Inhibition of hematopoiesis by a plasma factor in a case of aplastic anemia associated with systemic lupus erythematosus

Systemic Lupus Erythematosus (SLE) may be associated with inhibition of hematopoiesis mediated by antibodies, T-cells or both. A 41-year-old woman with a five-year history of SLE treated with prednisone was admitted to Cabrini Medical Center in New York. The patient complained of fever, chills, arthralgias, general malaise, weakness and dyspnea on exertion, and showed malar rash, pallor, and a systolic ejection murmur along the left sternal border. Admission work up included a CBC with evidence of moderate pancytopenia, a normal EKG, and a normal chest X-ray. The patient's anemia was symptomatic and required a transfusion of packed red blood cells (PRBC's). Bone marrow biopsy and aspiration revealed an aplastic marrow with few hypoplastic islands of hematopoietic elements. The patient was treated with plasmapheresis, achieving immediate progress towards recovery. Bone marrow culture studies (erythroid BFU-E, and myeloid CFU-GM) were done by incubating various titers of the patient's acute phase plasma with normal bone marrow cells. This was done to determine if the patient's plasma contained any hematopoietic inhibitory activity, as has been reported in other cases. Our experiments demonstrated marked inhibition of erymathropoiesis and myelopoiesis in vitro, when various titers of the patient's plasma were included in the culture media. Control plasma produced no inhibition. These studies support the hypothesis that a circulating antibody which inhibits hematopoiesis may be produced in SLE patients with aplastic anemia, and be responsible for it

Appearance of adherent cells suppressive to erythropoiesis during an early stage of Plasmodium berghei infection in mice.

We examined the effect of adherent cells from bone marrow or spleen of mice infected with Plasmodium berghei on dyserythropoiesis. Significant reduction in number of erythroid progenitors (erythroid colony-forming units: CFU-E and erythroid burst-forming units: BFU-E) was observed in bone marrow as early as 1 day after P. berghei infection. When adherent cells were removed from bone marrow or spleen cells of infected mice, the number of CFU-E and BFU-E was clearly increased. Furthermore, addition of adherent cells from infected mice to nonadherent cells from normal mice inhibited erythroid colony formation significantly in a dose-dependent manner. These results suggest that the adherent cells obtained from bone marrow or spleen of mice in the early stage of P. berghei-infection have a suppressive effect on erythropoiesis.