Objective: To investigate the hematological abnormalities and their relationship to the disease activity of systemic lupus erythematosus (SLE).
Methods: The clinical data of 236 SLE patients, 29 males and 207 females with the age of confirmed diagnosis of 33.4, were divided into 3 groups: anemia group, with the hemoglobin (Hgb) < 100 g/L, including 2 subgroups, i.e. subgroup of anemia caused by chronic diseases (ACD) and subgroup of hemolytic anemia; low white blood cell group 1 (Group WBC1) with the WBC count < 4.0 x 10(9)/L, white blood cell group 2 (Group WBC2) with the WBC count 3.0 approximately 3.9 x 10(9)/L, immune thrombopenic purpura group (ITP group) with a platelet count < 100 x 10(9)/L, and control group without hematological changes. 72 patients underwent morphologic characterization of their bone marrow. The hematological data and the relationship thereof to the disease activity in different groups were analyzed.
Results: Among the 236 SLE patients 168 (71.18%) had hematological abnormalities and 68 of them (28.82%) without hematological abnormalities. 123 of the 168 patients with hematological abnormalities (52.1%) had anemia, 82 of which (66.7%) had characteristics of anemia caused by chronic diseases, 18 (14.6%) had hemolytic anemia, 8 (6.6%) had hematopoietic abnormalities, and the remaining 15 patients (12%) had anemia caused by unknown reasons. 73 of the 236 SLE patients (30.9%) had a WBC count < 4.0 x 10(9)/L and 57 patients (24.2%) had a platelet count < 100 x 10(9)/L. In the groups with hemolytic anemia, WBC count < 3.0 x 10(9)/L and thrombocytopenia, the complement levels were significant lower, and the levels of C-reactive protein (CRP) and positive anti-dsDNA antibody were significantly higher than those of the controls (all P < 0.05) The rate of positive antiphospholipid antibody of the hemolytic anemic patients and patients with thrombocytopenia were 22.2% and 15.8% respectively, both significantly higher than that of the controls (2.9%, both P < 0.05). 49 of the 72 patients undergoing morphologic characterization of bone marrow had normal cell morphology and a normal appearing bone marrow, 10 had varying degrees of pathologic hematopoietic changes, 2 lacked megakaryocytes, 9 expressed decreased proliferation in all three hematopoietic lineages, and 2 had only a decrease in erythropoiesis.
Conclusion: The reason of the high proportion of anemia among the SLE patients in China may be the higher proportion of anemia caused by ACD in comparison with that abroad. Although SLE patients have lower rates of hemolytic anemia, HA is an important index of SLE disease activity. Thrombocytopenia and a WBC count < 3.0 x 10(9)/L are related to SLE disease activity. Abnormalities of hemopoiesis by bone marrow is one of the reasons of sever hematological changes in part of the SLE patients.