Renal involvement in systemic amyloidosis: an Italian collaborative study on survival and renal outcome.

BACKGROUND: Few data are available from large population-based studies on survival and renal outcome of patients with renal involvement and different types of systemic amyloidosis. METHODS: Two hundred and ninety of over 373 patients affected from systemic amyloidosis with renal involvement diagnosed in Italy between January 1995 and December 2000 were followed from diagnosis to death or until the last available clinical control. Eighty-three patients were excluded from analysis either because the amyloid type remained undetermined or they were lost at follow-up. Clinical and laboratory information was collected according to the different types of amyloidosis using a specific form which included renal function with 24 h proteinuria at diagnosis and at the end of follow-up, the type and the date of onset of dialysis and the kind of treatment they underwent. RESULTS: The median time of follow-up was 24 months in primary (AL) amyloidosis (range: 1-88 months), 16 months in AL with associated multiple myeloma (MM + AL: range 1-76 months), 30 months in reactive (AA) amyloidosis (range: 1-99 months) and 52 months in patients with familial forms (AF: range 14-82 months). Patients with AL showed a significantly shorter survival than AA. Despite no significant differences of renal outcome or survival on dialysis being observed between the two groups, a lower renal survival with a higher number of patients who progressed to end-stage renal disease (ESRD) was observed in patients with AA. Overall survival was markedly improved in patients with AL who underwent a specific therapy (conventional chemotherapy or autologous stem cell transplantation (ASCT)) even in the absence of a positive kidney response. Multivariate analysis showed cardiac involvement and specific therapy to significantly influence survival in AL whereas age, serum creatinine (sCr) and heart involvement significantly affected survival in AA. In both groups, sCr and heart involvement were the most relevant predictors for renal outcome, together with urinary protein excretion, in patients with AA. CONCLUSIONS: Our results show a worse survival in AL due to the higher prevalence of heart involvement in this group and emphasize that a specific therapy significantly prolongs survival and slows the progression of renal disease in patients with AL. We suggest that a late nephrological referral is likely the cause of the higher sCr found at presentation in patients with AA and probably accounts for the lower renal survival observed in the short term in these patients. At the time being, renal transplantation and ASCT are still rare therapeutic options for renal patients affected from systemic amyloidosis.

GIT (Glucose Infusion Test): polycentric evaluation of a new test for vascular access recirculation.

Introduction. Vascular access recirculation (AR), which is often unacknowledged, remains an important cause of inadequate dialytic dose. The glucose infusion test (GIT) is a new method for detecting and quantifying AR. This paper reports on a polycentric evaluation of the new test and a comparison with the classical Urea-test (UT). Methods. GIT protocol comprises withdrawal from the arterial port (sample A), injection into the venous drip chamber of 1 g glucose in 4 seconds, withdrawal from the arterial port (sample B) continuously from 13 to 17 seconds. Glucose is determined on A and B by a reflectance photometer. If B = A then there is no recirculation. If B exceeds A by at least 20 mg/dl there is recirculation. AR quantification: AR% = (B-A) / 20. GIT was performed on 623 patients from eleven dialysis centers to screen the patients for AR. Subsequently, GIT and Urea-test (UT) were compared in 189 paired tests. The reproducibility of GIT and UT was studied in 28 paired tests performed in sequence. Results. The screening test by GIT was positive in 68 cases (11 %). The majority of positivities was found in central venous catheters (CVC, 27/50 cases, 54 %), whereas only 7 % of artero-venous fistulas (AVF) were positive. In the CVC group, Tesio catheters were more frequently positive compared to Dual Lumen Catheters (64 % vs. 29 %). The comparison GIT - UT showed that results matched in 162 tests (79 negative and 83 positive both by GIT and UT), showing that on the grounds of UT, GIT has high sensitivity and specificity. In 27 tests GIT was positive, but UT negative. This disagreement is due to the different minimal limit of detection, 1 % for GIT and 5% for UT. The reproducibility was greater with GIT than with UT with a lower D% (respectively -0.6 +/- 2.5 and -0.4 +/- 6.1 %, p<0.001) and a lower coefficient of variation (17 vs 33 %). Conclusions. The screening of 623 patients by GIT confirmed that AR in AVF is normally absent, whereas an un-expectedly high frequency of moderate AR in CVC was found. The GIT-UT comparison showed that the new test is simple and immediate, and gives results with higher accuracy, sensitivity and reproducibility than UT.

Lp(a) levels: effects of progressive chronic renal failure and dietary manipulation.

Patients with chronic renal failure (CRF) have an increased risk of cardiovascular disease (CVD). Elevated lipoprotein(a) (LP(a)) levels have been shown to be an important risk factor for CVD. This study examined Lp(a) changes during the progression of renal disease in patients following different dietary regimens. Fifty-seven patients with CRF of different etiology and degree (mean age 58 +/- 10 yrs) were divided into four groups according to their serum creatinine (sCr) levels. The first group had sCr 1.5-3; the second 3-6; the third > 6, all on a conventional low-protein diet (CLPD), and the fourth had sCr > 6 on a supplemented vegetarian diet (SVD). Lp(a), apoproteins AI, B, E, CII, CIII, CII/CIII, Apo A/Apo B ratios and the lipid pattern (total cholesterol (TC) and its fractions LDL, HDL, HDL3 and triglycerides) were investigated. Patients with diabetes, proteinuria > 1.5 g/24 h, hepatic disease or taking contraceptives or lipid lowering drugs were excluded. Results were compared with a reference group (N = 12) with sCcr < 1. Lp(a) concentrations increased with the progression of renal failure, and a significant correlation was observed with sCr. Despite the elevated sCr levels, patients on the SVD had an almost normal Lp(a) concentration. Only 15% of the reference group had Lp(a) levels > 30 mg/dl, compared to 33%, 50% and 78% of the 1st, 2nd and 3rd groups and 38% of the 4th group. No relationship was found between Lp(a), lipids or apoproteins. Our results indicate that renal function influences Lp(a) levels and suggest a SVD helps to lower them. This might be ascribed to some antioxidant factors in the SVD.

[Percutaneous nephrolithotomy of renal staghorn calculi. Experience with monotherapy treatment]. / Nefrolitotomia percutanea della calcolosi a stampo renale. Esperienza di trattamento monoterapia.

Seventy patients with renal staghorn calculi were treated with percutaneous nephrolithotripsy monotherapy. Nine patients (13%) required more than one nephrostomy to remove the stone: an overall success rate was obtained in 67% of the cases, with 27% of residual asymptomatic fragments. Open surgery was necessary in 4 patients for complications. No nephrectomies were carried out. Comparing complete and partial, better results as expected, were obtained in partial staghorn calculi. Evaluating results stratified per number of treatments, we obtained a stone-free rate of 35% with only one treatment, and 61% with two percutaneous sessions, at the discharge from the hospital. To date, initial percutaneous debulking of the stone followed by ESWL treatment on residual stones, seems to be the most suitable approach to branched calculi. However, in selected cases, PCNL treatment alone, can obtain removal of the stone in a significant percentage of cases, with minimal morbility, and, what's more, at the discharge from the hospital, without any ancillary procedure or rehospitalization.

Chronic total renal artery occlusion: a diagnostic challenge.

Chronic renal artery occlusion must be suspected whenever a moderate hypertensive patient over 50 years of age presents increase of blood pressure refractory to treatment, sometimes causing heart failure or stroke. This suspicion is reinforced by the presence of renal insufficiency and of anatomical and/or functional lateralization of renal damage at intravenous pyelography.