Hemolysis in G-6-P-D deficiency is precipitated by following, except:
**Core Concept**
Glucose-6-phosphate dehydrogenase (G-6-PD) deficiency is a genetic disorder that affects the enzyme glucose-6-phosphate dehydrogenase in red blood cells. This enzyme plays a crucial role in maintaining the integrity of red blood cells by protecting them from oxidative stress. In individuals with G-6-PD deficiency, the enzyme is either absent or present in low amounts, making their red blood cells more susceptible to hemolysis.
**Why the Correct Answer is Right**
Hemolysis in G-6-PD deficiency is precipitated by oxidative stress, which can be caused by various factors such as infections, certain medications, and exposure to certain substances like primaquine. The oxidative stress leads to the accumulation of glutathione disulfide, which in turn causes the denaturation of hemoglobin and ultimately leads to the destruction of red blood cells. This process is often referred to as oxidative hemolysis.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because infections, such as malaria, can indeed precipitate hemolysis in G-6-PD deficiency. The oxidative stress generated by the infection can overwhelm the limited amount of G-6-PD enzyme present in the red blood cells, leading to hemolysis.
* **Option B:** This option is incorrect because certain medications, such as primaquine, can precipitate hemolysis in G-6-PD deficiency. Primaquine is a well-known trigger for hemolysis in individuals with this deficiency.
* **Option D:** This option is incorrect because exposure to certain substances, such as fava beans, can also precipitate hemolysis in G-6-PD deficiency. The exact mechanism is not fully understood, but it is thought to involve the release of oxidative stress-inducing compounds from the beans.
**Clinical Pearl / High-Yield Fact**
Individuals with G-6-PD deficiency should avoid certain medications and substances that can precipitate hemolysis. It is essential to screen for G-6-PD deficiency before administering primaquine or other medications that may trigger hemolysis.
**Correct Answer:** A.