Human Leukocyte Antigen Compatibility and De Novo Donor-Specific Antibodies in Long-term Renal Transplant Patients With Stable Graft Function.

PURPOSE: De novo donor-specific antibodies (DSA) are associated with antibody-mediated rejection leading to late renal transplant failure. The aim of this study was to evaluate whether HLA compatibility is associated with sensitization along with other risk factors. METHODS: Eighty-nine stable renal transplant recipients (47 men) were studied. Patients were classified into 2 groups according to HLA compatibility between donor and recipient, group A (1-4/8 matches) and group B (5-8/8 matches). Cold ischemia time (CIT) and delayed graft function (DGF) were recorded along with time with a functional graft. Anti-HLA antibodies were detected using a Luminex single-antigen bead assay and were further classified into DSA and non-DSA. RESULTS: HLA group A consisted of 49 (56%) transplant recipients while 38 (44%) were classified to group B, with functional grafts for 10.9 ± 6.7 and 14.8 ± 8.5 years, respectively (P = .019). Group A patients had more anti-HLA antibodies than group Β (P = .001) and this correlation was retained for DSA patients. De novo anti-HLA were detected in 40 patients; DSA were detected in 19 (21.8%). DSA (+) patients had recorded with functional renal grafts for 11 ± 5 years, compared to 14.4 ± 8.6 years (P = .048) for anti-HLA negative patients. Increased CIT and DGF were associated with anti-HLA antibodies detection but no with DSA. CONCLUSION: HLA compatibility is probably correlated with DSA in a context of a more general anti-HLA sensitization, and both have a negative effect on long-term renal graft outcome.

Predictive factors of low HCO3- levels in peritoneal dialysis patients.

BACKGROUND: Metabolic acidosis is a major metabolic abnormality in end-stage renal disease (ESRD) and alkali is provided with dialysis treatment to patients on chronic peritoneal dialysis (CPD) to keep their acid-base balance within normal serum HCO3- levels. METHODS AND RESULTS: We examined the levels of venous serum HCO3- in 163 patients on CPD and the predictive factors for HCO3- levels low enough to indicate metabolic acidosis. The mean value for HCO3- was 26+/-2.4 mmol/l and for anion gap was 13.1+/-3.1 mEq/l. A serum bicarbonate concentration of less than 24 mmol/l, compatible with metabolic acidosis, was observed in 13.5% of the patients. In a multivariate analysis HCO3- levels were directly correlated with older age and use of CaCO3- as phosphate binders, and inversely associated with serum potassium, the use of sevelamer and low lactate dialysis solutions. Higher serum urea levels, the use of low lactate solutions and sevelamer instead of CaCO3 were significantly predictive factors for HCO3- levels < 24 mmol/l. CONCLUSIONS: Venous HCO3- and anion gap values were within the normal ranges in stable CPD patients. In 13.5% of them, however, chronic metabolic acidosis was observed based on venous HCO3- levels < 24 mmol/l. Dietary protein intake, the use of sevelamer and low (35 mmol/l) concentration of lactate in dialysis solutions are important predictive factors for chronic metabolic acidosis in these patients.

Hypertension in chronic hemodialysis patients: current view on pathophysiology and treatment.

BACKGROUND: Hypertension accounts for 65 - 85% of patients beginning dialysis, and dialysis alone controls hypertension in over 50% of patients. PATIENT AND METHODS: We have surveyed the status of BP control in 113 hemodialysis patients, 66 men and 47 women, aged 59 +/- 13 years old, with a mean duration on hemodialysis 42 +/- 44 months. The following measurements were recorded: predialysis mean arterial pressure (pre-MAP), post-dialysis MAP (post-MAP), percentage of change in MAP, pre-dialysis weight, post-dialysis weight, fluid removed by ultrafiltration during each dialysis session, interdialytic weight gain and excess weight over the desirable dry weight. RESULTS: Our results showed a hypertension prevalence of 59% (hypertension defined as pre-MAP +/- 110 mmHg). MAP was not different between men and women, and only 4.5% of patients had isolated systolic hypertension. All hypertensive patients were on treatment with antihypertensives. Reduction in post-MAP by > or = 5% (controlled by ultrafiltration) was found in 68.5% of hypertensive and in 87.5% of normotensive patients. Age, primary renal disease, time on dialysis and adequacy of dialysis were not correlated with pre-MAP. Excess volume and interdialytic weight gain were found to correlate with pre-MAP (p = 0.03). Also, the weekly dosage of EPO had a significant correlation with pre-MAP (p = 0.03). No differences were found among four classes of antihypertensive drugs regarding the BP control. Patients with hypertension requiring one drug achieved a significantly (p < 0.05) lower pre-MAP than the group of patients receiving three or more drugs. In conclusion, hemodialysis population shows high prevalence of hypertension, resistant to antihypertensive treatment. CONCLUSION: Current methods of hemodialysis are not effective in controlling BP. This implies that more insight into the role of excess volume and vasomotor systems in the pathogenesis of dialysis hypertension is warranted.