Omar Fahmy

In Vitro and In Vivo Activities of Arachidonic Acid against Schistosoma mansoni and Schistosoma haematobium

ABSTRACT The development of arachidonic acid (ARA) for treatment of schistosomiasis is an entirely novel approach based on a breakthrough discovery in schistosome biology revealing that activation of parasite tegument-bound neutral sphingomyelinase (nSMase) by unsaturated fatty acids, such as ARA, induces exposure of parasite surface membrane antigens to antibody binding and eventual attrition of developing schistosomula and adult worms. Here, we demonstrate that 5 mM ARA leads to irreversible killing of ex vivo 1-, 3-, 4-, 5-, and 6-week-old Schistosoma mansoni and 9-, 10-, and 12-week-old Schistosoma haematobium worms within 3 to 4 h, depending on the parasite age, even when the worms were maintained in up to 50% fetal calf serum. ARA-mediated worm attrition was prevented by nSMase inhibitors, such as CaCl2 and GW4869. Scanning and transmission electron microscopy revealed that ARA-mediated worm killing was associated with spine destruction, membrane blebbing, and disorganization of the apical membrane structure. ARA-mediated S. mansoni and S. haematobium worm attrition was reproduced in vivo in a series of 6 independent experiments using BALB/c or C57BL/6 mice, indicating that ARA in a pure form (Sigma) or included in infant formula (Nestle) consistently led to 40 to 80% decrease in the total worm burden. Arachidonic acid is already marketed for human use in the United States and Canada for proper development of newborns and muscle growth of athletes; thus, ARA has potential as a safe and cost-effective addition to antischistosomal therapy.

Reduced intensity conditioning is effective for hematopoietic SCT in dyskeratosis congenita-related BM failure

BM failure (BMF) is a major and frequent complication of dyskeratosis congenita (DKC). Allogeneic hematopoietic SCT (allo-HSCT) represents the only curative treatment for BMF associated with this condition. Transplant-related morbidity/mortality is common especially after myeloablative conditioning regimens. Herein, we report nine cases of patients with DKC who received an allo-SCT at five different member centers within the Eastern Mediterranean Blood and Marrow Transplantation Registry. Between October 1992 and February 2011, nine DKC patients (male, 7 and female, 2), with a median age at transplantation of 19.1 (4.9–31.1) years, underwent an allo-HSCT from HLA-matched, morphologically normal-related donors (100%). Preparative regimens varied according to different centers, but was reduced intensity conditioning (RIC) in eight patients. Graft source was unstimulated BM in five cases (56%) and G-CSF-mobilized PBSCs in four (44%) cases. The median stem cell dose was 6.79 (2.06–12.4) × 106 cells/kg body weight. GVHD prophylaxis consisted of CsA in all nine cases; MTX or mycophenolate mofetil were added in five (56%) and two (22%) cases, respectively. Anti-thymocyte globulin was administered at various doses and scheduled in four (44%) cases. Median time-to-neutrophil engraftment was 21 (17–27) days. In one case, late graft failure was noted at 10.4 months post allo-HSCT. Only one patient developed grade II acute GVHD (11%). Extensive chronic GVHD was reported in one case, whereas limited chronic GVHD occurred in another four cases. At a median follow-up of 61 (0.8–212) months, seven (78%) patients were still alive and transfusion independent. One patient died of metastatic gastric adenocarcinoma and graft failure was the cause of death in another patient. This study suggests that RIC preparative regimens are successful in inducing hematopoietic cell engraftment in patients with BMF from DKC. Owing to the limited sample size, the use of registry data and heterogeneity of preparative as well as GVHD prophylaxis regimens reported in this series, we are unable to recommend a particular regimen to be considered as the standard for patients with this disease.

