Subclinical inflammation in renal transplant recipients: impact of cyclosporine microemulsion versus tacrolimus

BACKGROUND

Renal insufficiency and renal transplant (RT) provoke a microinflammatory state that leads to increased atherosclerosis. It is not fully known whether calcineurin inhibitors (CNIs) play a role in the inflammation observed in these patients or whether any differences exist between CNIs.

OBJECTIVES

The study aimed to establish differences in the inflammatory state of two groups treated with cyclosporine microemulsion (CyA) or tacrolimus (TC).

PATIENTS AND METHODS

This prospective study included 81 RT patients divided into two groups according to the CNI: CyA group, n = 35 versus TC group, n = 46. The markers of inflammation (MIF) were determined preRT and at 3 and 12 months' postRT: C-reactive protein (CRP), serum amyloid protein A (SAA), interleukin-6 (IL-6), soluble interleukin-2 receptor (sIL-2R), tumor necrosis factor-alpha (TNF-alpha), and pregnancy-associated plasma protein A (PAPP-A). Samples were collected in stable patients in the absence of rejection, active infection, or inflammatory processes.

RESULTS

No significant differences existed between the markers of inflammation in the two treatment groups prior to transplantation. At 3 months' posttransplant, patients treated with CyA showed significantly higher levels of IL-6 (P = .05), SAA (P = .03), and sIL-2R (P = .008) compared with patients treated with TC. These differences were maintained for IL-6 (P = .03) and sIL-2R (P = .027) at 12 months' posttransplant. A multivariate analysis at 3 months showed that only age [OR 10.1; CI (95% 2.6-38.4); P = .001], SAA [OR 4.8; IC (95% 1.4-16.5); P = .015], and sIL-2R [OR 4.9; IC (95% 1.5-16.2); P = .009] were independent predictors of the CNI used. At 12 months, age [OR 3.7; IC (95% 0.9-14.2] and sIL-2R [OR 6.04; IC (95% 1.5-23); P = .006] continued to be independent predictors.

CONCLUSIONS

Patients treated with CyA displayed significantly higher levels of inflammatory markers (IL-6, SAA, sIL-2R) at 3 and 12 months' posttransplantation, independent of age, gender, time on dialysis, diabetes mellitus (preRT and de novo postRT), and renal function measured by serum creatinine.

Effect of low doses of atorvastatin on adiponectin, glucose homeostasis, and clinical inflammatory markers in kidney transplant recipients

INTRODUCTION

Various studies describe the pleiotropic antiinflammatory and antioxidant effects of atorvastatin, in addition to its hypolipemic effects. It has been suggested that statins modify glucose homeostasis via their antiinflammatory effects. A further hypothesis suggests that the incidence of posttransplantation diabetes is lower in statin-treated patients. This study sought to ascertain whether atorvastatin modifies glucose homeostasis, adiponectin, and inflammatory markers in kidney transplant recipients.

PATIENTS AND METHODS

Sixty-eight kidney transplant recipients (41 men, 27 women; mean age, 53 +/- 12 years) with stable renal function and dyslipidemia were treated with atorvastatin (10 mg/d) for 12 weeks. Glucose, insulin, homeostasis model assessment (HOMA-IR) index, adiponectin, tumor necrosis factor (TNF)-alpha, and serum C-reactive protein (CRP) concentrations were determined at baseline and at 3 months. The lipid profile, renal function parameters (creatinine, creatinine clearance, and proteinuria), as well as GOT, GPT, and CK were determined at baseline and at 3 months.

RESULTS

Treatment with atorvastatin achieved a statistically significant decrease in lipid profile. After 3 months of treatment, 74.6% of patients had total cholesterol and 78.7% low-density lipoprotein (LDL) cholesterol concentrations within reference range (<5.2 and 3.3 mmol/L, respectively). Furthermore, 47.5% of patients attained an LDL concentration <2.59 mmol/L. A greater reduction in total cholesterol (P = .05) and LDL cholesterol (P = .04) was achieved in patients with creatinine clearance <60 mL/min. Atorvastatin did not modify glucose homeostasis parameters, adiponectin, TNF-alpha, or CRP. At baseline and after 3 months of treatment, an inverse correlation was found between adiponectin and glucose, insulin, HOMA- IR index, and creatinine clearance, and a positive correlation was found between adiponectin and high-density lipoprotein (HDL) cholesterol.

CONCLUSION

Atorvastatin at a dose of 10 mg/d in kidney transplant recipients does not modify glucose homeostasis or alter inflammatory markers, despite its hypolipemic effects. Its efficacy to reduce total cholesterol and LDL cholesterol was greater in patients with worse renal function.

