Transfusion safety in the Maghreb region.

The Maghreb region comprises five countries: Algeria Libya, Morocco, Mauritania, and Tunisia. This is a review aiming at providing an update on the situation of transfusion in the five countries. Three countries have developed regulations covering all transfusion-related activities including policy development. All the countries are running blood safety activities using a National Blood Service as the main entity. Except for Mauritania and Lybia, all the blood safety activities are centralized and conducted regularly. The blood safety indicators are globally better compared to those of sub-Saharan Africa. Despite the efforts of the states of the Maghreb region, and the progress made in the field of transfusion in these countries, shortcomings persist and concern virtually all the key elements of a national blood supply system mainly in the quality management system.

HLA class I and class II polymorphisms in Tunisian Berbers.

BACKGROUND: The HLA polymorphism is a powerful genetic tool to study population origins. By analysing allele frequencies and haplotypes in different populations, it is possible to identify ethnic groups and establish the genetic relationships among them. AIM: The Berber (endogenous Tunisians) HLA class I and class II genotypes were analysed and compared with those of Mediterranean and Sub-Saharan African communities using genetic distances, Neighbour-Joining dendrograms, correspondence and haplotype analysis. SUBJECTS AND METHODS: One hundred and five unrelated Berbers were typed for HLA class I (A, B) and class II (DRB1, DQB1) gene alleles using reverse dot-blot hybridization. RESULTS: High frequencies of A*0201 (24.76%), A*3402 (22.38%) and B*44 (32.85%) alleles were recorded for Berbers, the highest recorded for Mediterranean and North African populations. This study shows a close relatedness of Tunisian Berbers to other Tunisians, North Africans and Iberians. CONCLUSION: The apparent relatedness of Tunisian Berbers to present-day (North African) Tunisians, Algerians and Moroccans suggests that the Arab invasion of North Africa (7(th)-11(th) centuries AD) did not significantly impact the genetic makeup of North Africans. Furthermore, Tunisian Berbers appear to be closely related to Iberians (Spaniards and Basques), indicating that the 7(th) century AD gene flow of invaders was low in Iberians and that the main part of their genetic pool came after the Northward Saharan migration, when hyper-arid conditions were established in Sahara (before 6000 BC). Other studied populations belong to the old Mediterranean substratum, which has been present in the area since pre-Neolithic times. This study indicates a higher proportion of Iberian than Arab ancestry in Tunisian Berbers, which is of value in evaluating the evolutionary history of present-day Tunisians. Greeks seem to share genetic HLA features (Chr 6) with Sub-Saharans. The relatedness of Greeks to Sub-Saharans has been confirmed by other studies based on chromosome 7 genetic markers.

The contribution of HLA class I and II alleles and haplotypes to the investigation of the evolutionary history of Tunisians.

The frequencies of HLA class I and class II alleles and haplotypes of 104 healthy unrelated Tunisians were analyzed by high-resolution PCR-reverse dot blot hybridization, and was compared with other Mediterranean and Sub-Saharan Africans using genetic distances measurements, Neighbor-joining dendrograms, correspondence, and extended haplotypes analysis. The most frequent HLA class I A alleles were A*02, A*24, and A*30, while the most frequent B alleles were B*44, followed by B*50, B*51, and B*07. Among HLA class II DRB alleles analyzed, the most frequent were DRB1*0301, DRB1*0701, DRB1*1501, followed by DRB1*1303 and DRB1*0102; for DQB1, they were DQB1*0301 and DQB1*0201. Three-locus haplotype analysis revealed that A*03-B*07-DRB1*1503 and A*02-B*44-DRB1*0402 were the most common HLA class I and II haplotypes in this population. Compared with other communities, our result indicate that Tunisians are very related to North Africans and Western Europeans, particularly Iberians, and that Tunisians, Algerians, and Moroccans are close to Berbers suggesting little genetic contribution of Arabs who populated the area in 7th to 8th century AD. The similarities and differences between Tunisians and neighboring and related communities in HLA genotype distribution provide basic information for further studies of the MHC heterogeneity among Mediterranean and North African countries, and as reference for further anthropological studies.

HLA class II genetic diversity in southern Tunisia and the Mediterranean area.

