Other prognostic factors: plasma cell labelling index

Plasma cell labelling index (PCLI) is a technique that determines how quickly the myeloma cells are proliferating and growing. It involves incubating myeloma cell samples taken from the bone marrow with a radioactive compound which is taken up when cells divide.

A high labelling index means that there is a more rapid accumulation of myeloma cells and is generally a poor prognostic indicator. During early disease, myeloma cells proliferate slowly but with disease progression, the labelling index may increase significantly. Some studies have shown that a high PCLI may predict a shorter time to progression and reduced survival.

PCLI provides useful prognostic information but as the test is not widely available, it is not performed routinely.