F2-Isoprostanes in Kidney Transplant Patients: Relationship With Inflammatory Markers

This prospective study evaluated the relationship between inflammation and oxidative stress in a group of dialysis patients just before and 3 months after kidney transplantation and compared the results with a control group of healthy subjects. The oxidative stress markers determined were different F2-isoprostane isomers. The inflammatory markers included C-reactive protein, interleukin-6, tumor necrosis factor-alpha, and pregnancy-associated plasma protein A. Forty-three patients were the study group and 50 healthy subjects from a hospital blood bank as controls. The results showed levels of inflammatory and oxidative stress markers to be higher in the dialysis patients than in the control group, although they improved following kidney transplantation. Finally, significant correlations were observed between F2-isoprostane isomers and inflammatory markers.

Diagnostic efficiency of serum IGF-I, IGF-binding protein-3 (IGFBP-3), IGF-I/IGFBP-3 molar ratio and urinary GH measurements in the diagnosis of adult GH deficiency: importance of an appropriate reference population

OBJECTIVE

To analyse the diagnostic role of serum IGF-I, IGF-binding protein-3 (IGFBP-3), IGF-I/IGFBP-3 molar ratio and urinary GH (uGH) excretion in adult GH deficiency (GHD).

DESIGN

Twenty-seven adults (age range: 18-71 years) with severe GHD, defined by a peak GH response to an insulin tolerance test below 3microg/l in patients with at least one additional pituitary hypofunction. Reference values were established from a selected age- and body mass index-matched population (154 healthy adults grouped in four age groups).

METHODS

IGF-I and IGFBP-3 were measured by RIA (Nichols) and results expressed as standard deviation (s.d.) scores from our reference population and assay normative data (s.d. score Nichols). uGH was measured by IRMA.

RESULTS

Within the control group, IGF-I, IGFBP-3, IGF-I/IGFBP-3 ratio standardisation regarding our control population and IGF-I with respect to the assay normative data resulted in disappearance of age-related differences. However, IGFBP-3 s.d. score Nichols resulted in mean values between +1.4 and +2.5 s.d. score. Greatest diagnostic efficiency was for IGF-I standardised with respect to our controls (97.2%), followed by s.d. score IGFBP-3 (92.9%). s.d. score IGF/IGFBP-3 ratio and uGH showed poor diagnostic efficiency. Any combination of at least two abnormal parameters raised specificity to 100%. IGF-I standardised with respect to assay reference (s.d. score Nichols) showed similar diagnostic value (95.0%) whereas IGFBP-3 showed low sensitivity (33. 3%). Within the GHD patients, those with three or more additional deficiencies had lower s.d. score IGF-I than those with only two or one.

CONCLUSION

We underline the importance of an appropriate reference population for correct interpretation of GH secretion markers. Considering our results, specificity obtained with two simultaneous abnormal parameters when referred to an adequate reference population may add valuable information to alternative GH stimulation tests to confirm adult GHD.

Growth hormone-binding protein directly depends on serum leptin levels in adults with different nutritional status

The aim of this work was to assess the relationship between GH-binding protein (GHBP) and leptin. Both peptides are nutritionally regulated, but the recent implication of a role for leptin in the GH axis requires further study. To avoid the sexual dimorphism in leptin values, we performed leptin standardization according to gender (SD score-leptin). The relationship between SD score-leptin and GHBP was studied in 128 adults with different nutritional status [8 groups according to body mass index (BMI)], ranging from severely underweight anorexia nervosa to highly morbid obesity. Both GHBP and SD score-leptin significantly increased according to BMI within the range from 18-27 kg/m2, whereas no significant differences were found among underweight groups (BMI, < 18 kg/m2) or among obesity grades (BMI, > 27 kg/m2). We found a strong correlation between GHBP and SD score-leptin (r = 0.8; P < 0.0001). Multiple regression analysis revealed SD score-leptin to be a significant determinant of GHBP, accounting for 64% of the variation, whereas BMI did not contribute further to explaining changes in GHBP. This suggests a physiological pathway involving both GHBP (the soluble fraction of GH receptor) and leptin. Thus, we might speculate that leptin could be the signal that induces the related nutritional changes observed in GHBP/GH receptor expression.

Analytical performance and clinical usefulness of two binding assays for growth hormone binding protein (GHBP) measurement: high performance liquid chromatography (HPLC)-gel filtration and dextran-coated charcoal adsorption

We compared two binding assays for growth hormone binding protein (GHBP) measurements, which differ in the method of bound and free GH separation: HPLC-gel filtration or dextran coated-charcoal adsorption (DCC). Two pools of sera (high and medium GHBP activity) were used for quality-control assessment. Moreover, 62 samples from 34 children and 28 adults with different nutritional status were studied. Total, between- and intra-iodination coefficients of variation (CVs) from the two methods were not different. Although percentage binding measured in the pool sera significantly differed, the concentrations assessed by Scatchard plot were comparable. Results obtained by the two methods in the 62 sera were significantly correlated (r = 0.77, P < 0.001). With both methods GHBP activity correlated with chronological age and body mass index (BMI) and differed among groups with different nutritional status. Although HPLC and DCC separation methods for GHBP measurement differ in their practicability, our study demonstrates that performance and the clinical usefulness of the two methods are comparable.