North Africa is populated by many Arab- and Berber-speaking populations whose genetic history is still poorly understood. In this study, we analyse the HLA-DRB1 and DQB1 molecular diversity in three populations from the south of Tunisia--Berbers from Jerba, Berbers from Matmata and Arabs from Gabes--and we compare them to a large set of populations from the whole Mediterranean region. Among the three populations studied, the Berbers from Jerba are the most peculiar, as they diverge significantly from other North Africans while being genetically highly diversified and close to populations from the Near East. Thus, Jerba may have been a crossing point, in historical times, where colonization from the eastern Mediterranean area left significant genetic traces. By contrast, the populations from Matmata and Gabes are genetically similar to other Arab and Berber-speaking populations from different areas of the Maghrib, despite some peculiar allele and haplotype frequencies. At a larger scale, northwest Africa and southwest Europe are closely related according to these polymorphisms, while the populations from the eastern Mediterranean area are much more differentiated. The close genetic relatedness found for HLA among populations of the western Mediterranean region challenges previous results based on Y chromosome analyses, where the Gibraltar Strait appeared to constitute a main genetic barrier.

HLA genes in Southern Tunisians (Ghannouch area) and their relationship with other Mediterraneans.

South Tunisian HLA gene profile has studied for the first time. HLA-A, -B, -DRB1 and -DQB1 allele frequencies of Ghannouch have been compared with those of neighboring populations, other Mediterraneans and Sub-Saharans. Their relatedness has been tested by genetic distances, Neighbor-Joining dendrograms and correspondence analyses. Our HLA data show that both southern from Ghannouch and northern Tunisians are of a Berber substratum in spite of the successive incursions (particularly, the 7th-8th century A.D. Arab invasion) occurred in Tunisia. It is also the case of other North Africans and Iberians. This present study confirms the relatedness of Greeks to Sub-Saharan populations. This suggests that there was an admixture between the Greeks and Sub-Saharans probably during Pharaonic period or after natural catastrophes (dryness) occurred in Sahara.

Prospective randomised comparison of the COBE spectra version 6 and haemonetics MCS(+) cell separators for hematopoietic progenitor cells leucapheresis in patients with multiple myeloma.

A randomised crossover trial of two separators was undertaken to compare the mononuclear cell, CD34(+) cell and CFU-GM yield, in patients (<61 years) with previously untreated symptomatic multiple myeloma. After first-line therapy, all patients received mobilising chemotherapy (cyclophosphamide 4 g/m(2)) and daily G-CSF. The first leucapheresis was performed on the first day the peripheral blood absolute CD34(+) cell count was > 20 cells/microl. All patients underwent 2 leucaphereses on consecutive days. The patients were randomised to undergo either the first or second leucapheresis using the COBE Spectra. The target duration of the procedure on the COBE Spectra was 2 total blood volumes, and for the Haemonetics MCS(+) it was 20 cycles with four recirculations. Between September 2003 and March 2005, 60 patients were entered in the study. COBE Spectra version 6 processed significantly larger volumes of blood than the Haemonetics MCS(+) (8,845 and 5,680 ml, respectively, P < 0.01). The absolute yield of mononuclear cells (2.1 vs. 1.5 x 10(8)/kg, P = 0.04), CFU-GM (11 vs. 3 x 10(4)/kg, P = 0.01) and CD34(+) cells (3 vs. 1.7 x 10(6)/kg, P = 0.02) were all significantly higher with the COBE Spectra version 6, as were the yields per unit volume of blood processed. In conclusion, our study shows that COBE Spectra Version 6 is faster and has a better yield than the Haemonetics MCS(+), in patients with multiple myeloma.

[HFE gene mutations in Tunisian major beta-Thalassemia and iron overload]. / Mutations du gène HFE chez des beta-thalassémiques majeurs tunisiens et surcharge en fer.

OBJECTIVES: In this study we have determined the allele frequency of HFE mutations H63D and C282Y in a group of Tunisian beta-thalassemia major patients. These two mutations are implicated in hereditary hemochromatosis among Caucasians. In this study we wanted to correlate these mutations with the iron status in major beta-thalassemia patients. DESIGN AND METHODS: Fifty Tunisian major beta-thalassemia were screening for the C282Y and H63D by digestion of polymerase chain reaction products (RFLP). Serum ferritin level was measured by immunoenzymatic microparticular essay. RESULTS: The allele frequency of H63D mutation was 17%. C282Y mutation was not present in our studied patients. No statistically significant difference of serum ferritin level was found between major beta-thalassemia with and without HFE mutations. CONCLUSION: Our results suggest that H63D mutation is so frequent in Tunisian major beta-thalassemia patients than in the general population and that the coinheritance of H63D mutation does not influence the severity of iron overload in these patients.

Detection of serum hemolysins in autoimmune hemolytic anemia.

