Tailored dialysis start may allow persistence of residual renal function after graft failure: a case report.

BACKGROUND: Restarting dialysis after kidney transplantation is a critical step with psychological and clinical implications. Maintenance of residual renal function a known factor affecting survival in chronic kidney disease, has so far not been investigated after a kidney transplantation. THE CASE: A 54-year-old woman who started dialysis in 1974 (first graft, 1975-1999) received a second "marginal" kidney graft in February 2001 (donor age, 65 years). Her chronic therapy was tacrolimus and steroids. She had a clinical history as follows: nadir creatinine level of 1.5 mg/dL, moderate-severe hypertension, progressive graft dysfunction, nonresponsiveness to addition of mycophenolate, tapering FK levels, and a rescue switch from tacrolimus to rapamycin. From October to December 2003, the creatinine level increased from 2-2.8 to 7 mg/dL. Biopsy specimen showed malignant and "benign" nephrosclerosis, posttransplantation glomerulopathy, and tacrolimus toxicity. Chronic dialysis was started (GFR <3 mL/min). Rapamycin was discontinued. Dialysis was tailored to reach an equivalent renal clearance of >15 mL/min (2 sessions/wk). Blood pressure control improved, nephrotoxic drugs were avoided, and fluid loss was minimized (maximum 500 mL/hr). By this policy, renal function progressively increased to GFR >10 mL/min in May 2004, allowing a once or twice weekly dialysis schedule, with good clinical balance, and obvious advantages for the quality of life. CONCLUSION: This long-term patient, who restarted dialysis with severely reduced renal function, regained sufficient renal function to allow once weekly dialysis. Thus, careful tailoring of dialysis sessions at the restart of dialysis may allow preservation of residual kidney function, at least in individuals for whom a subsequent graft is unlikely.

Limited value of zinc protoporphyrin as a marker of iron status in chronic hemodialysis patients.

BACKGROUND: In an attempt to find new parameters able to evaluate the actual iron availability by bone marrow cells, zinc protoporphyrin (ZnPP), a metabolic intermediate generated in the red blood cell by the incorporation of zinc instead of iron, has been proposed. ZnPP is a good marker of iron-deficiency anemia in non-uremic people, as red blood cell ZnPP concentration rises specifically (except for lead intoxication) in this condition. Existing data on ZnPP as a marker of iron deficiency in uremic patients comes mainly from cross sectional studies on chronic hemodialysis and has produced conflicting results. SUBJECTS AND METHODS: Therefore, we prospectively studied 42 HID patients, 28-88 years old, 13-346 months of dialysis age, beginning from a period of maximal iron deficiency, due to the lack of parenteral iron compounds (T0) up to the end of more than one year of follow-up with continuous parenteral iron supplementation (T4). ZnPP, hemoglobin, transferrin saturation and ferritin were serially determined before and after six weeks (T1), four months (T2), seven months (T3) and 14 months (T4) of parenteral iron supplementation at a maintenance dose of 0.5-1 mg/kg/week. RESULTS: In comparison with baseline values (95+/-37 micromol/mol heme) there were no significant changes in ZnPP levels at T1 and T2 despite a continuous increase in both transferrin saturation and ferritin values, while ZnPP significantly decreased at T4 (63+/-37 micromol/mol heme, p<0.001). There was no correlation between ZnPP and both transferrin saturation and ferritin at any time during the study, the same was true for ZnPP and zinc and lead serum concentration, fibrinogen and reactive C protein levels at T1 and T4, respectively. At T4, only 2/10 patients who still showed ZnPP levels >80 micromol/mol heme had absolute or functional iron deficiency, when the percentage of hypochromic red cells were measured. CONCLUSION: We conclude that ZnPP untimely parallels a change in iron balance in only a proportion of uremic people, in as much as confounding factors, such as chronic inflammation and uremia in itself may obscure its relationship with iron status. Therefore, ZnPP cannot be assumed to be a first-line diagnostic marker of iron balance in uremic patients.

Dramatic worsening of vascular calcifications after kidney transplantation in spite of early parathyroidectomy.

Vascular calcification is a common feature in chronic dialysis patients, but their clinical significance is debated and the role of kidney transplantation (TP) in the natural history of their development has received scanty attention. We will describe a case of dramatic worsening of vascular calcifications during TP in a young patient in spite of early and successful parathyroidectomy (PTX), and will discuss other causes which might be putatively linked to vascular damage during the time of TP. A 37-year-old man on regular dialytic treatment (RDT) for 11 years, received his first cadaveric transplantation in January 1993. He underwent PTX 6 months after TP because of the lack of decreasing in parathyroid hormone values despite normal graft function. Although PTX was effective, a dramatic worsening was evident in large as well as in medium and small-sized arteries during the following three years of TP. In February 1997, few months after starting dialysis again because of the recurrence of his primary membranoproliferative glomerulonephritis (MPGN), the patient experienced myocardial infarction followed by aorto-coronary bypass (right coronary artery and anterior descending coronary artery) and leg "claudicatio". Though a role for parathyroid hormone in vascular disease has been commonly accepted, the case here reported clearly shows that blunting parathyroid gland activity may be unable to avoid the worsening of a process of vascular disease during the time of TP. Many other factors--linked to the time of TP--may be involved in vascular diseases, such as nephrotic syndrome, dyslipidemia, hypertension and drugs. In the case of our patient, a clear cut risk factor for his progressive atherosclerosis can be designated hyperlipidema and other disturbancies secondary to a nephrotic syndrome due to relapse of MPGN, together with persistent hypertension. This is the first case report in the English literature which clearly demonstrates that TP may add fuel to the fire of vascular disease also in young people and even in the absence of parathyroid hyperactivity, perhaps on the basis of a favorable genetic background. Furthermore, the history of our patient demonstrates that vascular calcifcation heralds major cardiovascular diseases.

[Vascular calcification after kidney transplantation. Preliminary results]. / Le calcificazioni vascolari dopo trapianto di rene. Risultati preliminari.

BACKGROUND: Vascular calcifications (VC) are a common feature in chronic dialysis patients, but their clinical significance is debated, and the role of kidney transplantation (TRP) in the natural history of their development has received only scanty attention. METHODS: In our study we reviewed skeletal surveys as well as clinical and biochemical records of 13 patients who started again chronic dialysis at our Centre after failure of their kidney grafts. Changes of VC (during TRP) were scored as: 1 = no substantial progression (4 patients), 2 = moderate worsening (4 patients), 3 = severe worsening (5 patients = 38.4%). RESULTS: The most interesting association with the clinical/biochemical parameters seems to be between the score 3 subgroup and highest Ca*P values and vitamin D therapy. Four out of five score 3 patients experienced overt vascular events and 4 out of 5 of the same subgroup experienced parathyroidectomy (PTX) before, during or after the TRP. CONCLUSIONS: In this preliminary study we can conclude that a) the possibility of dramatic worsening of VC during TRP is not a rare event and this feature has a strong clinical implication, b) PTX before TRP could remove at least one of the putative risk factors in patients waiting for TRP with suboptimal control with medical therapy.