Which of the following clinical manifestations is a common symptom of primary immunodeficiency disorders?

Explanation: The correct answer is c. Flow cytometry. Flow cytometry is a specialized test used to analyze the different cell types in a blood sample. In the case of SCID, flow cytometry can help identify the absence or severe deficiency of T cells and B cells, which are essential components of the immune system.

Incorrect choices:

a. A tuberculin skin test (TST) is used to detect exposure to tuberculosis (TB) and is not specific to diagnosing SCID.

b. A Western blot test is a type of immunoassay used to detect specific antibodies or antigens in the blood but is not specific to diagnosing SCID.

d. Liver function tests are used to assess the health of the liver and are not specific to diagnosing SCID.

Explanation: The correct answer is c. Autoimmune diseases are a potential complication of primary immunodeficiency disorders. When the immune system is deficient or dysfunctional, it may fail to distinguish between self and non-self antigens, leading to the development of autoimmune diseases.

Incorrect choices:

a. Hypertension is a condition characterized by high blood pressure and is not directly related to primary immunodeficiency disorders.

b. Chronic fatigue syndrome is a complex disorder with unknown causes and is not directly related to primary immunodeficiency disorders.

d. Diabetes mellitus is a metabolic disorder caused by insufficient insulin production or insulin resistance and is not directly related to primary immunodeficiency disorders.