The effect of on-line high-flux hemofiltration versus low-flux hemodialysis on mortality in chronic kidney failure: a small randomized controlled trial.

BACKGROUND: Given the paucity of prospective randomized controlled trials assessing comparative performances of different dialysis techniques, we compared on-line high-flux hemofiltration (HF) with ultrapure low-flux hemodialysis (HD), assessing survival and morbidity in patients with end-stage renal disease (ESRD). STUDY DESIGN: An investigator-driven, prospective, multicenter, 3-year-follow-up, centrally randomized study with no blinding and based on the intention-to-treat principle. SETTING & PARTICIPANTS: Prevalent patients with ESRD (age, 16 to 80 years; vintage > 6 months) receiving renal replacement therapy at 20 Italian dialysis centers. INTERVENTIONS: Patients were centrally randomly assigned to HD (n = 32) or HF (n = 32). OUTCOMES & MEASUREMENTS: All-cause mortality, hospitalization rate for any cause, prevalence of dialysis hypotension, standard biochemical indexes, and nutritional status. Analyses were performed using the multivariate analysis of variance and Cox proportional hazard method. RESULTS: There was significant improvement in survival with HF compared with HD (78%, HF versus 57%, HD) at 3 years of follow-up after allowing for the effects of age (P = 0.05). End-of-treatment Kt/V was significantly higher with HD (1.42 +/- 0.06 versus 1.07 +/- 0.06 with HF), whereas beta(2)-microglobulin levels remained constant in HD patients (33.90 +/- 2.94 mg/dL at baseline and 36.90 +/- 5.06 mg/dL at 3 years), but decreased significantly in HF patients (30.02 +/- 3.54 mg/dL at baseline versus 23.9 +/- 1.77 mg/dL; P < 0.05). The number of hospitalization events for each patient was not significantly different (2.36 +/- 0.41 versus 1.94 +/- 0.33 events), whereas length of stay proved to be significantly shorter in HF patients compared with HD patients (P < 0.001). End-of-treatment body mass index decreased in HD patients, but increased in HF patients. Throughout the study period, the difference in trends of intradialytic acute hypotension was statistically significant, with a clear decrease in HF (P = 0.03). LIMITATIONS: This is a small preliminary intervention study with a high dropout rate and problematic generalizability. CONCLUSION: On-line HF may improve survival independent of Kt/V in patients with ESRD, with a significant decrease in plasma beta(2)-microglobulin levels and increased body mass index. A larger study is required to confirm these results.

The ultrastructural basis of renal pathology in monoclonal gammopathies.

The kidney is frequently involved in the course of monoclonal gammopathies (MG). Renal involvement presents different clinical-morphological patterns, which can occur either at the onset or in a late phase of the hematological disease, as well as after chemotherapy. The reasons for the organ tropism of monoclonal immunoglobulins (Igs) are still unknown. Currently, it is well known that some primary structure alterations in monoclonal Igs and/or in their segments correlate to nephrotoxicity. On the other hand, it is impossible to predict the pathogenicity and the clinical manifestations induced by a specific monoclonal Ig based on its specific conformational modifications. Pathogenicity and organ tropism are probably complex phenomena, which involve specific protein factors, patient factors, target organ characteristics and monoclonal plasmacellular mass entities. However, aminoacidic sequence analysis of nephrotoxic Igs and some recent in vitro studies have allowed two different monoclonal light chain (LC) types to be distinguished. Glomerulopathic LCs (G-LCs) in the mesangium recognize their target structure and induce two distinct mesangiopathies, monoclonal Ig deposition disease (MIDD) and AL-amyloidosis (AL). Tubulopathic LCs (T-LCs) act on the proximal or on the distal tubule and cause, respectively, Fanconi syndrome (FS) and cast nephropathy. Pathogenic monoclonal Igs have the propensity to deposit in different renal parenchymal structures in extracellular sites, because of the transformation of soluble precursors in insoluble products. Evidence suggests that somatic mutations can destabilize the normal LCs globular soluble structure and this could be the major driving force for precipitation. Based on these features, MG can be classified as conformational and depositional diseases. Electronmicroscopy (EM) analysis of renal biopsies in MG patients with glomerular diseases distinguishes two morphological aspects. MIDD and a recently identified entity named proliferative glomerulonephritis (GN) with monoclonal IgG deposits are both characterized by non-organized granular electrondense deposits. AL, immunotactoid (IT) glomerulopathy and monoclonal cryoglobulinemia are, instead, characterized by organized deposits such as fibrils or microtubules. Tubular diseases in MG patients produce two different histological patterns. In FS, monoclonal Igs form crystals in the renal interstitium able to induce a local intense flogosis, while in cast nephropathy monoclonal Igs precipitate with Tamm-Horsfall protein (THP) in the proximal tubular lumen and induce tubular obstruction. The different morphological aspects are unrelated to specific clinical manifestations, while renal biopsy can diagnose different entities that can respond to different therapeutical schedules. This reveals the importance of the renal biopsy in the clinical management of the renal pathology in plasma cells dyscrasias, mainly when supported by the most advanced techniques of immunoelectronmicroscopy and polymerase chain reaction (PCR)-mediated analysis. Further elucidation of the molecular events involved in the pathogenesis of the different forms of renal damage is needed to design new and more effective therapeutical strategies. In particular, urinary proteomics seem to be promising in this setting.

