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A patient with myelofibrosis with myeloid metaplasia displaying the V617F mutation of the JAK2 gene was given an allogeneic stem cell transplantation using a reduced-intensity conditioning regimen. The patient engrafted, and as he became a chimera, the expression of the V617F mutation of the JAK2 gene decreased progressively until its disappearance. Accordingly, the concept of "molecular remission" of the myelofibrosis with myeloid metaplasia could be entertained and added to the categories of response to treatment which have been recently described., ((c) 2006 Wiley-Liss, Inc.)

We studied the effectiveness of a fludarabine/cyclophosphamide-based conditioning regimen without anti-thymocyte globulin in 23 aplastic anemia patients who had no response to previous conventional pharmacologic treatment. Patients received oral busulphan 4 mg/kg/day/2 days, IV cyclophosphamide 350 mg/m(2)/day/3 days, and fludarabine 30 mg/m(2)/day/3 days. For GVHD prophylaxis, patients received MTX 5 mg/m(2) days +1, +3, +6, and +11 and oral cyclosporin A (CyA) 5 mg/kg/day, starting on day -1. Peripheral blood stem cell products were used with a median dose of 5.5 x 10(6) CD34(+)/kg. The patients were followed for an average of 25 months. By a median of day +11, an ANC > 0.5 x 10(9)/L was reached; and by day +12, the platelet count had reached >20,000 x 10(9)/L. Acute grade I-II GVHD occurred in 4 patients, whereas limited chronic GVHD presented in 6 cases. Twenty-one patients (91.3%) achieved engraftment. Two patients failed to engraft, and 4 developed late rejection; 2 of these individuals died, 2 have survived with high transfusion requirements, whereas 2 received a second peripheral blood stem cell infusion and achieved sustained engraftment. Currently 21 (91%) of the 23 patients are alive, whereas 19 of 21 (90%) remain in complete remission. The average cost was about USD 15,000 for this kind of reduced-intensity allotransplant. Reduced-intensity stem cell transplantation represents an affordable alternative to traditional more cytotoxic conditioning for severe aplastic anemia (SAA) patients. Long-term effects however, remain to be evaluated.

Over a 36-month period, 46 consecutive Mexican mestizos with a clinical marker associated with a primary hypercoagulable state were prospectively assessed by searching for the sticky platelet syndrome (SPS), the activated protein C resistance (aPCR) phenotype, coagulation protein C activity and antigen, coagulation protein S, antithrombin III, plasminogen, tissue-type plasminogen activator activity, plasminogen activator inhibitor activity, plasminogen activator inhibitor type 1, IgG and IgM isotypes of antiphospholipid antibodies, homocysteine levels, the factor V gene Leiden, Cambridge, Hong Kong, and Liverpool mutations, the 677 C-->T mutation in the 5,10-methylenetetrahydrofolatereductase (MTHFR), and the G20210A polymorphism in the 3'-untranslated region of the prothrombin gene. Of the 46 consecutive patients prospectively accrued in the study, only 12 (26%) were males, the median age being 38 years (range 10-63 years). In only four individuals (8%) could we not record any abnormality. In 5/42 patients with abnormal results (12%), a single abnormality was recorded, whereas in the remaining 37, two to five co-existing abnormalities were identified. We found 22 (48%) patients with the SPS, 11 (24%) with the aPCR phenotype, 5 (11%) with the factor V Leiden mutation, 7 (15%) with the prothrombin gene mutation, 29 (63%) with the MTHFR gene mutation, 11 (24%) with the factor V HR2 haplotype, 11 (24%) with antiphospholipid antibodies, 4 (9%) with PS deficiency, 6 (13%) with PC deficiency, one with the FV Hong Kong mutation, and one with AT-III deficiency. The results are consonant with the idea that most cases of thrombophilia in Mexico are multifactorial.

The prevalence of cytomegalovirus (CMV) reactivation and disease after non-myeloablative stem cell transplantation is largely unknown. Using fludarabine combined with alemtuzumab or antithymocyte globulin in the conditioning regimen, some authors have found increased prevalences of CMV disease, whereas other authors using different schedules have observed decreased prevalences. In a group of 17 individuals allografted using the Mexican conditioning regimen, which employs fludarabine, cyclophosphamide, and busulfan, we assessed CMV reactivation, morbidity, and mortality. Before transplant, IgG anti-CMV antibodies were found in 11 patients and in 10 donors; in 8 cases, both donor and patient had IgG anti-CMV antibodies. In only one case (6%) was CMV mRNA identified 30 days after the allograft during grade IV acute graft-versus-host disease. CMV reactivation, disease, and mortality were very low using our non-myeloablative stem cell transplantation schedule, which has been shown to be useful for allografting with minimal toxicity and reduced costs., (Copyright 2004 Wiley-Liss, Inc.)

