You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is A 32 year old man presents with a 3-month history of weight loss, night sweats, a productive cough with blood-tinged sputum, anorexia, general malaise, and a low grade fever. A PPD skin test shows > 10 mm of induration. If the area of induration were biopsied, which of the following type of reactive cells would be found? and explain in detail?
The CD4+ population of T lymphocytes, specifically TH1 cells, are responsible for the delayed hypersensitivity reaction seen with a skin test in a previously sensitized patient. The clinical pattern in the test question is classic for reactivation or adult-type tuberculosis. B lymphocytes are involved in humoral immune reactions. Antibody production is not a feature of tuberculin hypersensitivity. Eosinophils are impoant in type I hypersensitivity reactions and in immune mediated responses to parasitic infections (ADCC). They are not associated with tuberculin hypersensitivity. Mast cells are tissue cells which are involved in type I hypersensitivity reactions. They have surface receptors for the Fc fragment of the IgE molecule.