Efficacy and mechanism of action of arachidonic acid in the treatment of hamsters infected with Schistosoma mansoni or Schistosoma haematobium

We have recently shown that in vitro and in vivo exposure of Schistosoma mansoni and Schistosoma haematobium to 5-10mM arachidonic acid (ARA) induces parasite surface membrane disintegration and eventual attrition. Here we report on the optimum ARA dose and post-infection treatment time for maximum schistosome demise in hamsters. A series of four experiments for each schistosome species indicated that oral administration of ARA after patency led to a highly significant (P<0.02 to <0.001) reduction in worm burden accompanied by a significant (P<0.05) decrease in worm egg load. ARA-mediated attrition in vivo appeared to be associated with high titres of serum antibodies to tegumental antigens. In support, serum antibodies from patently infected and ARA-treated hamsters readily bound to the surface membrane of ARA-exposed adult worms, as judged by indirect membrane immunofluorescence. More importantly, addition of serum antibodies and peripheral blood mononuclear cells significantly enhanced ARA-mediated adult worm attrition in vitro. These data together show that the schistosomicidal effect of ARA in laboratory animals is enhanced by immune effectors and is highly efficacious and entirely safe.

Hematopoietic Stem Cell Transplantation in the Eastern Mediterranean Region (EMRO) 2008-2009: Report on behalf of the Eastern Mediterranean Bone Marrow Transplantation (EMBMT) Group

BACKGROUND The Eastern Mediterranean Bone Marrow Transplantation (EMBMT) Group has accumulated over 25 years of data and experience in hematopoietic stem cell transplantation (HSCT), most particularly in hemoglobinopathies, severe aplastic anemia (SAA), and inherited metabolic and immune disorders, in addition to hematologic malignancies peculiar to the region and where recent updates in trends in activities are warranted. OBJECTIVES To study trends in HSCT activities in the World Health Organization-Eastern Mediterranean (EM) region surveyed by EMBMT between 2008 and 2009. STUDY DESIGN Retrospective analysis of the survey data, mainly of the cumulative number of transplants, types of transplants (autologous vs. allogeneic), types of conditioning as myeloablative (MAC) vs. reduced intensity conditioning (RIC) and trends in leukemias, hemoglobinopathies, SAA, inherited bone marrow failure syndromes amongst others. RESULTS AND DISCUSSION Fourteen teams from ten Eastern Mediterranean Region Organization (EMRO) countries reported their data (100% return rate) to the EMBMT for the years 2008-2009 with a total of 2608 first HSCT (1286 in 2008; 1322 in 2009). Allogeneic HSCT represented the majority (63%) in both years. The main indications for allogeneic HSCT were acute leukemias (732; 44%), bone marrow failure syndromes (331, 20%), hemoglobinopathies (255; 15%) and immune deficiencies (90; 5%). There was a progressive increase in the proportions of chronic myeloid leukemia (CML) cases transplanted beyond the first chronic phase (3; 7% of all CML cases in 2008 vs 13; 29% in 2009). The main indications for autologous transplants were plasma cell disorders (345; 36%) Hodgkin disease (256; 27%), non-Hodgkin lymphoma (207; 22%) and solid tumors (83; 9%). RIC continued to show a progressive increase over the years (7% in 2007, 11% in 2008 and 13% in 2009), yet remained relatively low compared to contemporary practices in Europe published by EBMT. The vast majority (95%) of allo-HSCT sources were from sibling donors with a continued dominance of peripheral blood (PB) (1076; 63%), while cord blood transplant (CBT) increased to 83 (5% of allo-HSCT), matched unrelated donor (MUD) remained underutilized (1; 0%) and there were no haploidentical transplants reported. Large centers with >50 HSCT/year showed a plateau of the total number of allo-HSCT over the last 5 years that may be related to capacity issues and needs further study. CONCLUSIONS AND RECOMMENDATIONS There is an overall increased rate of HSCT in the EMRO region with a significant increase in utilization of CBT and allogeneic PB-HSCT as a valuable source. However, further research on outcome data and development of regional donor banks (CB and MUD) may help facilitate future planning to satisfy the regional needs and increase collaboration within the group and globally.

