CD4 and interstitial lung disease: - Chest X ray, Pulmonary function test and HRCT chest: Lymphadenopathy and ILD, BAL fluid analysis raised CD4:CD8 ratio - Skin biopsy for diagnosis: non-necrotising epithelioid cell granulomas - Ultrasound abdomen and neck: size and texture of lymph nodes in neck and mesentery, organomegaly, nephrocalcinosis - Laboratory: elevated inflammatory markers such as erythrocyte sedimentation rate (ESR) and C Reactive protein (CRP), Serum Angiotensin Converting Enzyme (ACE), serum IL-2R levels, Serum Calcium, Urine Calcium:creatinine ratio - MRI Brain: for the diagnosis of Neurosarcoidosis