Free Kappa (Free Light Chain)

The free kappa freelite chains serum test measures the concentration of free kappa light chains in the bloodstream.

• The free kappa freelite chains serum test is typically done to diagnose and monitor plasma cell disorders, such as multiple myeloma, amyloidosis, light chain deposition disease, and monoclonal gammopathy of undetermined significance (MGUS).

• It is also useful in detecting and measuring minimal residual disease (MRD) after treatment of plasma cell disorders.

The free kappa freelite chains serum test may be recommended in the following situations:

• When a patient has signs or symptoms of a plasma cell disorder, such as bone pain, fatigue, kidney problems, anemia, or infections.

• When a patient has abnormal results from other tests that suggest the presence of a monoclonal protein or an abnormal immunoglobulin.

• When a patient has a confirmed diagnosis of a plasma cell disorder and needs to be monitored for response to treatment or disease progression.

• Patients who have or are at risk of developing a plasma cell disorder should discuss the test with their healthcare provider.

A positive result in the free kappa freelite chains serum test may suggest the presence of a plasma cell disorder, such as multiple myeloma or amyloidosis. However, the results should be interpreted in conjunction with other clinical and laboratory findings, as some benign conditions or medications can also affect the levels and ratio of free light chains.

The test involves a blood draw, where a healthcare professional will collect a small sample of blood from a vein, usually in the arm. The procedure is quick and painless.

Patients do not need any special preparation before the test. However, they should inform their healthcare provider if they are taking any medications or supplements that may interfere with the test results.

Additional tests that may be ordered along with the free kappa freelite chains serum test include:

• Free lambda freelite chains serum test: To measure the levels of free lambda light chains and calculate the ratio of free kappa to free lambda light chains.

• Serum protein electrophoresis: To separate and measure the different types of proteins in the blood, including immunoglobulins.

• Urine protein electrophoresis: To separate and measure the different types of proteins in the urine, including free light chains.

• Immunofixation electrophoresis: To identify and characterize the specific type of monoclonal protein or immunoglobulin in the blood or urine.

• Bone marrow biopsy: To examine the cells and tissues in the bone marrow and look for abnormal plasma cells.

• Kappa FLC test

• Serum FLC assay

• Free light chain assay

Plasma cell disorders are a group of diseases that involve the abnormal proliferation (overgrowth) of plasma cells, a type of white blood cell that produces antibodies (immunoglobulins). These disorders are characterized by the uncontrolled growth and accumulation of plasma cells in the bone marrow, which can lead to various complications. The three main types of plasma cell disorders are:

1. Multiple Myeloma: Multiple myeloma is a cancer of plasma cells, and it is the most common and serious plasma cell disorder. In this condition, malignant plasma cells accumulate in the bone marrow, forming tumors that can cause bone damage and interfere with the normal production of blood cells. Multiple myeloma can also lead to the production of abnormal proteins (M proteins) that may be detected in the blood or urine.

2. Monoclonal Gammopathy of Undetermined Significance (MGUS): MGUS is a condition where there is an abnormal proliferation of plasma cells, leading to the production of monoclonal proteins. While MGUS itself is generally asymptomatic and does not cause significant health problems, it is considered a precursor condition to multiple myeloma or other plasma cell disorders. Regular monitoring is often recommended for individuals with MGUS to detect any progression.

3. Plasmacytoma: Plasmacytomas are localized collections or tumors of abnormal plasma cells that can occur in bones (solitary bone plasmacytoma) or soft tissues (extramedullary plasmacytoma). Unlike multiple myeloma, plasmacytomas are often isolated and do not involve widespread bone marrow or systemic complications. However, they can progress to multiple myeloma in some cases.