Is psoriasis an autoimmune disease? Interpretations from an immunofluorescence-based study

Psoriasis is a multisystem, immune-mediated inflammatory disease. Some authors have proposed an autoimmune basis for psoriasis; however, till date, it has not been definitely established. This study was conducted to explore the autoimmune nature of psoriasis.

This was a prospective study in which 43 psoriasis patients were assessed for detailed clinical, histopathological and immunopathological features to explore the diagnostic utility of subtypes, intensity and number of immunoreactants in lesional and non-lesional skin in these patients. In addition, the sera of these patients were analyzed for the presence of various autoantibodies.

The patients' age ranged from 14 to 75 years with a male-to-female ratio of 1.52:1. Nine patients (20.93%) were positive for antinuclear and 2 (4.65%) for antismooth muscle antibodies. Direct immunofluorescence (DIF) was positive in 31 (72%) biopsies from the lesional and 27 (63%) biopsies from non-lesional skin. In all these DIF positive cases, granular deposits of C5b-9 were detected at the dermoepidermal junction. No significant difference was observed on comparing the type and pattern of immunoreactant positivity, among lesional and non-lesional skin biopsies (P > .05).

No significant association between psoriasis and immunoreactant deposition as well as autoantibody seroprevalence was observed, thereby refuting a definite autoimmune basis for psoriasis.