Which of the following tests is important in screening for hypocomplementemia?

Hypocomplementemia refers to a decreased level of complement proteins in the serum, which can be indicative of various autoimmune conditions, infections, or other pathological states. Specifically, the complement system includes various proteins, among which C3 and C4 are critical components involved in the immune response.

Measuring the levels of C3 and C4 is essential when evaluating a patient for conditions such as Systemic Lupus Erythematosus (SLE) or other autoimmune diseases that may utilize the complement system. When these complement levels are low, it suggests that there may be excessive consumption of complement proteins due to ongoing inflammatory processes or immune reactions.

In contrast, tests such as AST and ALT are primarily markers of liver function and do not provide information about complement levels. Blood culture is used to identify bacterial infections and is not related to complement assessment. Home glucose monitoring is relevant for diabetes management, not for evaluating complement levels.

Thus, the relevant and correct approach for screening hypocomplementemia involves assessing the levels of C3 and C4, making it a critical test in this context.