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Background: Psoriasisis a chronic disease of the skin of unknown etiology that is characterised bychronic relapsing nature and variable clinical features. Since histopathological study gives the exact diagnosis of psoriasis & can differentiate it from other histological mimics, present study was aimed to study histopathological features of epidermal and dermal changes in lesionaland perilesional biopsies of psoriasis cases at a tertiary center.Materials and Methods:Present study was single-center, prospective, observational study, conducted in patients with clinical features of psoriasis, not received treatment for the past, skin biopsies were taken from both lesional& perilesional areas of psoriatic patients, H & E staining was done. Results:Among 52 cases, majority of patients were from the age group 31-40 years (40.3 %), and maleto female patient ratio was 2.7:1.Clinically, common features were macules/papules/plaques (100 %), moderate-severe itching (80.7%), nail involvement (61.5 %), nail pitting (40.3%), subungual hyperkeratosis (17.3%), nail discolouration (3.84%), Koebner phenomenon (23%), Auspitz sign (75%). Among 8 cases of early lesions, common features observed were parakeratosis (100%) mild to moderate acanthosis (100%), dilated capillaries and perivascular cellular infiltrate (100%), thinning of supra papillary plate (50%), Munro micro abscess (50%), spongiosis (37.5%).

Cell-mediated immunity is a key weapon of host defence against tuberculosis (TB). Granzyme A (GzmA), a serine protease, present in the granules of cytotoxic cells induces caspase-independent cell death. We estimated the proportion of GzmA producing lymphocyte subsets in peripheral blood from 59 normal healthy volunteers and 48 pulmonary TB (PTB) patients using flow cytometry. When compared with normal healthy subjects, we observed a significantly higher percentage of GzmA-positive CD56⁺ cells (P = 0.01) in PTB patients. However, when the absolute number was compared between the two groups, a significantly decreased number of GzmA-expressing CD16⁺ (P = 0.01) and CD56⁺ (P = 0.0001) cells was observed in patients and this could be explained by the significantly reduced number of total lymphocytes (P = 0.0009) seen in the patients. There was no significant difference in the number of CD4⁺ and CD8⁺ GzmA double-positive cells between the two study groups. CD56 is a natural killer cell marker and these cells represent innate immune response to TB. We report an increased percentage of CD56⁺ cells expressing GzmA in TB patients, which shows the relevance of the GzmA-mediated pathway of apoptosis in immunity against Mycobacterium tuberculosis.

Perforin is one of the major effector molecules of cytotoxic cells associated with killing of cells harbouring intracellular bacterial infection. The precise role of perforin positive cells in tuberculosis still remains controversial. The present study was done to determine the number of circulating CD4(+) and CD8(+) perforin positive cells to assess the level of cytotoxic response against Mycobacterium tuberculosis in patients with pulmonary tuberculosis. Intracellular perforin and surface CD4 and CD8 staining of peripheral blood lymphocytes was done using specific monoclonal antibodies and enumerated using flowcytometry. A significantly decreased total lymphocytes (P<0.01), CD4 (P<0.001) and CD8 (P<0.01) lymphocyte counts in PTB patients was observed compared to normal healthy individuals (NHS). Intracellular perforin staining showed significantly elevated percentages of total (P<0.05) and CD8 (P<0.01) perforin positive cells in PTB patients compared to NHS. However, the absolute counts of total, CD4 and CD8 cells positive for perforin were similar in patients and NHS. Our results suggest that during active stage of pulmonary tuberculosis there was an increased percentage of CD8 cells positive for perforin, irrespective of their absolute counts. Further, CD8(+) perforin positive cells may have increased cytolytic activity against M. tuberculosis in active pulmonary tuberculosis.