**Question:** Which of the following is the most prominent feature of immunoproliferative small intestinal disease (IPSID)?

A. Hypergammaglobulinemia
B. Autoimmune gastritis
C. Autoimmune thyroid disease
D. Chronic lymphocytic leukaemia

**Core Concept:** Immunoproliferative small intestinal disease (IPSID) is a rare disorder characterized by the proliferation of lymphocytes in the small intestine. It is associated with the development of autoimmune disorders and hypergammaglobulinemia, which is an elevated level of immunoglobulins in the blood.

**Why the Correct Answer is Right:** The most prominent feature of IPSID is **Hypergammaglobulinemia** (elevated immunoglobulins) due to the increased production of B cells and subsequent increased production of antibodies.

**Why Each Wrong Option is Incorrect:**

A. **Hypergammaglobulinemia** is not a prominent feature of IPSID; it is the result of the disorder, not a feature itself.
B. **Autoimmune gastritis** is a condition affecting the stomach, while IPSID primarily affects the small intestine.
C. **Autoimmune thyroid disease** is unrelated to IPSID, with no direct connection between the two conditions.
D. **Chronic lymphocytic leukaemia** is a separate entity characterized by the proliferation of lymphocytes in the blood and bone marrow, not the small intestine.

**Clinical Pearl:** IPSID is a complex disorder involving the small intestine and immune system. Understanding the relationship between its features, such as hypergammaglobulinemia, is crucial for accurate diagnosis and management of the condition.