Autoimmune pancytopenia. Lymphocyte inhibition of autologous but not allogenic bone marrow growth in vitro

Laparoscopic splenectomy for Evans syndrome

Evans syndrome is a rare, chronic, sometimes fatal immunologic disorder defined as Coombs' positive hemolytic anemia and immune thrombocytopenia without an underlying etiology. This syndrome has a variable clinical course, and the benefit of splenectomy is unknown. This report reviews the clinical outcome of laparoscopic splenectomy for Evans syndrome. A retrospective review was conducted of patients undergoing laparoscopic splenectomy for autoimmune hemolytic anemia and concomitant immune thrombocytopenic purpura at the Cleveland Clinic Foundation from August 1995 through August 2001. Data were collected in a prospective database and included demographic characteristics of the patients, surgical indications, operative details, and postoperative follow-up information. Five patients underwent laparoscopic splenectomy for Evans syndrome. At mean follow-up of 18 months (range, 1-31) after laparoscopic splenectomy, two patients had normal platelet counts (>100,000/microL) and required no further medical therapy. Two patients did not respond to laparoscopic splenectomy and are still undergoing medical therapy. One patient initially responded to laparoscopic splenectomy but became thrombocytopenic at 18 months and required further medical therapy. After 2 months of further medical treatment, this patient is currently (at month 10) in remission. Laparoscopic splenectomy for Evans syndrome is safe and technically feasible. The clinical outcome of splenectomy for patients with Evans syndrome is unpredictable. This select cohort of patients requires extensive long-term follow-up to determine the merits of splenectomy.

Current considerations of the etiology of aplastic anemia

Aplastic anemia is a disorder characterized by marrow aplasia and pancytopenia. The pathogenetic mechanisms that lead to bone marrow aplasia have been intensively studied. Data obtained from these studies suggest that aplastic anemia is a heterogeneous disorder with regards to pathogenesis. Bone marrow aplasia may result from a number of abnormalities including qualitative or quantitative abnormalities of hematopoietic stem cells, abnormal interaction between bone marrow accessory cells (lymphocytes and macrophages) and hematopoietic stem cells, cytotoxic humoral inhibitors of hematopoiesis, and abnormalities of the bone marrow microenvironment. A number of new therapeutic options have improved the survival of patients with aplastic anemia. Allogeneic bone marrow transplantation has actually resulted in the cure of patients. Unfortunately, only a minority of patients have a suitable bone marrow donor and alternate modes of therapy have been sought. Encouraging results have been reported from several centers concerning the use of antilymphocyte serum in patients with aplastic anemia. Certainty of the ultimate long-term benefit of this type of immunosuppressive therapy is not possible until careful, randomized, prospective studies of its use are completed.

Lymphocytotoxic T lymphocytes in a patient with B-chronic lymphocytic leukemia and pure red cell aplasia

The peripheral blood T cells of a hypertransfused patient with B-chronic lymphocytic leukemia and pure red cell aplasic were found to exhibit unusual spontaneous cytotoxic activity in vitro. The patient's E-rosette positive cells were cytotoxic for K562 (cultured human erythroleukemia cells) and allogeneic B and T lymphocytes freshly isolated from the peripheral blood of normal and CLL donors. They failed to kill autologous B cells, erythroid progenitors present in allogeneic bone marrow, and a number of cultured human tumor cells (Malme, CAKI) even after prolonged (36 h) co-culture. Peripheral blood T cells isolated from normal controls, other CLL patients, and hypertransfused individuals (n = 13) did not exhibit spontaneous lymphocytotoxic activity. Circulating cytotoxic T cells having the ability to kill freshly isolated allogeneic lymphocytes have, heretofore, not been reported in humans. Our findings suggest that among this patient's peripheral blood T cells, there exists a subpopulation of lymphocytotoxic cells that closely resemble cytotoxic T cells generated in vitro after priming with allogeneic target cells. Although the lymphocytotoxic cells could have been induced in this patient by previous HLA-mismatched transfusions, it is possible they may have arisen spontaneously and underly the patient's erythroblastopenic state.

Cell mediated inhibition of erythropoiesis and megaloblastic anemia in T-cell chronic lymphocytic leukemia

A patient with T-cell chronic lymphocytic leukemia presented with severe megaloblastic anemia with normal serum folic acid and cobalamin concentrations. BFU-E could not be cultured from the patient's peripheral blood unless T-lymphocytes were removed by E-rosette formation. Inhibitory activity by the patient's T-cells was restricted to autologous BFU-E. After cyclic chemotherapy the anemia and megaloblastic changes resolved, peripheral blood BFU-E could be cultured from unfractionated peripheral blood and the T-cell inhibitory activity could no longer be demonstrated. The anemia in this patient is probably due to the neoplastic expansion of a suppressor T-lymphocyte population.

Congenital dyserythropoietic anaemia type II (CDA-II): chromosomal banding studies and adherent cell effects on erythroid colony (CFU-E) and burst (BFU-E) formation

Bone marrow CFU-E and BFU-E from a patient with CDA-II formed erythroid colonies and bursts which contained multinucleated erythroblasts in vitro. Adherent cell depletion of the patient's marrow increased CFU-E derived colonies six-fold (98 +/- 17 v. 640 +/- 15 per 10(5) marrow cells plated) and co-culture of CDA-II marrow adherent cells with CSA-II adherent cell depleted marrow significantly suppressed erythroid colony formation. Similar adherent cell suppression of the patient's BFU-E also occurred. Adherent cell depletion of normal marrow did not increase CFU-E derived colony formation (488 +/- 63 v. 495 +/- 108) and decreased BFU-E derived burst formation. Addition of normal adherent cells to normal marrow increased erythroid colony and burst formation. Karyotype and chromosomal banding studies of the patient's multinucleated cells did not show chromosomal inversions, deletions or translocations.