High-dose calcitriol therapy and progression of cardiac vascular calcifications.

BACKGROUND: Dialysis patients show a very high prevalence of cardiovascular complications, affected as they are with abnormal and accelerated vascular calcifications and, eventually, calcium and phosphorous metabolism disorders. Multislice computed tomography (MSCT) provides a reproducible, high-resolution imaging of calcium contained in cardiac arteries, measured by Agatston score. The aim of the present study was to evaluate the influence of high-dose and low-dose calcitriol therapy on the progression of cardiac vascular calcifications in dialyzed patients. METHODS: We enrolled 36 dialyzed patients in a prospective study, including an interventional period of 12 months and a follow-up period of 12 months. Eighteen protocol patients received intravenous pulses of high-doses calcitriol at the end of dialytic treatment and sevelamer hydrochloride therapy. Control patients received low-dose calcitriol and sevelamer hydrochloride as well. Two MSCT scans were performed: 1 at the start of the study and 1 at the end of follow-up, and Agatston score was calculated at both examinations. RESULTS: At first examination, protocol patients showed almost the same level of cardiac vascular calcification as control patients. At the second MSCT, statistically significantly higher values of Agatston score were recorded for all patients. Indeed, patients who showed higher baseline values developed worse calcifications as recorded at the end of follow-up, both in the protocol and control group. CONCLUSIONS: Our data show that baseline level is strongly predictive of vascular calcification progression, and, moreover, there is no association between calcitriol administered doses and the progression of cardiac vascular calcification.

Infectious complications in renal transplant recipients.

Renal transplantation has become a well-established therapeutic option for end-stage renal disease, but infectious diseases remain a significant cause of morbidity and mortality. Although a wide variety of pathogens may cause infection, viral ones must be regarded as the single most important class of infections. Progress has been made both in the prevention and the early recognition treatment of infections that are closely linked to rejection. Immunosuppressive therapy is central to the pathogenesis of both. Because of the particular characteristics of transplant recipients, it is desirable to establish a close collaboration between nephrologists, surgeons, and infectious disease specialists for the management of these patients. In this article, we describe the different kinds of infectious disease that may affect patients with kidney transplant and the fundamental principles of clinical management, particularly our experience in Polyoma virus (BK) infection.

Living donor transplant: wider selection criteria.

The availability of cadaveric donor organs is insufficient for actual needs. The organ demand increases by 20% per year. Living donor transplant (LDT) may be a valid therapeutical alternative provided one uses proper criteria. LDT provides many advantages, like improved patient and organ survival, short waiting time, and the possibility to carefully plan the procedure. Potential risks include perioperative mortality and renal dysfunction in the kidney donor. At present, kidney LDTs in Italy represent 8% of the total, with an organ survival rate of 97% after 1 year (vs 93% for cadaveric transplants) and donors mortality rate of almost null. Most LDTs are performed from kinsmen. Presently, law no. 458, 26 June 1967, is in force in Italy for kidney LDT and law no. 453, 16 December 1999, for liver LDT. The foundations of LDT are, of course, the recipient's condition, the donor's motivation, and the altruism of the donation. It is desirable that in the future an increasing number of LDT be performed, supported by a careful, widespread health education regarding organ donation from living subjects and by the possibility to obtain insurance for the donor, which has been considered but never provided by actual laws.

Polyoma virus BK and renal dysfunction in a transplanted population.

INTRODUCTION: Reactivation of polyoma virus BK (BKV) is increasingly recognized as a cause of severe renal-allograft dysfunction. The aim of the present study was to evaluate prevalence of BKV infection and activity in a population of kidney (KT) and liver (LT) transplant patients and search for a possible correlation with renal dysfunction. METHODS: We studied 118 patients for BKV viruria and, when present, for BKV viremia. We also assessed HCV status. RESULTS: Among 16 patients with BKV viruria (5 LT and 11 KT), eight showed BKV viremia (one LT and seven KT). Among BKV viruria-positive patients, three LT recipients were HCV-positive. All LT BKV viruria-positive patients showed normal renal function with a mean serum creatinine (sCr) blood level of 0.9 mg% and a mean blood urea nitrogen (BUN) value of about 36 mg%. The mean transplant age was 2.5 years. In contrast, KT BKV viruria-positive patients showed impaired renal function which was slightly worse in patients who also displayed BKV viremia, namely, a mean sCr blood level 1.7 mg% and a mean BUN value about 80 mg%. The mean transplant age was 7 years. CONCLUSION: Based on these findings, it seems that BKV viruria in renal allograft recipients may be associated with viremia and related to nephropathy that may lead to allograft rejection. The study will be completed with a 2-year follow-up of positive patients to assess the possible relationship between BKV active infection and eventual decrease of renal function and loss of transplanted organ.

[Long-term clinical experience in post-dilution HFR]. / Diciotto mesi di esperienza clinica su HFR on-line in post-diluizione.

PURPOSE: Hemodiafiltration reinfusion (HFR) is characterized by the use of regenerated ultrafiltrate as replacement fluid. We devised a new technique, post-dilution HFR, aimed at increasing the purification efficiency, treatment tolerability and at reducing inflammatory state. METHODS: We performed post-dilution HFR in six uremic patients during 18 months. Dialytic efficacy, filter blood rest and cytokine behavior were evaluated. RESULTS: Neither pyrogenic reactions nor other adverse phenomena were recorded. The tolerance to the treatment was excellent. We observed a high rate of urea extraction and optimal Kt/V values, a high extraction of beta2 microglobulin (beta2-m) and a reduction in blood rest; in addition, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) significantly decreased. CONCLUSIONS. The inversion of the standard HFR configuration allowed us to improve the removal of both urea and beta2-m, and the blood rest, with an optimal tolerability. Moreover, the reduction in cytokine levels could attenuate the uremic microinflammatory state.