Ranitidine does not affect psoriasis: a multicenter, double-blind, placebo-controlled study

Ixekizumab-induced urticaria is associated with the short duration of remission in psoriasis by activation of mast cells

BACKGROUND

Mast cell degranulation plays a pivotal role in urticaria and is also an early histologic characteristic of psoriasis. However, whether the activation of mast cells contributes to psoriasis recurrence after discontinuation of interleukin (IL)-17A blockers remains unclear.

OBJECTIVE

To investigate the role of mast cells in ixekizumab treatment-associated urticaria (ITAUR) and assess the effect of urticaria eruption on psoriasis relapse.

METHODS

A retrospective analysis was performed on biopsies of patients who experienced psoriasis relapse after discontinuation of ixekizumab. Transcriptomic and histopathologic features were assessed. Patterns were compared between patients with ITAUR and nonurticaria (NUR) as well as psoriasis-like mice with mast cell activation or inactivation.

RESULTS

Patients with ITAUR experienced early relapse compared with NUR group after treatment withdrawal. Transcriptomic and histopathologic analyses revealed that patients with ITAUR had an elevated proportion of mast cells in resolved skin. Especially, the proportion of IL-17A+ mast cells was inversely correlated with the duration of remission.

LIMITATIONS

The mechanism of mast cell activation in ITAUR has not been precisely elucidated.

CONCLUSION

Ixekizumab treatment increases IL-17A+ mast cells in lesions of ITAUR, which is associated with early psoriasis relapse after ixekizumab withdrawal.

Addition of an oral histamine antagonist to reduce adverse events associated with fumaric acid esters in the treatment of psoriasis: a randomized double-blind placebo-controlled trial

BACKGROUND

Fumaric acid esters (FAEs) are considered an effective and safe long-term treatment for psoriasis. However, 30-40% of patients need to discontinue FAE treatment due to intolerable adverse events.

OBJECTIVES

To assess whether the addition of cetirizine, an oral histamine-1 receptor antagonist, to FAEs would reduce the incidence of adverse events.

METHODS

In a randomized, double-blind, placebo-controlled trial, patients with psoriasis with a Psoriasis Area and Severity Index ≥ 10 starting an FAE up to a dose of dimethylfumarate 720 mg per day were randomized 1 : 1 to receive either additional cetirizine 10 mg once daily (n = 25) or placebo (n = 25) for 12 weeks. Randomization and treatment allocation were done at our hospital trial pharmacy. Primary outcomes were the incidence of adverse events and the proportion of patients discontinuing treatment.

RESULTS

Fifty patients (33 male, 17 female; median age 44 years) were enrolled. Addition of cetirizine did not reduce the incidence of adverse events compared with placebo (84% vs. 84%, P = 1·00). The types of adverse events were not different between the cetirizine and placebo groups, the most common being gastrointestinal complaints (68% vs. 64%) and flushes (60% vs. 48%). The proportion of patients discontinuing treatment was not statistically different between the cetirizine and placebo groups (24% vs. 32%, P = 0·53).

CONCLUSIONS

Addition of oral cetirizine 10 mg once daily to FAE treatment did not reduce adverse events in patients with psoriasis during the first 12 weeks of treatment. The mechanisms underlying FAE-induced gastrointestinal and flushing symptoms likely involve mediators other than histamine.

Antihistamines and itch

Histamine is one of the best-characterized pruritogens in humans. It is known to play a role in pruritus associated with urticaria as well as ocular and nasal allergic reactions. Histamine mediates its effect via four receptors. Antihistamines that block the activation of the histamine H₁receptor, H₁R, have been shown to be effective therapeutics for the treatment of pruritus associated with urticaria, allergic rhinitis, and allergic conjunctivitis. However, their efficacy in other pruritic diseases such as atopic dermatitis and psoriasis is limited. The other histamine receptors may also play a role in pruritus, with the exception of the histamine H₂receptor, H₂R. Preclinical evidence indicates that local antagonism of the histamine H₃receptor, H₃R, can induce scratching perhaps via blocking inhibitory neuronal signals. The histamine H₄receptor, H₄R, has received a significant amount of attention as to its role in mediating pruritic signals. Indeed, it has now been shown that a selective H₄R antagonist can inhibit histamine-induced itch in humans. This clinical result, in conjunction with efficacy in various preclinical pruritus models, points to the therapeutic potential of H₄R antagonists for the treatment of pruritus not controlled by antihistamines that target the H₁R.

Triggering drug use in patients with psoriasis: an investigative report from Turkey

INTRODUCTION

The patients clinically diagnosed with psoriasis were investigated for drug use that may trigger psoriasis.

AIM

To minimize the triggering drug use and help the medical treatment of psoriasis patients.

