Which test can provide information about immune response in a suspected lymphoma case?

The test that can provide information about immune response in a suspected lymphoma case is the PCR for antigen receptor rearrangements (PARR). This test assesses the clonality of lymphocyte populations by analyzing the rearrangement of immunoglobulin and T-cell receptor genes. In cases of lymphoma, where there is an abnormal proliferation of lymphocytes, PARR can help determine whether the lymphocyte population is clonal, indicative of malignancy. A positive result typically supports a diagnosis of lymphoma, highlighting an abnormal immune response due to the presence of neoplastic lymphoid cells.

Other tests mentioned, while useful in the general evaluation of the patient, don't specifically address the immune response related to lymphoma. Serum biochemistry provides information on organ function and metabolic status but does not reflect immune system activity. A complete blood count offers insights into various cell lines but lacks specificity for determining if a specific lymphocyte population is neoplastic. X-ray imaging is valuable for visualizing anatomical structures, particularly for assessing tumors or lymph node enlargement, but it does not provide direct information about the immune response or lymphocyte clonality in cases of lymphoma.