Naegler’s reaction is due to which toxin of Cl perfringens –
**Core Concept**
Naegler's reaction is a type of leukocytosis or increase in white blood cell count in response to a toxin, specifically associated with Clostridium perfringens (C. perfringens) infections. This reaction is mediated by alpha toxin, also known as phospholipase C, which is produced by C. perfringens.
**Why the Correct Answer is Right**
The alpha toxin of C. perfringens is responsible for causing tissue damage by breaking down phospholipids in cell membranes, leading to cell lysis and the release of cellular contents, including histamine. Histamine is a potent vasodilator that causes blood vessels to dilate, leading to increased blood flow and permeability, which results in edema and increased white blood cell count. This is the mechanism behind Naegler's reaction.
**Why Each Wrong Option is Incorrect**
**Option A:** is incorrect because it is not related to the toxin responsible for Naegler's reaction.
**Option B:** is incorrect because it is not a known toxin associated with C. perfringens.
**Clinical Pearl / High-Yield Fact**
Naegler's reaction is a classic example of a type III hypersensitivity reaction, where the release of histamine and other mediators leads to increased vascular permeability and leukocytosis. This reaction is often seen in the context of C. perfringens infections, particularly gas gangrene.
**Correct Answer:** C. Alpha toxin.