The Pharmacogenetic Footprint of ACE Inhibition: A Population-Based Metabolomics Study

Angiotensin-I-converting enzyme (ACE) inhibitors are an important class of antihypertensives whose action on the human organism is still not fully understood. Although it is known that ACE especially cleaves COOH-terminal dipeptides from active polypeptides, the whole range of substrates and products is still unknown. When analyzing the action of ACE inhibitors, effects of genetic variation on metabolism need to be considered since genetic variance in the ACE gene locus was found to be associated with ACE-concentration in blood as well as with changes in the metabolic profiles of a general population. To investigate the interactions between genetic variance at the ACE-locus and the influence of ACE-therapy on the metabolic status we analyzed 517 metabolites in 1,361 participants from the KORA F4 study. We replicated our results in 1,964 individuals from TwinsUK. We observed differences in the concentration of five dipeptides and three ratios of di- and oligopeptides between ACE inhibitor users and non-users that were genotype dependent. Such changes in the concentration affected major homozygotes, and to a lesser extent heterozygotes, while minor homozygotes showed no or only small changes in the metabolite status. Two of these resulting dipeptides, namely aspartylphenylalanine and phenylalanylserine, showed significant associations with blood pressure which qualifies them—and perhaps also the other dipeptides—as readouts of ACE-activity. Since so far ACE activity measurement is substrate specific due to the usage of only one oligopeptide, taking several dipeptides as potential products of ACE into account may provide a broader picture of the ACE activity.

The application of multiple quality-of-life instruments in individuals with mild-to-moderate psoriasis

The 36-item Short-Form Health Survey Questionnaire (HSQ SF-36), Psoriasis Disability Index (PDI), and Dermatology Life Quality Index (DLQI) were administered to individuals with mild-to-moderate psoriasis to validate the general quality-of-life instrument against the dermatosis-specific, and the dermatology-specific, disability measure. The population consisted of 644 adults with psoriasis involving up to 20% of the body surface area, who were enrolled in 2 US multicentre, evaluator-blinded, parallel-group clinical trials for a new psoriasis medication. Patients averaged 16.5% of maximum possible disability as measured by the PDI, and 23.4% of maximum possible disability as measured by the DLQI. Normalised T-scores showed that the patients approximated US population means on all 8 of the HSQ SF-36 dimensions. The HSQ SF-36 scales did not reflect substantial quality-of-life impairment, although all showed statistically significant correlations with both the PDI and DLQI (correlation coefficients ranging from -0.13 to -0.45). Moreover, while the disability indices were more responsive to psoriasis characteristics than the HSQ SF-36 quality-of-life scales, all 8 HSQ SF-36 dimensions demonstrated sensitivity to at least some objective and/or subjective ratings of severity. The strongest relationships were observed between the PDI, DLQI and the HSQ SF-36 Mental Health and Social Functioning dimensions, suggesting that the HSQ SF-36 is sensitive to psychosocial suffering related to psoriasis, which is not conveyed in objective clinical measures of severity.

Calcipotriene ointment 0.005% for psoriasis: a safety and efficacy study. Calcipotriene Study Group

BACKGROUND

Plaque psoriasis of mild to moderate severity is routinely treated with topical steroids and coal tar along with emollients. A safe and convenient new treatment modality would be of value to most patients with psoriasis.

OBJECTIVE

Our purpose was to evaluate the safety and efficacy of a new vitamin D3 analogue, calcipotriene, for the treatment of plaque psoriasis.

METHODS

Twice-daily dosing of calcipotriene was compared with its vehicle, for up to 8 weeks, in a double-blind study of 277 patients at 10 study centers in the United States. Two hundred forty-seven patients completed the trial. The clinical characteristics of plaque elevation, erythema, scaling, and overall disease severity were evaluated at baseline and after 1, 2, 4, 6, and 8 weeks of treatment. A Physician's Global Assessment of improvement or worsening of the disease was performed after 1, 2, 4, 6, and 8 weeks of treatment. Blood and urine samples, for routine clinical laboratory tests, were collected at baseline and after 1, 2, 4, and 8 weeks of treatment.

RESULTS

As early as the week 1 evaluation, patients treated with calcipotriene ointment 0.005% had significantly lower mean scores (p = 0.043) than the vehicle-treated patients for the disease characteristics of plaque elevation, erythema, and scaling. This trend continued through week 8 of treatment when 70% of the calcipotriene-treated patients showed 75% or more improvement compared with only 19% of vehicle-treated patients. Only minor treatment-related adverse events were observed. There were no abnormal laboratory results judged related to treatment and the rare instances of elevated serum calcium values were equally distributed between active and vehicle treatments.

CONCLUSION

This study provides evidence that calcipotriene is a safe, effective, and promising new agent for the treatment of moderately severe plaque psoriasis.