Evaluate the serum level of TWEAK in patients with AV and their relations before and after treatment with isotretinoin.

Acne vulgaris is a chronic inflammatory disease of the pilosebaceous follicles, characterized by comedones, papules, pustules, cysts, nodules, and occasionally scars. Its pathogenesis includes follicular hyperkeratinization, sebaceous hypersecretion due to androgen stimulation, follicular colonization by Propionibacterium acnes, immune and inflammatory responses. It affects the face, anterior chest, and upper back . Inflammation is regarded as a key component in the pathogenesis of acne . An increase in the activity of the pro inflammatory cytokine, interleukin (IL) 1, is observed before the beginning of hyperproliferation around the uninvolved follicles and is thought to trigger the activation of keratinocyte proliferation. Nuclear factor kappa beta (NF κβ) regulated mRNA gene levels of the cytokines tumour necrosis factor (TNF) α, IL 1 β, IL 8 and IL 10 levels also affected.

Isotretinoin (13-cis retinoic acid) is a synthetic analog of vitamin A. Its oral form is prescribed for severe cases which are resistant to other treatments.

Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) belongs to the TNF superfamily. It has an important role in the regulation of cell growth, apoptosis, angiogenesis, and immune reactions.

Inclusion Criteria:

• Patients classified according to the global acne grading system(GAGS) into moderate, severe, and very severe cases

Exclusion Criteria:

• Pregnant and lactating women, patients with renal, GIT, skeletal, psychiatric, and endocrine disorders, sarcoidosis, and patients receiving drugs such as diuretics, multivitamins, anticonvulsants, glucocorticoids, erythromycin, estrogen compound pill were excluded.