Efficacy and tolerability of manidipine in the treatment of hypertension in patients with non-diabetic chronic kidney disease without glomerular disease. Prospective, randomized, double-blind study of parallel groups in comparison with enalapril.

BACKGROUND: Calcium channel blockers (CCBs) are effective blood pressure lowering agents, giving rise to a prevalent dilation of the afferent arteriole. Manidipine, a long-lasting dihydropyridine CCB, demonstrates its action not only on the afferent arteriole, but also on the efferent one. This suggests theoretically a renoprotective effect in patients with chronic kidney diseases (CKD). METHODS: This was a multicenter, prospective, randomized, double-blind, parallel group study, to evaluate the efficacy and tolerability of manidipine (M; 10-20 mg/day), in comparison with enalapril (E; 10-20 mg/day) in the treatment of hypertension in 136 patients with CKD secondary to primary renoparenchymal disease. Changes in blood pressure values from baseline were considered as the primary outcome of the study. Proteinuria changes and the rate of renal function decline were also evaluated. RESULTS: During a 48-week follow-up, mean SBP decreased from 155+/-11.7 to 138.7+/-13.9 mmHg in M and from 157.3 +/-11.8 to 134.2+/-13.9 mmHg in E; mean DBP decreased from 100.3+/-4.2 to 86.1+/-6.5 mmHg in M and from 100.3+/-4.2 to 84.7+/-6.3 mmHg in E. Proteinuria remained unchanged in M (from 1.6+/-1.59 to 1.62+/-1.79 g/24h), and decreased significantly in E (from 1.37+/-1.45 g/24h to 1+/-1.55 g/24h). No significant difference was observed in the rate of renal function decline in the two groups. CONCLUSIONS: Manidipine was safe and effective, obtaining a significant reduction in SBP and DBP from baseline. Although patients treated with enalapril showed a better antiproteinuric response, the two treatments were equally effective in reducing the rate of CRF progression in patients without glomerular disease.

Adult nondiarrhea hemolytic uremic syndrome associated with Shiga toxin Escherichia coli O157:H7 bacteremia and urinary tract infection.

About 15% of children with Shiga toxin (Stx) producing Escherichia coli (STEC) primarily of serotype O157:H7, gastrointestinal infection, and watery or bloody diarrhea, may develop hemolytic uremic syndrome (D+ HUS). Usually D+ HUS is not complicated by bacteremia and patients recover spontaneously without antibiotic treatment. We report here an adult case of a STEC O157:H7 urinary tract infection complicated by bacteremia and HUS that was not preceded by diarrhea (D- HUS). Cases of D- HUS need to be carefully examined for foci other than the gastrointestinal tract, and patients with E coli bacteremia should receive early antibiotic treatment as would any patient with sepsis.