Effect of Oral Drug Apremilast on Histopathological Changes in Patients of Plaque Psoriasis: A Prospective Observational Study

Introduction: Psoriasis is a chronic non infectious recurrent papulosquamous inflammatory disorder characterised by vascular alterations such as angiogenesis, dilatation, increased endothelial venule generation, epidermal keratinocyte hyperproliferation, and aberrant differentiation, and lymphocytic invasion of T-cells. The aetiopathogenesis of disease is influenced by both hereditary and environmental factors. Pathogenesis is significantly influenced by immune dysregulation, which affects both innate and acquired immunity. A relatively recent medication for the management of moderate to severe plaque psoriasis is apremilast, an oral phosphodiesterase-4 inhibitor. Compared to other immune-suppressing drugs used in psoriasis apremilast causes no reactivation of tuberculosis or opportunistic infections, does not need dose adjustment in elderly or patients with hepatic impairment, and is not contraindicated in diabetes, ischaemic heart disease, or congestive cardiac failure. Due to its advantage of the absence of the need for laboratory monitoring, the patients on long-term methotrexate can also be switched to apremilast.

Aim: To evaluate the histopathological changes in the skin of all plaque psoriatic patients treated with oral drug apremilast.

Materials and Methods: This hospital-based prospective study was done in the Department of Pathology at the Rajasthan University of Health Sciences (RUHS), Jaipur, India for a period of one year from February 2020 to January 2021 comparing the efficacy of Apremilast clinically by evaluating plaque psoriasis patients’ by Psoriasis Area and Severity Index (PASI) scores. Patients of all age groups with a clinical diagnosis of psoriasis were subjected to a punch biopsy from an active lesion by a dermatologist. For histopathological examination, biopsy was taken from the lesion before starting treatment with apremilast and after four weeks of apremilast therapy. The subsequent changes in the form of histopathological score and PASI score were analysed and compared with the previous score to study the effect of oral drug apremilast.

Results: Total of 100 patients enrolled in the study with the mean age 39.14 years including 59% males and 41% females. Main site of lesion was back, hand and leg. The PASI score at the first visit was 11.28 and at the second visit were 7.27 with the improvement 35.54% which was statistically significant from first visit (p-value <0.001). The histopathological score at the first visit was 15.98 and at the second visit were 10.06 with the improvement 37.1%.

Conclusion: Apremilast was found to be a safe and effective treatment for psoriasis patients, and this impact was unaffected by confounding variables.