MATERIAL AND METHODS

The study involved 289 psoriatic patients who attended our clinic in 2010-2012 and were asked to bring their drug lists of the last year, which they obtained from the pharmacy's record system. They were advised not to use the drugs that may trigger psoriasis. Data analyses were performed using SPSS program version 19.0.

RESULTS

A total of 289 patients were included in the study. Two hundred and twenty-one patients were using non-steroidal anti-inflammatory drugs; 133 patients were using anti-reflux drugs; 35 patients were using antidiabetic drugs; 31 patients were using calcium-channel blockers and 24 patients were using β-blockers. In our study group, there was no significantly difference between median PASI scores of the patients using a triggering drug and those of who are not using a triggering drug. However, there was a positive low correlation between PASI rates and numbers of drugs used (r = 0.180, p = 0.013).

CONCLUSIONS

Many other factors may trigger psoriasis, therefore the effect of stopping or minimizing the drug use on disease remission is not known. Because of the high triggering drug use rate, it is important to enlighten psoriasis patients about triggering drugs.

Is there a role for mast cells in psoriasis?

Mast cells have traditionally been considered as effector cells in allergy but during the last decade it has been realized that mast cells are essentially involved in the mechanisms of innate and acquired immunity. Upon activation by anaphylactic, piecemeal degranulation or degranulation-independent mechanisms mast cells can secrete rapidly or slowly a number of soluble mediators, such as serine proteinases, histamine, lipid-derived mediators, cytokines, chemokines and growth factors. Mast cells can express cell surface co-stimulatory receptors and ligands, and they can express MHC class II molecules and thereby present antigens. These soluble factors and cell surface molecules can interact with other cells, such as endothelial cells, keratinocytes, sensory nerves, neutrophils, T cell subsets and antigen presenting cells which are essential effectors in the development of skin inflammation. Besides promoting inflammation, mast cells may attempt in some circumstances to suppress the inflammation and epidermal growth but the regulation between suppressive and proinflammatory mechanisms is unclear. Psoriasis is characterized by epidermal hyperplasia and chronic inflammation where tryptase- and chymase-positive MC(TC) mast cells are activated early in the developing lesion and later the cells increase in number in the upper dermis with concomitant expression of cytokines and TNF superfamily ligands as well as increased contacts with neuropeptide-containing sensory nerves. Due to the intimate involvement of mast cells in immunity and chronic inflammation the role of mast cells in psoriasis is discussed in this review.

Rethinking the Psoriasis Area and Severity Index: the impact of area should be increased

BACKGROUND

The Psoriasis Area and Severity Index (PASI) is the most frequently used clinical severity scale in clinical trials. Drug approval often depends on a 75% improvement in the baseline PASI score, also known as a PASI 75 or Delta PASI 75. This benchmark may be an overly stringent way to determine the success of psoriasis treatments as Delta PASIs appear to under-represent true clinical improvement. This discrepancy may relate to the way numerical values are assigned to the degree of body surface area (BSA) involvement.

OBJECTIVES

To assess whether altering the BSA component of the PASI formula so that it is weighted more heavily will result in a calculated change in psoriasis severity that more closely reflects patient assessment of improvement. Models developed included the Psoriasis Log-based Area and Severity Index (PLASI), which assigns values to the BSA score based on a linear scale using logarithms to define the intervals, and the Psoriasis Exact Area and Severity Index (PEASI), which uses the actual BSA as the multiplicative factor in the area score.

METHODS

Data were abstracted retrospectively from two clinical trials involving psoriasis treatments that used the PASI. The same trained psoriasis graders were involved in both trials. In these trials, baseline and end-point PASI worksheets were completed that included the actual clinician-estimated BSA involvement (0-100%) for each of the four areas (head, upper extremities, trunk and lower extremities). In one of the trials, patients were asked to assess the percentage improvement in their psoriasis at the end of the treatment window. PASIs and Delta PASIs were recalculated based on the new models and all scoring systems were validated by analysing their relationship to patients' self-assessments.

RESULTS

Clinical improvements under the new grading systems translated into greater percentage changes than calculated using the Delta PASI formula. Specifically, the Delta PASI 50 translated to a Delta PLASI 57.2 and Delta PEASI 61.1; Delta PASI 75 was equivalent to Delta PLASI 85.7 and Delta PEASI 91.7. Importantly, Delta PASI tended to be systematically lower than patients' self-assessment, while Delta PLASI and Delta PEASI better matched patients' self-assessments using a best-fit model.

CONCLUSIONS

These results suggest that the Delta PASI underestimates percentage improvement when compared with measures of patient's self-assessment, while Delta PLASI and Delta PEASI correlate better. Prospective studies will have to be performed to confirm these relationships, but weighting BSA more heavily in the severity score may result in a more accurate reflection of clinical status.