Using nonmyeloablative, immunosuppressive, fludarabine (FLU)-based conditioning regimens, we have performed allogeneic peripheral blood stem cell transplants in 26 patients (8 with chronic myelogenous leukemia, 6 with acute myelogenous leukemia, 10 with acute lymphoblastic leukemia, 1 with myelodysplasia, and 1 with thalassemia major). Conditioning consisted of FLU/busulphan/cyclophosphamide/cyclosporin-A (CyA)/methotrexate, or FLU/melphalan/CyA/methotrexate. The median granulocyte recovery time to 0.5 x 10(9)/l was 11 days, whereas the median platelet recovery time to 20 x 10(9)/l was 12 days. Twelve patients did not need red blood cell transfusions, and 8 did not need platelet transfusions. In 21 individuals (81%), the procedure could be completed fully on an outpatient basis. Follow-up times range between 30 and 600 days: one patient failed to engraft and recovered endogenous hemopoiesis; six out of 26 patients developed acute graft-versus-host disease (GVHD) whereas 7/22 developed chronic GVHD. Twelve patients (46%) have died, nine of them with a relapsing disease and three with GVHD; median post-transplant survival (SV) was 300 days, whereas the 12-month SV was 42%. The 100-day mortality was 3.8% and the transplant-related mortality was 11.5%. This procedure is substantially less costly than its counterpart, using in-hospital myeloablative conditioning regimens, and it may represent another approach in the management of patients requiring an allogeneic stem cell transplant., (Copyright 2001 Wiley-Liss, Inc.)

We have shown that in Mexican mestizo patients with clinical features of primary thrombophilia, 39% have activated protein C resistance phenotype, 5% protein C deficiency, and 2% protein S deficiency. In the present study, in a group of 37 thrombophilic Mexicans and 50 normal controls, we assessed the factor V G1691A (Leiden), the prothrombin G20210A, and the methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphisms. Four patients were found to be heterozygous for factor V Leiden, 5 heterozygous for the prothrombin 20210, 16 heterozygous, and 6 homozygous for the MTHFR 677. There were four individuals with co-segregation of alleles: two heterozygotes for the factor V Leiden/prothrombin 20210, one heterozygote for prothrombin 20210/MTHFR 677, and one heterozygote for prothrombin 20210/homozygote for MTHFR 677. For factor V Leiden, prothrombin 20210, and MTHFR 677 mutations, the allele frequencies were respectively 1% (+/-0.2%, alpha = 0.05), <1% and 51% (+/-5%, alpha = 0.05), with calculated relative risks for thrombosis of 5.94 (P = 0.08), >7.66 (P < 0.05), and 0.44 (P NS), respectively. In Mexican mestizo thrombophilic patients, the low prevalence of the factor V Leiden mutation (10.8%) and the high prevalence of the prothrombin 20210 mutation (13.5%) contrast with those identified in Caucasian thrombophilic patients (21% and 6%, respectively; P < 0.01). On the other hand, the high prevalence of the MTHFR 677 mutation gene both in normal controls (78%) and thrombophilic patients (61%) does not support a role of this mutation in the thrombogenesis of Mexican mestizo patients.

The results of the treatment of 43 patients with acute promyelocytic leukemia (PML) are reported: 27 were treated initially with all-trans-retinoic acid (ATRA), whereas 16 were treated with conventional chemotherapy. All patients received myelosuppressive chemotherapy after the initial treatment. Respectively, the complete remission rate was 92% and 37% (P < 0.01), the 5-day mortality rate was 0% and 44% (P < 0.001), and the 28-day mortality rate was 4% and 44% (P < 0.001). The median disease-free survival was 12 and 1 months (P < 0.01), whereas the 12-month disease-free survival was 50% and 13% (P < 0.01) and the 36-month disease-free survival was 41% and 9% (P < 0.01). Thirteen of the patients treated with ATRA were given the treatment fully as outpatients. ATRA given as initial therapy decreased significantly early mortality in promyelocytic leukemia patients; because some promyelocytic leukemia patients given ATRA as initial therapy can be treated as outpatients, the costs of this treatment modality may be diminished., (Copyright 1999 Wiley-Liss, Inc.)

A group of 102 Mexican Mestizo patients with appropriate clinical features suggestive of primary thrombophilia was prospectively studied. Thirty-nine percent of them had activated protein C resistance, but only four patients displayed the factor V Leiden mutation. Five percent of the individuals were found to be protein C deficient, whereas 2% had protein S deficiency. No cases of abnormalities in antithrombin III, plasminogen, tissue-type plasminogen activator or plasminogen activator inhibitor were found. The low prevalence of the activated protein C resistance genotype, probably stemming from the genetic admixture of the Mexican Mestizo group is noteworthy.