BACKGROUND: Some patients with autoimmune hemolytic anemia (AIHA) have in their sera autohemolysins able to hemolyze RBCs in vitro by activation of complement. We describe three autohemolysins in patients with AIHA and we study clinical correlations. STUDY DESIGN AND METHODS: Thirty-two patients with AIHA were explored by immuno-hematological investigations (DAT, elution and serum testing). RESULTS: Three autohemolysins were detected in three patients. All of these autoantibodies were likely IgM and reacted in vitro only with enzyme-treated RBCs. Two warm autohemolysins were detected in patients with warm-type AIHA. The first one was active at neutral pH with low title. The second, having a wide thermal amplitude reacting at 22 degrees C and a title of 16, was acid. The hemolysin detected in patient 3 with cold hemagglutinin disease, was active at 4 and 22 degrees C, at acid pH. The thermal optimum was 4 degrees C and the title 64. It was also detected at 37 degrees C with the same title, but only at neutral pH. CONCLUSION: Although these autohemolysins were incomplete, hemolyzing in vitro only enzyme-treated RBCs, they were associated for the three patients with severe hemolysis.

First-line thalidomide-dexamethasone therapy in preparation for autologous stem cell transplantation in young patients (<61 years) with symptomatic multiple myeloma.

Thalidomide-dexamethasone therapy was given in patients (<61 years) with previously untreated symptomatic multiple myeloma. The aim of this study was to assess the efficacy and toxicity of this combination as first-line therapy, and to determine its effect on stem cell collection and engraftment. During first-line therapy, thalidomide and dexamethasone were administered for 75 days (200 mg/day) and 3 months, respectively. The monthly dose of dexamethasone was 20 mg/m2/day for 4 days, with cycles repeated on days 9 to 12 and 17 to 20 on the first and the third month of therapy. After first-line therapy, a collection of peripheral blood stem cells (PBSC) was performed. Between May 2003 and September 2004, 60 patients were included. On an intent-to-treat basis, the overall response (> or =partial response) rate was 74%, including 24% of patients who obtained a complete remission. Grade 3-4 toxicities consisted of infections (12%), deep-vein thrombosis (3%), constipation (5%), and neuropathy (5%). A total of 58 patients (96%) proceeded to PBSC mobilisation and yielded a median number of 8 x 10(6) CD34+ cells/kg. First-line thalidomide-dexamethasone therapy is effective and relatively well tolerated in young patients with symptomatic multiple myeloma. This combination does not affect PBSC mobilisation.

HLA polymorphism in type 1 diabetes Tunisians.

Several studies of the association between HLA and type 1 diabetes have been carried out revealing differences between ethnic groups. Our study, as part of the studies that should be performed about this association in the rest of the word, aims at elucidating the HLA DRB1, DQB1 polymorphism in Tunisian type 1 diabetes. This study includes 43 unrelated type 1 diabetes patients, and their mean age at onset is less than 15 years. Analysis of the frequency of alleles and haplotypes in these subjects, compared to a reference group (n = 101) led to the following results. 1) The Tunisian insulin-dependent diabetics present similarities as well as differences with other ethnic groups (Caucasians, North Africans). 2) The haplotype DRB1*04 DQ*0302 and DRB1*03 DQB1*0201 is positively associated to type 1 diabetes. 3) The heterozygotic genotype DRB1*04 DQB1*0302 / DRB1*03 DQB1*0201 is strongly associated to type 1 diabetes. 4) The haplotypes DRB1*01501 DQB1*0602 and DRB1*11 DQB1*0301 proved to be protective. In addition, the study of the subtypes DRB1*04 showed that alleles DRB1*0405 predispose to type 1 diabetes, whereas the allele DRB1*0403, which is in linkage disequilibrium with the DQB1*0402 in the Tunisian population, has a protective effect.

Gene frequencies of human neutrophil antigens in the Tunisian blood donors and Berbers.

Human neutrophil antigens play an important role in provoking immune neutropenia and transfusion-reactions. The aim of this study was to determine granulocyte-specific antigens on the neutrophil Fc gamma receptor IIIb (Fc gamma RIIIb, CD16b), namely, the HNA-1a(NA1) and HNA-1b(NA2) antigens and their gene frequencies in Tunisian blood donors and Berbers. One hundred and ninety-nine unrelated healthy Tunisian blood donors and Berbers were typed for HNA-1a and HNA-1b(NA1 and NA2), using polymerase chain reaction with sequence-specific primers (PCR-SSP). In 24 granulocyte samples, the HNA-1a and HNA-1b phenotypes was additionally determined by the granulocyte immunofluorescence test (GIFT) and correlated with the genotyping results. A subsequent analysis of the genotyping study showed that, the HNA-1a and HNA-1b gene frequencies observed, were 0.342 and 0.658 for Berbers, and 0.311 and 0.668 for blood donors, respectively. In the genotyping study conducted, it was determined that the HNA-1a and HNA-1b gene frequencies observed in Tunisian blood donors and Berbers are similar to those previously reported in other white populations.

[Autologous transfusion program]. / La transfusion autologue programmee.

