The Mitsuda reaction (lepromin test — late reaction) is used to assess:
- A Past exposure to Mycobacterium leprae (diagnostic test)
- B Specific antibody response to M. leprae PGL-1 antigen
- C Cell-mediated immunity (CMI) and prognosis in leprosy ✓
- D Drug sensitivity of M. leprae to dapsone
Correct answer: C. Cell-mediated immunity (CMI) and prognosis in leprosy
Explanation
The Mitsuda reaction (late lepromin reaction at 28 days) reflects cell-mediated immunity (CMI) to M. leprae antigens; it is strongly positive in tuberculoid leprosy (high CMI) and negative in lepromatous leprosy (poor CMI), correlating with prognosis. It is NOT diagnostic (healthy non-exposed individuals also give a positive reaction) but is a prognostic and immunological classification tool. PGL-1 antibody serology (ELISA) tests for antibody response, positive in lepromatous disease. The lepromin test cannot detect drug sensitivity.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.