Danazol therapy for aplastic anemia refractory to immunosuppressive therapy.

Although there are anecdotal reports of the efficacy of danazol in the treatment of aplastic anemia (AA), there has been no systematic study to clarify its efficacy and toxicity. Therefore, we assessed the efficacy of danazol for treatment of patients with AA refractory to immunosuppressive therapy (IST) and those who relapsed after IST, in a prospective clinical trial. Sixteen patients (12 males and four females; six severe cases and 10 moderate cases) were treated with 300 mg of danazol daily for 12 weeks. All patients completed the treatment period without occurrence of severe toxicity. Three female patients achieved partial remission, whereas only two of the 12 male patients did so. None of the responders had shown a response to previous IST or an increase in the percentage of paroxysmal nocturnal hemoglobinuria (PNH)-type cells which are known to be a marker for a good response to IST. These findings indicate that danazol is effective for a subset of AA patients, and particularly for female patients with AA refractory to IST.

Roles of DRB1 *1501 and DRB1 *1502 in the pathogenesis of aplastic anemia.

OBJECTIVE: Although a number of reports have documented a significantly increased incidence of HLA-DR15 in aplastic anemia (AA), the exact role of HLA-DR15 in the immune mechanisms of AA remains unclear. We herein clarify the difference between DRB1( *)1501 and DRB1( *)1502, the two DRB1 alleles that determine the presentation of HLA-DR15, in the pathophysiology of AA. MATERIALS AND METHODS: We investigated the relationships of the patients( *) HLA-DRB1 allele with both the presence of a small population of CD55(-)CD59(-) (PNH-type) blood cells and the response to antithymocyte globulin (ATG) plus cyclosporin (CsA) therapy in 140 Japanese AA patients. RESULTS: Of the 30 different DRB1 alleles, only DRB1( *)1501 (33.6% vs 12.8%, p(c) < 0.01) and DRB1( *)1502 (43.6% vs 24.4%, p(c) < 0.01) displayed significantly higher frequencies among the AA patients than among a control. AA patients possessing HLA-DR15 tended to be old, and especially, the frequency of DRB1( *)1502 in patients 40 years of age and older (52.4%) was markedly higher than that in those younger than 40 years old (16.2%, p(c) < 0.01). Only DRB1( *)1501 was significantly associated with the presence of a small population of PNH-type cells and it also showed a good response to ATG plus CsA therapy in a univariate analysis. A multivariate analysis showed only the presence of a small population of PNH-type cells to be a significant factor associated with a good response to the immunosuppressive therapy (p < 0.01). CONCLUSIONS: Although both DRB1( *)1501 and DRB1( *)1502 contribute to the development of AA, the methods of contribution differ between the two alleles.

Cyclosporine therapy for acquired aplastic anemia: predictive factors for the response and long-term prognosis.

Although cyclosporine (CsA) is a key drug in the treatment of acquired aplastic anemia (AA), the role of single-agent therapy with CsA remains unclear. To determine the efficacy of CsA in the treatment of AA, we treated 38 AA patients with CsA alone and followed up the patients for 6 months to 16 years. Twenty patients (53%) achieved either a partial or complete remission within 1 year of starting CsA therapy. Thirteen (81%) of 16 patients who showed an increase in the reticulocyte count of >20 x 10(9)/L within 2 months achieved remission, whereas the response rate was only 32% in patients who failed to show such an increase in the reticulocyte count. The actuarial overall survival and failure-free survival rates at 5 years were 91% and 37%, respectively. These data indicate that CsA alone can achieve a sustained remission in approximately 40% of AA patients, with a low probability of inducing secondary clonal diseases. Given its low toxicity and because the effectiveness of CsA can be judged within 2 months of therapy, CsA may be the first drug of choice at outpatient clinics for AA patients not requiring transfusions.

Genital herpes due to acyclovir-sensitive herpes simplex virus caused secondary and recurrent herpetic whitlows due to thymidine kinase-deficient/temperature-sensitive virus.

