A POPULATION-BASED REGISTRY ON PARAPROTEINEMIA IN THE NETHERLANDS

Patients with monoclonal gammopathies comprise a heterogenous group. T he few studies on incidence and follow-up are single-centre-based and may reflect referral bias. To avoid this, all patients (n = 1275) in m idwestern Netherlands with a newly discovered paraproteinaemia in 1991 , 1992 and 1993 were included in a population-based registry and divid ed into four major diagnostic groups: multiple myeloma and plasmacytom a (n = 230, 18%), other haematological diseases (n = 141, 11%), parapr otein-related internal diseases (n = 191, 15%) and monoclonal gammopat hy of undetermined significance (MGUS, n = 713, 56%). To avoid a possi bly erroneous diagnosis, patients who were classified as having MGUS b ut who did not undergo confirmatory bone marrow examination were inclu ded in a separate group 'provisional MGUS' (n = 524, 41%), whereas pat ients who did were classified as having 'definite MGUS' (n = 189, 15%) . The 'provisional MGUS' patients were relatively older and had more o ften a poor performance status, but differences between this and the ' definite MGUS' group were otherwise small. Patients complaining of gen eral malaise more often had a full work-up of their paraproteinaemia. Bone pain, hypercalcaemia, high total protein, and high ESR occurred p redominantly in the myeloma group, whereas fever or infection was less often seen in these patients. This registry of patients with paraprot einaemias provided valuable data related to all different diseases ass ociated with paraproteinaemia.