Objective
Vitamin E provides cardiovascular protection to individuals with Diabetes and the haptoglobin 2-2 genotype but appears to increase cardiovascular risk in individuals with Diabetes and the haptoglobin 2-1 genotype. We have previously demonstrated that the haptoglobin protein is associated with HDL and that HDL function and its oxidative modification are haptoglobin genotype dependent. We set out to test the hypothesis that the pharmacogenetic interaction between the haptoglobin genotype on cardiovascular risk might be secondary to a parallel interaction between the haptoglobin genotype and vitamin E on HDL function.
Research design and methods
Fifty-nine individuals with Diabetes and the haptoglobin 2-1 or 2-2 genotypes were studied in a double-blind placebo controlled crossover design. Participants were treated with either vitamin E (400 IU) or placebo for 3 months and crossed over for an equivalent duration. Serum was collected at baseline and after the completion of each treatment. HDL functionality as well as HDL associated markers of oxidation and inflammation were measured after each interval in HDL purified from the cohort.
Results
Compared to placebo, vitamin E significantly increased HDL function in haptoglobin 2-2 but significantly decreased HDL function in haptoglobin 2-1. This pharmacogenetic interaction was paralleled by similar non-significant trends in HDL associated lipid peroxides, glutathione peroxidase, and inflammatory cargo.
Conclusion
There exists a pharmacogenetic interaction between the haptoglobin genotype and vitamin E on HDL function. (clinicaltrials.gov NCT01113671).
Objectives
Rheumatoid arthritis (RA) has been rarely reported in association with sickle cell disease (SCD). Our study aimed to estimate the prevalence of RA in SCD population and to describe the clinical characteristics of RA associated with SCD.
Methods
Retrospective chart review of SCD and RA patients followed at 2 large urban hospitals. Seven RA/SCD patients were identified and compared to age and sex matched cohort of SCD only and of RA only group. All patients were Black.
Results
There were 739 SCD cases, seven (0.94%) met ACR criteria for RA (SCD-RA), 411 cases were RA only group. Mean age was significantly higher in SCD-RA compared to the entire population of SCD and RA (41.7 ± 3.9 (± SEM) vs. 33.26 ± 0.47, vs. 61.39 ± 0.79, p<0.01).
SCD-RA patients had lower hemoglobin (g/dl) when compared to the age and sex matched SCD or RA only patients (7.4 ± 0.49 vs. 8.3 ± 0.60 vs. 11 ± 0.59, p <0.01) respectively.
There were no significant differences in laboratory and treatment approach between SCD-RA and RA only groups, except for the radiographic evidence of periarticular osteopenia and greater difficulty in the activities of daily living (ADL) among SCD-RA cohort, compared to the age and sex matched RA cohort (p=0.01)
Conclusion
In contrast to older reports, the prevalence of RA among SCD patients in our study (0.94%) was similar to that reported in the general population (0.5–1%) and was to be associated with difficulty in ADL and periarticular osteopenia. Since RA manifests at an older age, our reported prevalence is likely explainable by improved survival of SCD patients due to enhanced medical care and the advent of hydroxyurea as a major therapeutic breakthrough for SCD.
The advent of hydroxyurea and advanced medical care, including immunizations has led to improved survival among patients with Sickle Cell Disease (SCD). This prolonged survival however, introduces a chronic inflammatory disorder, Rheumatoid Arthritis (RA), which presents at a relatively older age and is rarely reported among SCD patients. In this review, we highlight the epidemiological association of SCD-RA and discuss the underlying common pathogenetic mechanisms, such as endothelial dysfunction, the role of inflammatory cytokines and oxidative stress. We also point to the difficulties in ascertaining the clinical diagnosis of RA in SCD patients. Finally, we provide rationale for therapeutic options available for RA and the challenges in the management of these patients with agents that are known to increase the risk of infection and immunosuppression such as steroids, disease modifying anti-rheumatic drugs and biologics.
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