Influence of immunogenicity on the efficacy of longterm treatment of spondyloarthritis with infliximab.

BACKGROUND: Infliximab (IFX) is a monoclonal antibody against tumour necrosis factor α that is effective for treating spondyloarthritis (SpA). However, after initial success of the drug some patients lose responsiveness or develop infusion reactions, which may be related to the development of antibodies against the drug. OBJECTIVE: To investigate the clinical relevance of antibodies to infliximab (ATI) formation in patients with SpA undergoing IFX treatment over a prolonged period. METHODS: 94 patients with SpA treated with IFX from 1999 to 2010 were studied. Their clinical characteristics, serum trough IFX levels and ATI status were evaluated for a mean of 6.99 (95% CI:6.28 to 7.7) years. Clinical activity and improvement were measured using the Ankylosing Spondylitis Disease Activity Score (ASDAS): inactive <1.3, moderate ≥1.3 and <2.1, high ≥2.1-≤3.5, and very high >3.5 at three time points (6 months, 12 months and >4 years). RESULTS: ATI were detected in 24 (25.5%) patients. The patients with ATI had higher ASDAS scores than those without ATI (2.55±0.89 vs 1.79±1.04, p=0.038 at 6 months; 1.95±0.67 vs 1.67±0.71, p=0.042 at 1 year; 2.52±0.99 vs 1.53±0.81, p=0.024 at >4 years). Eleven patients (12%) developed infusion-related reactions, and of these, ATI were present in eight patients (73%). The patients with infusion-related reactions had higher ATI titres (median 12 931 AU/ml, IQR 853-82 437) vs median 2454 AU/ml, IQR 449-7718, p=0.028) and shorter survival (4.25 years vs 8.19 years, p<0.001). ATI development occurred more frequently in the patients not receiving methotrexate (20/58 (34.5%) vs 4/36 (11.1%), p=0.011). CONCLUSION: In patients with SpA treated with IFX, ATI formation is associated with a poor clinical response, the appearance of infusion reactions and the discontinuation of treatment.

Involvement of G-463A MPO gene polymorphism in the response of postmenopausal women to hormone therapy.

OBJECTIVE: The aims of this work were to determine (1) the effects of estrogen plus progestogen therapy (EPT) and raloxifene on oxidative stress and cardiovascular risk biomarkers in postmenopausal women and (2) the involvement of the functional G-463A polymorphism of the myeloperoxidase (MPO) gene in the therapy responses. METHODS: Postmenopausal women (45-55 y old) were assigned to three groups receiving (1) EPT (continuous 50 µg transdermal estradiol daily and 200 mg/d micronized progesterone orally the first 14 d of each month; n = 21), (2) raloxifene (60 mg daily; n = 17), and (3) no treatment (control; n = 21). Blood and urine samples were taken before and after 6 months of therapy. Measurements were serum lipid profile, C-reactive intercellular adhesion molecule 1 (ICAM-1), α-tocopherol, γ-tocopherol, uric acid, total antioxidant activity (TAA), malondialdehyde, and urinary 1,4-dihydroxynonane-mercapturic acid (the major urinary 4-hydroxynonenal metabolite). The G-463A MPO polymorphism was analyzed by polymerase chain reaction and restriction fragment length polymorphism. RESULTS: EPT significantly decreased TAA and the levels of ICAM-1, not modifying other cardiovascular risk or oxidative stress markers. The raloxifene and control groups experienced no modifications in oxidative stress or endothelial dysfunction markers. The MPO genotype specifically influenced the outcomes in the EPT group. Thus, TAA decreased significantly in GG (high-expression genotype) homozygotes, whereas ICAM-1 levels were reduced in A allele carriers. CONCLUSIONS: EPT exerted a negative action on the serum oxidant/antioxidant balance in the MPO GG homozygotes and a positive effect on the ICAM-1 endothelial dysfunction marker in carriers of the low-expression A allele. This observation provides evidence of the importance of this polymorphism in the response to EPT.

Serum oxidizability and antioxidant status in patients undergoing in vitro fertilization.

OBJECTIVE: To evaluate the serum oxidizability and antioxidant status in women undergoing an in vitro fertilization (IVF) cycle and to assess the possible relationship of the oxidizability indexes with the pregnancy rate. DESIGN: Prospective, longitudinal study. SETTING: Public university and public university hospital. PATIENT(S): Systematically recruited cohort of 125 women undergoing either IVF or intracytoplasmic sperm injection (ICSI). INTERVENTION(S): Serum samples were collected before the beginning of the use of gonadotropins (basal) and the day of human chorionic gonadotropin (hCG) administration (final) during an IVF cycle. MAIN OUTCOME MEASURE(S): The Cu2+-induced serum oxidation in terms of the oxidation rate in the lag (Vlag) and propagation (Vmax) phases and the time at which the oxidation rate is maximal (tmax), and measurements of serum total antioxidant activity (TAA), tocopherol, hydrophilic antioxidants, malondialdehyde, and nitric oxide. RESULT(S): Albumin, urate, bilirubin, alpha-tocopherol and gamma-tocopherol, TAA, and tmax statistically significantly decreased after the IVF cycle. Conception cycles were associated with a serum more prone to oxidation compared with nonconception cycles. In multivariate logistic regression analysis, the difference (final-basal) of the oxidation index Vlag (OR 1.394) and the body mass index (OR 0.785) were independent predictors of pregnancy. CONCLUSION(S): Treatment with IVF induces the production of reactive oxygen species (ROS), which is reflected in a serum less protected against oxidation. The results also suggest a role for ROS in the occurrence of conception in IVF.