Herpes simplex virus (HSV)-2 caused a genital ulcer in a 40-year-old allogenic stem cell recipient, and a secondary herpetic whitlow appeared during 2 months of acyclovir (ACV) therapy. Both genital ulcer, and whitlow were cured 3 months later, but 6 months after recovery the whitlow alone recurred. DNA of the genital, first, and recurrent whitlow isolates showed similar endonuclease digestion fragment profiles. The genital virus was ACV-sensitive, and the two whitlow isolates were ACV-resistant/thymidine kinase (TK)-deficient. The TK gene of the whitlow isolates had the same frame shift from the 274th amino acid and termination at the 347th amino acid due to the deletion of a cytosine at the 819th nucleotide. Because the temperature of the thumb is 33/34 degrees C or lower, the temperature sensitivity of the isolates were compared, and both whitlow isolates were significantly more temperature-sensitive (ts) at 39 degrees C than the genital isolate. The two whitlow isolates showed cutaneous pathogenicity in mouse ear pinna but not midflank, while the genital isolate was pathogenic at both sites, suggesting that temperature adaptation was an important element of pathogenicity in the whitlow. The virus populations of isolates of the genital, and first whitlow were examined by 31, and 82 clones, respectively, and the clones from genital, and whitlow isolates were ACV-sensitive, and -resistant, respectively, showing their homogeneity. The acyclovir-sensitive genital lesion had spread as a TK-deficient/ts herpetic whitlow during ACV treatment, and an apparently TK-deficient virus adapted to the local temperature might have caused the whitlow recurrence.

Specific antibodies to moesin, a membrane-cytoskeleton linker protein, are frequently detected in patients with acquired aplastic anemia.

To identify novel autoantibodies in acquired aplastic anemia (AA), we screened the sera of patients with AA possessing small populations of paroxysmal nocturnal hemoglobinuria (PNH)-type cells for the presence of antibodies (Abs) which recognize proteins derived from a leukemia cell line, UT-7. Immunoblotting using proteins derived from lysates or culture supernatants of UT-7 cells revealed the presence of IgG Abs specific to an 80-kDa protein. Peptide mass fingerprinting identified this 80-kDa protein as moesin. Enzyme-linked immunosorbent assay (ELISA) using recombinant moesin showed high titers of antimoesin Abs in 25 (37%) of 67 patients with AA. Moesin was secreted from several myeloid leukemia cell lines other than UT-7, such as OUN-1 and K562, as an exosomal protein. The presence of antimoesin Abs was significantly correlated with the presence of PNH-type cells and antidiazepam-binding inhibitor-related protein-1 (DRS-1) Abs. Patients with AA that did not show any of these 3 markers tended to respond poorly to immunosuppressive therapy. These findings suggest that a B-cell response to moesin, possibly derived from hematopoietic cells, frequently occurs in patients with AA and that detection of antimoesin Abs in combination with other markers may be useful in diagnosing immune pathophysiology in patients with AA.

Graft rejection and hyperacute graft-versus-host disease in stem cell transplantation from non-inherited maternal-antigen-complementary HLA-mismatched siblings.

Human leukocyte antigen (HLA)-mismatched stem cell transplantation from non-inherited maternal antigen (NIMA)-complementary donors is known to produce stable engraftment without inducing severe graft-versus-host disease (GVHD). We treated two patients with acute myeloid leukemia (AML) and one patient with severe aplastic anemia (SAA) with HLA-mismatched stem cell transplantation (SCT) from NIMA-complementary donors (NIMA-mismatched SCT). The presence of donor and recipient-derived blood cells in the peripheral blood of recipient (donor microchimerism) and donor was documented respectively by amplifying NIMA-derived DNA in two of the three patients. Graft rejection occurred in the SAA patient who was conditioned with a fludarabine-based regimen. Grade III and grade IV acute GVHD developed in patients with AML on day 8 and day 11 respectively, and became a direct cause of death in one patient. The findings suggest that intensive conditioning and immunosuppression after stem cell transplantation are needed in NIMA-mismatched SCT even if donor and recipient microchimerisms is detectable in the donor and recipient before SCT.

