A DESCRIPTIVE EPIDEMIOLOGICAL STUDY OF HEMATOLOGICAL DISORDERS IN SHOWA UNIVERSITY HOSPITAL

Abstract

As hematological disorders are generally uncommon and the various means of classification have been frequently revised, the epidemiological data of specific hematological disorders is insufficient. We conducted a retrospective study of patients diagnosed with hematological disorders and evaluated the trends in incidence. We enrolled 1824 patients who visited the Department of Hematology, Showa University Hospital between January 2005 and December 2011 (males 828, females 996). The mean patient age was 60.0 (15–98) years. Our results revealed that neoplastic hematological disorders accounted for 56% of the cases and non-neoplastic hematological disorders accounted for 44%. Among the cases of neoplastic hematological disorders, 40% were myeloid neoplasms and 60% were lymphoid neoplasms. The ratio between the incidences of lymphoid and myeloid neoplasms did not significantly vary over the research period spanning 7 years. Among plasma cell neoplasms, the proportion of neoplasms secreting lambda-type chains of immunoglobulins was significantly lower in cases of monoclonal gammopathy of undetermined significance (MGUS) than in others (P=0.04). Thus, lambda-type chain immunoglobulin secretion seems to be a risk factor for progression of MGUS. Among the non-neoplastic hematological disorders, 45.3% were iron deficiency anemia and 17.5% were immunogenic thrombocytopenic purpura. In conclusion, the results of our research provide basic information for studies concerning hematological disorders. Further epidemiological studies with accurate and exhaustive enrollment are needed to clarify the causes of hematological disorders and to evaluate their trends in incidence.