HLA‐C*06:02 allele can influence clinical efficacy of certolizumab pegol?

Psoriasis is a chronic inflammatory skin disease characterized by erythematous plaques with scales mainly localized at the elbows, knees, and the trunk, but, which can affect all skin areas including the scalp or genital area. To the date, many drugs are developed to treat this condition, in particular biological treatments are the most important therapy that are used to control the disease. We read with very interesting the paper published on January 16 by Sin et al regarding the role of the Human Leukocyte Antigen C06 (HLA-C*06) in Chinese patients with active peripheral type psoriatic arthritis. The authors enrolled 60 patients but only 47 patients were genotyping for HLA-C*06. The result showed HLA-C*07:02 was the most frequent allele (29.8%), followed by HLA-C*01 (26.6%). The frequency of HLA-C*06:02 alleles was similar to Chinese normal population. We present data from our study conducted in patients with psoriatic arthritis (PsA) and chronic plaque psoriasis treated with certolizumab pegol and despite previous methotrexate, cyclosporine, anti-inflammatory drugs (NSAIDs), and corticosteroids; other authors reported similar data in response to adalimumab and ustekinumab.


| INTRODUCTION
Psoriasis is a chronic inflammatory skin disease characterized by erythematous plaques with scales mainly localized at the elbows, knees, and the trunk, but, which can affect all skin areas including the scalp or genital area. To the date, many drugs are developed to treat this condition, in particular biological treatments are the most important therapy that are used to control the disease.
We read with very interesting the paper published on January 16 by Sin et al 1 regarding the role of the Human Leukocyte Antigen C06 (HLA-C*06) in Chinese patients with active peripheral type psoriatic arthritis. The authors enrolled 60 patients but only 47 patients were genotyping for HLA-C*06. The result showed HLA-C*07:02 was the most frequent allele (29.8%), followed by HLA-C*01 (26.6%). The frequency of HLA-C*06:02 alleles was similar to Chinese normal population. We present data from our study conducted in patients with psoriatic arthritis (PsA) and chronic plaque psoriasis treated with certolizumab pegol and despite previous methotrexate, cyclosporine, anti-inflammatory drugs (NSAIDs), and corticosteroids; other authors reported similar data in response to adalimumab and ustekinumab. 2,3

| METHODS
We reviewed data of 39 Caucasian patients genotyped for HLA-C*06, 18 out of 39 patients were naive to biologic treatment, all patients were evaluated by both rheumatologists and dermatologists for the diagnosis. In our cohort, 19 patients were male and 20 females, the mean age was 56.0 ± 12.1 years (mean ± SD) and the duration of the PsA disease was 6.7 ± 5.4 years ( Table 1).
The severity of psoriasis and response to treatment were evaluated using the Psoriasis Area and Severity Index (PASI) score at baseline and then at follow-up visits on weeks 12, 24, and 52. We evaluated the proportion of patients achieving ≥50% reduction in PASI score (PASI 50), a ≥75% reduction in PASI score (PASI 75), a ≥90% reduction in the PASI score (PASI 90), and a ≥100% reduction in the PASI score after 12, 24, and 52 weeks. We evaluated also the following variables: Disease Activity

| DISCUSSION
Our data suggest that only 26% of patients affected by psoriatic arthritis are carriers of the HLA-C*06 allele, in line with the data reported by Sin et al. Furthermore, HLA-C*06 allele seems not correlated with a higher disease severity or a better clinical outcome. On the other hand, a multiple biological treatment failure and a high heavy weight seem to be connected with a poor response to certolizumab pegol.

CONFLICT OF INTEREST
The authors declare no conflicts of interest. 28.9 ± 4.0