Minor population of CD55-CD59- blood cells predicts response to immunosuppressive therapy and prognosis in patients with aplastic anemia.

We investigated the clinical significance of a minor population of paroxysmal nocturnal hemoglobinuria (PNH)-type blood cells in patients with acquired aplastic anemia (AA). We quantified CD55-CD59- granulocytes and red blood cells (RBCs) in peripheral blood from 122 patients with recently diagnosed AA and correlated numbers of PNH-type cells and responses to immunosuppressive therapy (IST). Flow cytometry detected 0.005% to 23.1% of GPI-AP- cells in 68% of patients with AA. Sixty-eight of 83 (91%) patients with an increased proportion of PNH-type cells (PNH+) responded to antithymocyte globulin (ATG) + cyclosporin (CsA) therapy, whereas 18 of 39 (48%) without such an increase (PNH-) responded. Failure-free survival rates were significantly higher (64%) among patients with PNH+ than patients with PNH- (12%) at 5 years, although overall survival rates were comparable between the groups. Numbers of PNH-type and normal-type cells increased in parallel among most patients with PNH+ who responded to IST, suggesting that these cells are equally sensitive to immune attack. These results indicate that a minor population of PNH-type cells represents a reliable marker of a positive IST response and a favorable prognosis among patients with AA. Furthermore, immune attack against hematopoietic stem cells that allows PNH clonal expansion might occur only at the onset of AA.

Epstein-Barr virus (EBV)-associated post-transplantation lymphoproliferative disorder simultaneously affecting both B and T cells after allogeneic bone marrow transplantation.

Post-transplantation lymphoproliferative disorder (PTLD) is usually an aberrant proliferation of EBV-infected B cells. We report the case of a 31-year-old man with severe aplastic anemia who suffered PTLD 42 days post-BMT from an unrelated donor. At the onset of PTLD, peripheral blood lymphocytes were comprised of 40% CD20(+) cells, 3% CD4(+) cells, and 56% CD8(+) cells. A highly sensitive in situ hybridization (ISH) method was used to detect EBV-encoded small non-polyadenylated RNA 1 (EBER-1) in 33.9% of sorted CD20(+) cells, 4.4% of CD4(+) cells, and 1.4% of CD8(+) cells. Each T-cell fraction contained less than 0.034% of contaminated EBV-infected B cells. Clonal proliferation of both B and T cells was demonstrated by Southern blotting. The patient did not respond to donor leukocyte infusion and died due to deterioration of PTLD. At autopsy, examination of multiple organs revealed B-cell (rather than T-cell) infiltration. This case clearly indicates that EBV can simultaneously infect B and T cells and can induce clonal proliferation of both lymphocyte subsets in severely immunocompromised patients.

Clinical significance of a minor population of paroxysmal nocturnal hemoglobinuria-type cells in bone marrow failure syndrome.

A minor population of blood cells deficient of glycosylphosphatidylinositol (GPI)-anchored membrane proteins is often detected in patients with aplastic anemia (AA), though the clinical significance of such paroxysmal nocturnal hemoglobinuria (PNH)-type cells remains unclear. To clarify this issue, we studied 164 patients with myelodysplastic syndrome (MDS) for the presence of CD55(-)CD59(-) granulocytes and red blood cells using sensitive flow cytometry. Among the different subgroups of MDS, a significant increase (ie, at least 0.003%) of PNH-type cells was detected in 21 of 119 patients with refractory anemia (RA); this frequency (17.6%) of RA patients with increased PNH-type cells (PNH(+) patients) was much lower than what we previously reported (52.0%) for AA patients. PNH(+) RA patients had distinct clinical features compared with RA patients without increased PNH-type cells (PNH(-) patients), such as less pronounced morphologic abnormality of blood cells, more severe thrombocytopenia, lower rates of karyotypic abnormality (4.8% vs 32.8%) and of progression to acute leukemia (0% vs 6.2%), higher probability of response to cyclosporine therapy (77.8% vs 0%), and higher incidence of HLA-DR15 (90.5% vs 18.5%). These data indicate that the presence of a minor population of PNH-type cells suggests a benign type of bone marrow failure, probably caused by an immunologic mechanism. To choose an appropriate therapy, peripheral blood should be tested using sensitive flow cytometry for the presence of PNH-type cells in all patients with bone marrow failure before treatment.

