Longitudinal evaluation of mycophenolic acid pharmacokinetics in pediatric kidney transplant recipients. The role of post-transplant clinical and therapeutic variables.

This longitudinal study assessed the influence of post-transplant clinical and therapeutic variables in 50 kidney transplant recipients aged 2-19 yr receiving a triple immunosuppressive regimen consisting of cyclosporine microemulsion (CsA), steroids and MMF (300-400 mg/m(2) body surface area twice daily), the full pharmacokinetic profile (10 points) of which was investigated on post-transplant days 6, 30, 180 and 360. Total plasma MPA was measured by Enzyme Multiplied Immunoassay Technique. CsA therapeutic drug monitoring (TDM) was performed via C2 blood monitoring, while MPA TDM via C0. MPA Cmax, tmax, AUC0-12 and AUC0-4 pharmacokinetic profile changed significantly during the first post-transplant year. C0 was a poor predictor of the total MPA exposure [as measured by the area under the concentration-time curve AUC)], while a truncated AUC was a good surrogate of the 12-h profile (r = 0.91; p < 0.001) Graft function and cyclosporine therapy influenced MPA pharmacokinetics, as shown by the univariate and multivariate analyses. We conclude that because after transplantation MPA exposure varied over time, a strict TDM is advisable in the pediatric population.

Cytokine levels in sputum of cystic fibrosis patients before and after antibiotic therapy.

It is not known whether cytokine levels in sputum may be used as outcome measures after parenteral antibiotic therapy in cystic fibrosis (CF) patients. Here, we assessed the effects of antibiotic therapy on cytokine levels in sputum and serum obtained from young CF patients. Thirty-two CF patients (14 females; mean age, 18.6 years; range, 11.4-35.7 years), consecutively admitted at the CF Center of Milan for parenteral antibiotic therapy during pulmonary exacerbation, were enrolled in the study. Before and after 21 days (range, 5-41) of intravenous antibiotic treatment, all patients underwent routine laboratory determinations (including white blood cell (WBC) count and C-reactive protein (CRP)), a chest X-ray, pulmonary function tests (forced expiratory volume in 1 sec (FEV1) and forced vital capacity (FVC) as % predicted), and sputum cultures. Interleukin (IL)-6, IL-8, IL-10, and tumor necrosis factor (TNF)-alpha levels in serum and sputum samples were determined by means of immunometric assays. After therapy, FEV1 and FVC significantly improved (median increase of 7.5% and 8.5% predicted, respectively), while CRP and WBC count were significantly decreased (median values from 14 to 5.5 mg/dl and from 8,350 to 7,400 n/mm3, respectively). While levels of IL-6 and IL-10 in sputum were generally undetectable, IL-8 and TNF-alpha were always measurable, and IL-8 levels significantly decreased after antibiotic treatment (median values from 7,165 to 5,415 pg/ml). Following antibiotic therapy, IL-8 and TNF-alpha levels in sputum were inversely related with both FEV(1) and FVC. In conclusion, TNF-alpha and IL-8 levels in sputum of young CF patients with pulmonary exacerbation were always detectable and may be useful, noninvasive outcome measures to assess response to therapy in CF patients.

Impact of vitamin D administration on immunogenicity of trivalent inactivated influenza vaccine in previously unvaccinated children.

As vitamin D (VD) has a significant regulatory effect on innate and adaptive immunity, the aim of this prospective, randomized, single-blinded, placebo-controlled study was to measure the impact of VD administration on the immune response to trivalent influenza vaccination (TIV). A total of 116 children (61 males, 52.6%; mean age 3.0 ± 1.0 y) with a history of recurrent acute otitis media (AOM), who had not been previously vaccinated against influenza, were randomized to receive daily VD 1,000 IU or placebo by mouth for four months. All of them received two doses of TIV (Fluarix, GlaxoSmithKline Biologicals) one month apart, with the first dose administered when VD supplementation was started. There was no difference in seroconversion or seroprotection rates, or antibody titers, in relation to any of the three influenza vaccine antigens between the VD and placebo groups, independently of baseline and post-treatment VD levels. The safety profile was also similar in the two groups. These data indicate that the daily administration of VD 1,000 IU for four months from the time of the injection of the first dose of TIV does not significantly modify the antibody response evoked by influenza vaccine.

Vitamin D supplementation reduces the risk of acute otitis media in otitis-prone children.

