The lepromin (Mitsuda) test injected intradermally into a suspected leprosy patient is best interpreted as:
- A A diagnostic test confirming active infection with Mycobacterium leprae
- B An indicator of the host's cell-mediated immune resistance to M. leprae, useful for classification and prognosis ✓
- C A measure of the total bacillary load in the body
- D A serological test detecting anti-PGL-1 antibodies
Correct answer: B. An indicator of the host's cell-mediated immune resistance to M. leprae, useful for classification and prognosis
Explanation
The lepromin test uses killed M. leprae antigen and measures delayed-type hypersensitivity, reflecting the individual's capacity for cell-mediated immunity against the bacillus. It is strongly positive in tuberculoid leprosy and negative in lepromatous leprosy, so it helps classify disease and predict prognosis, including risk of reactions. It is neither diagnostic nor a measure of bacillary load, since it can be positive in exposed healthy individuals and negative in active lepromatous disease.
Reference: IAL Textbook of Leprosy, 2nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.