Polyclonal hematopoiesis maintained in patients with bone marrow failure harboring a minor population of paroxysmal nocturnal hemoglobinuria-type cells.

Although a minor population of paroxysmal nocturnal hemoglobinuria (PNH)-type blood cells is often detected in patients with aplastic anemia (AA) and refractory anemia (RA), the significance of such cells in the pathophysiology of bone marrow (BM) failure remains obscure. We therefore examined clonality in peripheral blood granulocytes from 118 female patients with AA or myelodysplastic syndrome using the X chromosome inactivation pattern. Clonality, defined as a clonal population accounting for 35% or more of total granulocytes, was confirmed in 22 of 68 (32.4%) AA patients, in 13 of 44 (29.5%) RA patients, in all 4 RA with excess blasts (RAEB) patients, and in 4 patients with PNH. When the frequency of patients with granulocyte clonality was compared with respect to the presence of increased PNH-type cells, the frequency was significantly lower in AA patients with (PNH+; 21.2%) than without (PNH-; 42.9%) increased numbers of PNH-type cells (P =.049). Clonality was absent in granulocytes from the 15 PNH+ RA patients but present in 13 of 29 (44.8%) PNH- RA patients (P =.0013). The absence of clonality in AA and RA patients before treatment was strongly associated with positive response to immunosuppressive therapy (without clonality, 74.4%; with clonality, 33.3%; P =.0031) in all patients as well as in PNH+ patients (without clonality, 96.2%; with clonality, 66.6%, P =.026). These results suggest that AA and RA with a minor population of PNH-type cells are benign types of BM failure with immune pathophysiology that have little relationship to clonal disorders such as RAEB or acute myeloid leukemia.

Diazepam-binding inhibitor-related protein 1: a candidate autoantigen in acquired aplastic anemia patients harboring a minor population of paroxysmal nocturnal hemoglobinuria-type cells.

To identify candidate antigens in aplastic anemia (AA), we screened proteins derived from a leukemia cell line with serum of an AA patient and identified diazepam-binding inhibitor-related protein 1 (DRS-1). Enzyme-linked immunosorbent assay (ELISA) revealed high titers of anti-DRS-1 antibodies (DRS-1 Abs) in 27 (38.0%) of 71 AA patients displaying increased paroxysmal nocturnal hemoglobinuria (PNH)-type cells (PNH(+)), 2 (6.3%) of 32 PNH(-) AA patients, 5 (38.5%) of 13 PNH(+) myelodysplastic syndrome (MDS) patients, and none of 42 PNH(-) MDS patients. DRS-1 gene was abundantly expressed in myeloid leukemia cell lines and in CD34(+) cells derived from healthy individuals. Stimulation of T cells from an AA patient displaying high DRS-1 Abs with a putative CD4(+) T-cell epitope (amino acid residues [aa's] 191-204) presented by HLA-DR15, which overlapped with a hot spot (aa's 173-198) of DRS-1 Ab epitopes, gave rise to T cells cytotoxic for L cells (murine fibroblasts) that were transfected with DRB1*1501 and DRS-1. Enzyme-linked immunospot assay demonstrated increased frequency of T-cell precursors specific to the DRS-1 peptide in other HLA-DR15(+) AA patients displaying high DRS-1 Ab titers. These findings indicate that DRS-1 may serve as an autoantigen eliciting immune attack against hematopoietic stem cells in a subset of AA patients characterized by increased PNH-type cells.