syndrome and review similar cases published previously. Serum from 1 patient exerted an inhibitory effect on pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase, 2 mitochondrial enzymes that are the main targets of antimitochondrial antibodies in primary biliary cirrhosis. Antimitochondrial antibodies may have a role in the genesis of tubulointerstitial nephritis and Fanconi syndrome, 2 typical renal features of mitochondrial cytopathies. Tubulointerstitial nephritis and Fanconi syndrome have to be added to the spectrum of renal diseases associated with primary biliary cirrhosis.