Circulating levels of chemokines in patients with psoriasis vulgaris and their association with disease severity: A case-control study from North India

Background: Psoriasis is a chronic inflammatory skin disease characterized by hyperproliferation and incomplete differentiation of epidermis, and accumulation of neutrophils and proinflammatory T cells in epidermis and dermis. Chemokines are believed to be the main players mediating the chemotaxis of leucocytes to the lesional site. Previous studies have established the role of various chemokine ligands and receptors at the lesional site in psoriasis.

Aims: In this study, we have compared the serum levels of various chemokines, namely, inducible protein-10 (IP-10) (CXCL10), MCP-1 (CCL-2), monokine induced by gamma interferon (MIG) (CXCL-9), RANTES (CCL5), interleukin (IL)-8, and eotaxin in patients with chronic plaque psoriasis with that of healthy controls. We also studied whether the chemokine levels varied within different patient groups based on various clinical and demographic parameters, and if any of these chemokines correlated with disease activity.

Methods: We studied 40 patients with chronic plaque psoriasis from a single center. Their clinical and demographic details were recorded in predesigned prforma. Patients with unstable forms of psoriasis like guttate, erythrodermic, or pustular psoriasis were excluded. The serum chemokine levels were measured by flow cytometry-based bead array set system. The serum levels of the patients were compared with that of 25 healthy controls. A subgroup analysis was also done to study the correlation of chemokine levels with age, sex, duration, and severity of disease.

Results: We observed a significant decrease in serum level of all these chemokines in patients, when compared with that of healthy controls. We also found that MIG levels showed a positive correlation with disease severity based on Psoriasis Area and Severity Index.

Limitations: The major limitation of the study is lack of data on the lesional chemokine levels compared to serum chemokines.

Conclusion: The inflammatory process in psoriasis is orchestrated through chemokines. MIG is a potential serum biomarker for assessing disease severity.