Donor-derived hairy cell leukemia

Reduced-intensity stem cell allografting for PNH patients in the eculizumab era: The Mexican experience

Background Paroxysmal nocturnal haemoglobinuria (PNH) presents as two major entities: the classical form, predominantly haemolytic and a secondary type with marrow failure and resultant aplastic anaemia (AA-PNH). Currently, the treatment of choice of the haemolytic variant is eculizumab; however, the most frequent form of PNH in México is AA-PNH. Patients and methods Six consecutive AA-PNH patients with HLA-identical siblings were allografted in two institutions in México, employing a reduced-intensity conditioning regimen for stem cell transplantation (RIST) conducted on an outpatient basis. Results Median age of the patients was 37 years (range 25-48). The patients were given a median of 5.4 × 10(6)/kg allogeneic CD34(+) cells, using 1-3 apheresis procedures. Median time to achieve above 0.5 × 10(9)/l granulocytes was 21 days, whereas median time to achieve above 20 × 10(9)/l platelets was 17 days. Five patients are alive for 330-3150 days (median 1437) after the allograft. The 3150-day overall survival is 83.3%, whereas median survival has not been reached, being above 3150 days. Conclusion We have shown that hypoplastic PNH patients can be allografted safely using RIST and that the long-term results are adequate, the cost-benefit ratio of this treatment being reasonable. Additional studies are needed to confirm the usefulness of RIST in the treatment of AA-PNH.

Secondary malignancies after allogeneic hematopoietic stem cell transplantation using reduced-intensity conditioning and outpatient conduction

BACKGROUND

Patients given allogeneic hematopoietic stem cell transplants (HSCT) may develop secondary malignant neoplasms (SMN). Several variables have been identified but there are no data about the incidence of this complication in individuals given HSCT using reduced-intensity conditioning (RIC) methods.

OBJECTIVE

Define the incidence of SMN in patients given HSCT using a RIC preparative regimen conducted on an outpatient basis.

MATERIALS AND METHODS

Patients given HSCT in two institutions between October 1998 and 2012 were analyzed. To appraise the SMN appearance, those patients dead were also regarded as censored at that moment, as well as those lost to follow up and those alive at the closing of the study. 95% Confidence intervals (CI) for the survival or failure estimate were calculated with the Greenwood's method.

RESULTS

A total of 416 allografted patients with a Karnofsky performance index of 100% were included in the study. All patients received peripheral blood stem cells allografts. The conditioning regimen was delivered as an outpatient procedure in all individuals. No patient was given radiotherapy nor antithymocyte globulin during the conditioning. Three hundred and sixty five patients (88%) were never admitted to the hospital, whereas 12% were admitted because of grade III-IV acute graft versus host disease (aGVHD), fever, or mucositis. Median survival time was 15.7 months. Survival at 6 months (95% CI): 66.4% (61.5-70.8%), at 12 months: 53.3% (48.1-58.1%), at 60 months: 30.6% (30.5-41.5%). Eight patients with a SMN were identified in the group of 416 allografted patients, SMN rates (95% CI) were: one year post graft: 1.9% (0.7-4.9%), 5 years: 3.8% (1.6-9.2%), 10 years: 6.8% (2.6-17.7%) and 13 years post-graft: 20.2% (5.5-59.2%), the cumulative probability of SMN being 6.8 at 10 years. Since the number of expected cases in the general population is 0.62, the ratio of observed to expected cases is 12.9 (P < 0.001). This figure means that the risk of developing a malignant neoplasm in allografted individuals using our method is 12.9 times higher than that in the general population. There were three non-Hodgkin's lymphomas, two M2 acute myelogenous leukemias, one hairy cell leukemia, one tongue epidermoid carcinoma, and one breast carcinoma.

CONCLUSIONS

We have found a low incidence of SMN in this group of Mexican patients allografted with the Mexican RIC method. Possible explanations for this difference are discussed, focusing on the RIC preparative regimen.