BACKGROUND: The aim of this study was to evaluate whether a deficit in vitamin D (VD) is associated with an increased risk of recurrent acute otitis media (AOM) and whether VD supplementation is effective in reducing the number of AOM episodes in otitis-prone children. METHODS: A total of 116 children with a history of recurrent AOM (≥3 episodes in preceding 6 months or ≥4 episodes in preceding 12 months) were prospectively and blindly randomized to receive oral VD 1000 IU/d or placebo for 4 months. Episodes of AOM were monitored for 6 months. RESULTS: Fifty-eight children received placebo and 58 with similar characteristics were treated with VD. The number of children experiencing ≥1 AOM episode during the study period was significantly lower in the treatment group (26 versus 38; P = 0.03). There was a marked difference in the number of children who developed uncomplicated AOM (P < 0.001), but no difference in the number of children with ≥1 episode of spontaneous otorrhea. The likelihood of AOM was significantly reduced in the patients whose serum VD concentrations were ≥30 ng/mL. CONCLUSIONS: VD hypovitaminosis is common in children with recurrent AOM and associated with an increase in the occurrence of AOM when serum 25(OH)D levels are <30 ng/mL. The administration of VD in a dosage of 1000 IU/d restores serum values of ≥30 ng/mL in most cases and is associated with a significant reduction in the risk of uncomplicated AOM.

A biomarker of oxidative stress as a nontraditional risk factor in obese subjects.

BACKGROUND: Oxidative stress has been postulated as an additive factor linking obesity to cardiovascular disease. MATERIALS & METHODS: Derivatives of reactive oxygen species metabolites (d-ROMs) were measured in 136 obese (42 males, 94 females; mean age: 47 ± 12 years; BMI: 36 ± 5 kg/m(2)) and in 306 over- and normal-weight subjects (112 males, 194 females; age: 47 ± 12 years; BMI: 24 ± 3 kg/m(2)). RESULTS: d-ROMs levels were higher in obese than in over- and normal-weight subjects (395 ± 104 vs 362 ± 102 and 351 ± 84 arbitrary units (AU); p < 0.001), in women than males (390 ± 104 vs 327 ± 68 AU; p < 0.001), in subjects with than those without hypertension (390 ± 103 vs 360 ± 95 AU; p < 0.01) and in smokers than former and nonsmokers (380 ± 97 vs 358 ± 97 AU; p < 0.05). A positive correlation was found between d-ROMs and BMI (r = 0.25; p < 0.001) and age (r = 0.13; p < 0.01). Levels of d-ROM (>75th percentile: 420 AU) remained as an independent obesity predictor (odds ratio: 2.5; p < 0.001) in women. Continuous variables are reported as mean ± standard deviation. CONCLUSION: d-ROMs are a powerful obesity predictor, and could represent a reliable tool in obesity and cardiovascular risk evaluation, especially in women.

The effect of CYP3A5 polymorphisms on the pharmacokinetics of tacrolimus in adolescent kidney transplant recipients.

BACKGROUND: CYP3A5 gene polymorphism has been shown to influence tacrolimus (TAC) blood concentration and dose requirement in adult kidney transplant patients. The aim was to analyze retrospectively the modification induced by CYP3A5 gene polymorphism on TAC's pharmacokinetic parameters obtained from 26 adolescents receiving TAC as their main immunosuppressive drug. MATERIAL/METHODS: The adolescent kidney transplant patients were genotyped for CYP3A5*3 and grouped accordingly. TAC dose, blood levels, and dose-normalized TAC blood concentration and volume of distribution obtained at different post-transplant periods during the first post-transplant year were correlated with the corresponding genotype. RESULTS: During the first three months post-transplant, heterozygotes (CYP3A5*1/*3) displayed a lower TAC blood concentration than homozygotes (CYP3A5*3/*3) (at 1 month: 7.8+/-2.1 vs. 13.4+/-6 ng/ml, p=0.007) despite a therapeutic monitoring strategy. Between 3-12 months post-transplant, TAC blood concentration was comparable between the two groups, but a two-fold increase in the daily drug dose was necessary for the heterozygotes (at 6 months: 0.23+/-0.1 vs. 0.13+/-0.06 mg/kg, p=0.04). The dose-normalized TAC concentration [(ng/ml)/(mg/kg)] was significantly lower in patients displaying the CYP3A5*1/*3 polymorphism (at 2 weeks: 33+/-2.16 vs. 71.1+/-37.8, p=0.01; 6 months: 35.4+/-12.9 vs. 85.2+/-58.9, p=0.01). At the same time, the volume of distribution of the drug in the latter group was distinctly increased for the entire post-transplant year (at 6 months: 1.79+/-0.42 vs. 0.73+/-0.5 l/kg, p=0.001). CONCLUSIONS: The great influence of CYP3A5 on the pharmacokinetics and pharmacodynamics of TAC in young transplant recipients suggests the need for pre-transplant screening of this polymorphism to improve TAC therapy.