We have prospectively performed peripheral blood stem cell autotransplants in six patients with hematological malignancies on an entirely outpatient basis. Patients were conditioned with high-dose melphalan and received a median of 4.2 x 10(8)/kg non-cryopreserved, non-purged mononuclear cells, containing a median of 3.9 x 10(6)/kg CD34 + cells. The median time to achieve > 500 granulocytes/microl was 21 days, with a range of 16 to 40, whereas the median time to achieve > 20,000 platelets/microl was 38 days, with a range of 21 to 48. Only three patients were transfused with platelets whereas packed red blood cells were transfused in two. All patients survived 60 days after the autograft and three are alive at 450, 690, and 1,950 days after the autotransplant. One patient was given an allogeneic bone marrow transplant when relapsing after the autotransplant. One patient had to be admitted to the hospital on day +10 because of fever. A median of 6,500.00 USD per patient was calculated as the total cost of each outpatient autotransplant. Since outpatient autologous transplants with non-frozen PBSC are feasible, restrictions to PBSC autotransplant programs may be overcome and costs may be diminished.

Considering that the prevalence of some hematologic malignancies may have a geographic distribution that could be related with its etiology, a group of 2,387 patients with acute leukemia (1,968 adults and 419 children) was studied along a 5-year period in six different locations within México. Twenty-seven patients (16 males and 11 females) with hairy cell leukemia (HCL) were identified. The adjusted overall proportion of HCL, after excluding data from centers reporting only adults, was 1.12% of all leukemia cases; this figure is lower than that reported in the United States or England. The proportion of adult leukemic patients with HCL was significantly higher in the northern region of the country-where there are more people devoted to farming and agricultural activities-as compared with the central or southeastern regions (3.07 vs. 1.03% vs. 0%; P < 0.05); possible explanations for these differences are briefly discussed.

We studied 21 filgrastim (G-CSF)-mobilized peripheral blood stem cells (PBSC) apheresis products obtained from seven patients, and stored at 4 degrees C for periods of up to 96 hr prior to their reinfusion, to rescue high-dose chemotherapy. The apheresis products contained a median of 106 x 10(8)/L mononuclear cells (MNC), 14.6% of them displaying the CD34 antigen; the viability was over 90% in all samples studied at 24, 48, and 72 hr after harvesting. These PBSC were successfully used to rescue high-dose chemotherapy; patients received a median of 4.8 x 10(8)/Kg MNC; the median time to achieve > 500 granulocytes was 14 days (range 11-26) and the median time to achieve > 20,000 platelets was 20 days (range 11-40). Since autologous transplants with nonfrozen PBSC are feasible and less costly than those using frozen PBSC, restrictions to PBSC autotransplant programs may be overcome and costs may be diminished.

Six patients with chronic refractory autoimmune thrombocytopenic purpura (ATP) were treated with five doses of autologous red blood cells (RBCs) opsonized ex vivo with anti-RhO-(D) IgG. Increases in platelet counts were observed in all cases; complete responses requiring no further treatment--for periods of 8-72 months--were recorded in four patients, three of them splenectomized. The cost of the procedure was significantly lower than other "Fc receptor (FcR) blockade" treatments.

The prognosis and long-term results of a group of 57 acute megakaryoblastic leukaemia (M7-AML) patients was analysed from a multicentre perspective. Ages ranged from 4 to 83 years, median 49 years; 30 were males and 27 were females. The median follow-up time was 7 months, range 1-24 months. Early exits occurred in 12 cases, their median age being 71 years. Forty-five patients were treated with combined aggressive chemotherapy (CT) (n = 26) or low-dose cytarabine (LD-AraC) (n = 19). The following results were obtained with combined CT or AraC, respectively. Complete remission (CR) rates were 73% and 84%, 12-month survival (SV) were 37% and 26%, 24-month SV were 12% and 11%, median SV 10 and 4 months, and relapse rates (RR) were 68% and 94%. These differences were not statistically significant. Irrespective of the treatment modality, the results were better for children (n = 10) than for adults (n = 35): RR rates were 90% and 74%, median SV: 7 and 5 months, 12-month SV: 40% and 22%, 24-month SV; 30% and 9%, and RR: 78% and 81%, respectively; these differences also were not statistically significant. In addition, a literature review of 42 patients from 18 previous reports is presented, including seven cases treated with allogeneic bone marrow transplantation (BMT). The best results were obtained with BMT: 12 and 24 month SV was 86% and the RR was 0%. On the above-mentioned basis, we feel that children and young adults with M7-AML should be offered BMT. In patients over 60 years old or not eligible for aggressive chemotherapy or BMT, an interesting possibility would be the use of LD-AraC which allows a high CR rate, followed by a classical consolidation regimen in order to prevent early relapses.