Hematopoietic stem cell transplantation in the Eastern Mediterranean Region (EMRO) 2011–2012: A comprehensive report on behalf of the Eastern Mediterranean Blood and Marrow Transplantation group (EMBMT)

OBJECTIVE/BACKGROUND The Eastern Mediterranean Blood and Marrow Transplantation (EMBMT) group has accumulated over 31 years of data and experience in hematopoietic stem cell transplantation (HSCT), particularly in hemoglobinopathies, severe aplastic anemia, inherited metabolic and immune disorders, in addition to a wide array of hematologic malignancies unique to this region. A regional update in current HSCT trends is highly warranted. We studied the trends of HSCT activities in World Health Organization-Eastern Mediterranean (EMRO) region, surveyed by the EMBMT, between 2011 and 2012. METHODS Retrospective analysis of the survey data mainly of cumulative number of transplants, types of transplants (autologous vs. allogeneic), types of conditioning such as myeloablative versus reduced intensity was conducted. Also, trends in leukemias, hemoglobinopathies, severe aplastic anemia, inherited bone marrow failure syndromes, amongst others were analyzed. RESULTS Twenty-one teams from nine EMRO countries reported their data (100% return rate) to the EMBMT for the years 2011-2012, with a total of 3,546 first HSCT (1,670 in 2011; 1,876 in 2012). Allogeneic HSCT (allo-HSCT) represented the majority (62%) in both years. The main indications for allo-HSCT were acute leukemias (988; 46%), bone marrow failure syndromes (421, 20%), hemoglobinopathies (242; 11%), and immune deficiencies (157; 7%). There was a progressive increase in the proportions of chronic myeloid leukemia cases transplanted beyond first chronic phase (37 [7%] of all chronic myeloid leukemia cases in 2011 vs. 39 [29%] in 2012). The main indications for autologous transplants were multiple myeloma/plasma cell disorders (510; 39%), Hodgkin lymphoma (311; 24%), non-Hodgkin lymphoma (259; 20%), and solid tumors (163; 12%). Reduced intensity conditioning continued to show a progressive decrease over years (9.5% in 2011 vs. 7.9% in 2012), yet remained relatively low compared with contemporary practices in Europe published by EBMT. The vast majority (91%) of allo-HSCT source was from sibling donors with continued dominance of peripheral blood (64%) followed by bone marrow (33%).While umbilical cord blood transplants increased to 4% of allo-HSCT, matched unrelated donor remained underutilized and there was no haplo-identical transplant reported. Large centers with >50 HSCT/year, showed a continued increase in the total number of allo-HSCT over the past 2years that may be related to capacity building issues and require further studies. CONCLUSION There is a discernable increase of HSCT rate in the EMRO region with a significant expansion in utilization of cord blood transplants and allogeneic peripheral blood-HSCT as a valuable source. However, further research of outcome data and the development of regional donor banks (cord blood and matched unrelated donors) may help to facilitate future planning to satisfy the escalating regional needs and augment collaboration within the EMBMT and globally.

Narrowing the gap for hematopoietic stem cell transplantation in the East-Mediterranean/African region: comparison with global HSCT indications and trends

Hematopoietic Stem Cell Transplantation (HSCT) activity was evaluated in the African (AFR)/EMRO region and compared to the global activity for the years 2006–2013. Data were obtained from 1570 teams in the 6 WHO continental regions. Of these, 29 (1.85%) of all teams were active in 12 of the 68 AFR/EMRO countries. They reported 2.331 (3.3%) of the worldwide 71.036 HSCT, and a transplant rate of 32.8 (TR; HSCT/10 million inhabitants; worldwide 128.5). This reflects still the lowest regional TR despite an increase of 90% since 2006. HSCT activity in AFR/EMRO countries was characterized by a higher use of allogeneic compared to autologous HSCT, an almost exclusive use of family donors, including haploidentical family donors. These findings contrast with the prevalence of autologous over allogeneic HSCT, and a higher frequency of unrelated HSCT in other parts of the world. Of note, the increase by 200% in HSCT for hemoglobinopathies from 2006 to 2013 (72 per year) in the AFR/EMRO region. This reflects the specific role of HSCT for these disease categories with high prevalence and incidence in the AFR/EMRO region. This report provides information for the competent authorities to foster adequate infrastructure. It urges transplant organization to optimize their cooperation.