The nurse is reviewing the diagnostic evaluation for a client with suspected immunodeficiency disorder. Which finding would be consistent with a potential diagnosis of severe combined immunodeficiency (SCID)?

Explanation: The correct answer is c. Serum immunoglobulin levels. A primary immunodeficiency disorder often results in abnormal levels of immunoglobulins (antibodies) in the blood. Measuring serum immunoglobulin levels can help identify potential deficiencies and guide the diagnosis of primary immunodeficiency disorders.

Incorrect choices:

a. Enzyme-linked immunosorbent assay (ELISA) is a test used to detect specific antibodies or antigens in the blood, but it is not specific to diagnosing primary immunodeficiency disorders.

b. A chest X-ray is not a specific test for diagnosing primary immunodeficiency disorders. It is typically used to assess the condition of the lungs and chest organs.

d. A complete blood count (CBC) is a general blood test that may reveal abnormalities in white blood cell count but does not specifically assess immunoglobulin levels.

Explanation: The correct answer is d. Selective IgA deficiency. This disorder is characterized by a lack of immunoglobulin A, which can lead to an increased susceptibility to infections, particularly in the respiratory and gastrointestinal tracts.

Incorrect choices:

a. Selective IgM deficiency is a rare immunodeficiency disorder characterized by a lack of immunoglobulin M (IgM), not IgA.

b. X-linked agammaglobulinemia is a primary immunodeficiency disorder caused by a mutation in the BTK gene, resulting in a deficiency of B cells and immunoglobulins.

c. Common variable immunodeficiency (CVID) is a heterogeneous group of disorders characterized by decreased levels of immunoglobulins, including IgA, IgG, and IgM.