Increased thrombogenesis observed in systemic lupus erythematosus (SLE) is derived from multiple mechanisms, including: Enhanced coagulation factor VIII:VWf activity, lupus anticoagulants, anti-phospholipid antibodies, acquired deficiencies of natural anti-thrombotic mechanisms (protein C, protein S, anti-thrombin III), and impaired fibrinolytic mechanisms. We studied the fibrinolytic mechanisms of 18 patients with systemic lupus erythematosus, selected carefully to avoid other possible causes of abnormalities in the fibrinolytic activity. Despite the fact that the euglobulin lysis time in steady state was normal in all instances, disturbances in the tissue plasminogen activator/plasminogen activator inhibitor (TPA/PAI) system were found in all SLE patients: TPA activity was undetectable in all cases, whereas it was above 0.4 IU/ml in a control group. In 72 percent of patients, the undetectable TPA activity was correlated with abnormally high PAI activity; PAI levels were normal in all members of the control group, their mean value being 0.74 versus 8.63 IU/ml for SLE patients (P less than .01). Coagulation protein C deficiency was found in 3 patients (17%). Even though within normal range, fibrinogen levels were significantly higher in SLE than in normal controls (219 versus 192 mg/dl, P less than .01) and plasminogen levels were significantly higher in SLE than in controls (117 versus 78.2%, P less than .01). Cross-linked fibrin derivatives (D-D dimers) were negative in all patients with SLE. Sixty-eight percent of SLE patients had high levels of antiphospholipid antibodies, but no correlation with the disturbances of the TPA/PAI system was found. It is concluded that most patients with SLE display severe abnormalities in the TPA/PAI anti-thrombotic system and that these abnormalities may be related to the lupus thrombophilia, apparently multifactorial in its origin.

A mouse monoclonal antibody (R1-3) raised against a human plasmacytoma xenograft and reactive with human plasma cells is described. The antibody reacts with a subset of plasma cells and lymphocytes, but is nonreactive with granulocytes, normoblasts, thymus, spleen or T lymphocytes. Flow cytometer double labelling experiments showed that approximately 50% of R1-3 positive bone marrow cells expressed surface immunoglobulin, but no R1-3 positive cells also expressed B1 or Leu 4. In a myeloma patient the R1-3 reactive cells were found to have a higher rate of DNA proliferation and were aneuploid as determined by flow cytometry. The R1-3 antigen is expressed on late B lymphocytes and early plasma cells.

Lymphocyte subsets were enumerated in a group of 31 patients with aplastic anemia. Abnormal numbers of immunoregulatory T-cells were found in some patients: 26% of them showed a reversed helper/suppressor ratio. Seven of 18 patients showed significantly decreased proliferation in response to PWM; this hyporesponsiveness was present in 75% of patients with a reversed helper/suppressor ratio and in 10% of those with a normal helper/suppressor ratio (R = 0.66, P = 0.008). Eight of 18 patients showed suppressor activity over PWM-induced allogeneic cell proliferation. This suppressive activity did not correlate with T-cell phenotype. Of the patients with a low number of T-cells, 73% had responded to treatment, whereas of those patients with a normal number of T-cells, 26% had responded (P = 0.016). The results are consistent with abnormal immune response in selected patients with aplastic anemia, and suggest a possible influence of T-cells on disease process.

Acute megakaryoblastic leukaemia remains an uncommonly recognized disorder, usually identified by electron microscopy or with monoclonal antibodies. Using two monoclonal antibodies (HP1-1D identifying glycoprotein IIB/IIIA and W1-23 identifying von Willebrand factor) we have studied during a 12 month period all cases of acute leukaemia with FABL2,M1 or undifferentiated morphology presenting in our cooperative group 'Grupo de Hematólogos de Puebla' in México. Six of 21 FAB L2, M1 or undifferentiated leukaemias were classified immunologically as megakaryoblastic. Five of these patients had myelofibrosis and two had normal platelet counts but abnormal platelet aggregation function. All six patients were treated with low-dose cytosine arabinoside (10 mg/m2) administered subcutaneously, twice daily in 21 d courses). Haematologic response was achieved in five cases while the sixth died before completing one course. Three patients relapsed within the first month after completing the chemotherapy and died. Two patients remain in remission 11 and 15 months after initial treatment. It is our impression that the prevalence of acute megakaryoblastic leukaemia has been under-estimated, and that low-dose cytosine arabinoside treatment may be of value in its management.