Evidence for Nevirapine Bioactivation in Man: Searching for the First Step in the Mechanism of Nevirapine Toxicity

Despite its efficacy, including in the prevention of vertical transmission, the antiretroviral nevirapine is associated with severe idiosyncratic hepatotoxicity and skin rash. The mechanisms underlying nevirapine toxicity are not fully understood, but drug bioactivation to reactive metabolites capable of forming stable protein adducts is thought to be involved. This hypothesis is based on the paradigm that drug reactive metabolites have the potential to bind to self-proteins, which results in drug-modified proteins being perceived as foreign by the immune system. The aim of the present work was to identify hemoglobin adducts in HIV patients as biomarkers of nevirapine haptenation upon bioactivation. The ultimate goal is to develop diagnostic methods for predicting the onset of nevirapine-induced toxic reactions. All included subjects were adults on nevirapine-containing antiretroviral therapy for at least 1month. The protocol received prior approval from the Hospital Ethics Committees and patients gave their written informed consent. Nevirapine-derived adducts with the N-terminal valine of hemoglobin were analyzed by an established liquid chromatography-electrospray ionization-tandem mass spectrometry method and characterized on the basis of retention time and mass spectrometric fragmentation pattern by comparison with adduct standards prepared synthetically. The nevirapine adducts were detected in 12/13 patient samples, and quantified in 11/12 samples (2.58±0.8 fmol/g of hemoglobin). This work represents the first evidence of nevirapine-protein adduct formation in man and confirms the ability of nevirapine to modify self-proteins, thus providing clues to the molecular mechanisms underlying nevirapine toxicity. Moreover, the possibility of assessing nevirapine-protein adduct levels has the potential to become useful for predicting the onset of nevirapine-induced adverse reactions.

Compliance with ESPGHAN Position on Complementary Feeding in a Multicultural European Community. Does Ethnicity Matter?

Introduction: In 2008, ESPGHAN published a position paper on complementary feeding providing recommendations to health care professionals. Cultural and socio-economic factors might affect the compliance to these orientations. Aim: To estimate the prevalence of inadequacies during complementary feeding (ESPGHAN, 2008) and its association with different ethnic backgrounds. Methods: Cross-sectional survey of a convenience sample of caretakers of children up to 24 months of age in a single community health centre in Greater Lisbon, through a volunteer, self-applied questionnaire. Results: From a sample of children with wide cultural diversity, 161 valid questionnaires were obtained (median child’s age 9 months, median mother’s age 32 years). The prevalence rate of at least one complementary feeding inadequacy was 46% (95%CI: 38.45-53.66). The commonest inadequacies were: avoiding lumpy solid foods after 10 months of age (66.7%), avoidance or delayed introduction of foods beyond 12 months (35.4%), introduction of gluten beyond 7 months (15.9%) or salt before 12 months (6.7%). For each increase of 1 month in the age of the child, the odds of inadequacies raised 36.7% (OR = 1.37; 95%CI: 1.20-1.56; p < 0.001). The odds for inadequacies in children of African or Brazilian offspring was three times higher that of Portuguese ancestry (OR = 3.31; 95%CI: 0.87-12.61; p = 0.079). The influence of grandparents was related to an increase in the odds of inadequacies (OR = 3.69; 95%CI: 0.96-14.18; p = 0.058).Conclusion: Inadequacies during complementary feeding are frequent and may be influenced by the cultural background.

Serum Trace Elements in Dysphagic Gastrostomy Candidates Before Endoscopic Gastrostomy for Long Term Enteral Feeding

BACKGROUND & AIMS: Patients who underwent endoscopic gastrostomy (PEG) present protein-energy malnutrition, but little is known about Trace Elements (TE), Zinc (Zn), Copper (Cu), Selenium (Se), Iron (Fe), Chromium (Cr). Our aim was the evaluation of serum TE in patients who underwent PEG and its relationship with serum proteins, BMI and nature of underlying disorder. METHODS: A prospective observational study was performed collecting: patient's age, gender, underlying disorder, NRS-2002, BMI, serum albumin, transferrin and TE concentration. We used ferrozine colorimetric method for Fe; Inductively Coupled Plasma-Atomic Emission Spectroscopy for Zn/Cu; Furnace Atomic Absorption Spectroscopy for Se/Cr. The patients were divided into head and neck cancer (HNC) and neurological dysphagia (ND). RESULTS: 146 patients (89 males), 21-95 years: HNC-56; ND-90. Low BMI in 78. Low values mostly for Zn (n = 122) and Fe (n = 69), but less for Se (n = 31), Cu (n = 16), Cr (n = 7); low albumin in 77, low transferrin in 94 and 66 with both proteins low. Significant differences between the groups of underlying disease only for Zn (t140.326 = -2,642, p < 0.01) and a correlation between proteins and TE respectively albumin and Zn (r = 0.197, p = 0.025), and albumin and Fe (r = 0.415, p = 0.000). CONCLUSIONS: When gastrostomy was performed, patients display low serum TE namely Zn, but also Fe, less striking regarding others TE. It was related with prolonged fasting, whatever the underlying disease. Low proteins were associated with low TE. Teams taking care of PEG-patients should use Zn supplementation and include other TE evaluation as part of the nutritional assessment of PEG candidates.