The term autologous transfusion describes transfusion of any blood component that was donated by intended recipient. A recipient who serves as his or her own donor receives the safest possible transfusion in that the risks of transfusion-transmitted infection and alloimmunization are eliminated. A preoperative autologous transfusion program provides many benefits to the donor-patient the blood donor center and the hospital transfusion service; requires a good communication between the transfusion physician and the collecting facility and needs a rigorous technical organization of the blood bank to ovoid the human errors of testing and labeling. Underutilizaton of autologous blood programs in our country is possibly related to a lack of awareness on the part of all the contributors.

Rapid high-performance liquid chromatography analysis for the quantitative determination of oleuropein in Olea europaea leaves.

Olea europaea (Oleaceae) leaves of 14 different cultivars have been studied by a new isocratic HPLC method. Qualitative and quantitative determinations of principal compounds were established for each cultivar. Oleuropein concentration was determined for each sampled tree, using coumarin as internal standard. Bid el Haman, Chemlali, Meski, Cailletier, Tanche, a Verdale-Picholine hybrid, and Lucques, in particular, had high oleuropein concentrations and could be useful sources for industrial extractions.

[Association between type 1 diabetes and polymorphism of the CTLA-4 gene in a Tunisian population]. / Etude de l'association entre diabète type 1 et polymorphisme du gène CTLA-4 dans une population tunisienne.

Susceptibility to type 1 diabetes mellitus is strongly associated with particular HLA class II alleles. However, non HLA genetic factors are likely to be required for the development of disease. The candidate genes include the cytotoxic T lymphocyte associated 4 (CTLA-4) located on chromosome 2q33 and designated (IDDM12), which encodes a cell surface negative signal T molecule providing for activation. We investigated CTLA-4 exon 1 dimorphism in 74 type 1 patients and a control group of 48 healthy subjects from Tunisia using two methods PCR (polymerase chain reaction) allele specific and polymerase chain reaction restriction fragment length polymorphism (PCR RFLP). The CTLA-4/G allele was found on 68.9% in type 1 patients as compared to 51.02% in controls (p = 0.002), mostly in homozygous from 43.24% versus 22.45% (p = 0.0058). This results indicate that CTLA-4/G allele was significantly associated with predisposition to type 1 diabetes in our group from Tunisian population.

NA antigen frequencies in the Tunisian population.

The biallelic NA antigen system is of special interest as the NA antigens are frequent targets of neutrophil antibodies, causing alloimmune neonatal neutropenia, blood transfusion reactions, and chronic benign autoimmune neutropenia in infancy. Neutrophils isolated from the peripheral blood of 119 unrelated individuals at the National Blood Center were phenotyped for NA1 and NA2 using a granulocyte immunofluorescence assay. A subsequent analysis of the phenotyping study showed that the NA1 and NA2 antigen frequencies were 0.529 and 0.865 respectively, and that the estimated NA1 and NA2 gene frequencies were 0.313 and 0.632 respectively. In conclusion, it was determined that the Tunisian population is of Caucasian origin. However, to validate this finding, further investigations are necessary.

Contribution of flow cytometry to acute leukemia classification in Tunisia.

The precision of immunological characterization of leukemias was improved by a certain number of technical innovations, particularly hybridoma production and standardization, resulting in monoclonal antibodies and definition of recognised cellular antigens (designated by CD: Cluster of Differentiation). The aim of this work was to determine the immunophenotyping profile of patients with leukemia, by means of a flow cytometric method: 66 blood samples coming from leukemic persons in the Sahel region were studied by flow cytometry, using about thirty monoclonal antibodies all marked with a fluorochrome, in one or two colour systems to assess their distribution according to type (lymphoid B or T / myeloid) and age, and to search for possible co-expressions of markers of different lineages. The marked preponderance of childhood B-ALL in our series is, at least partly, attributable to the age distribution of the Tunisian population. In agreement with studies from other countries, the majority of AML cases occurred among adults. A high proportion of AML cases in our series co-expressed markers of other lineages. Overall, accurate classification of acute leukemias was possible from a simple peripheral blood sample in 62 of 66 cases (93.9%).

Gene frequencies of human platelet antigens in the Tunisian population.

Gene frequencies for the human platelet antigens HPA-1, -3 and -5 in the Tunisian population were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) on 93 volunteer blood donors (78 were tested for HPA-1, 90 for HPA-3 and 93 for HPA-5). This study shows the highest frequencies of the HPA-1b (0.25) and HPA-5b (0.22) yet recorded. These antigens are considered as markers of a high risk of platelet alloimmunisation in other populations, and for this reason particular attention should be paid in the case of pregnancy or blood transfusion in this population. The 9 base pair deletion located in intron 21 of the GPIIb gene associated with HPA-3b determinant is present in this population. No individual showed the polymorphism associated with HPA-1b (T-->G at codon 40 of the GPIIIa).