[Difficulties of the care of public antigen alloimmunization]. / Difficultés de la prise en charge de l'allo-immunisation anti-public.

Alloimmunization against high-frequency erythrocyte antigens is a problematic situation in terms of laboratory diagnosis, transfusion and obstetrical management. We report the case of a pregnant woman alloimmunized against public Ag. We detail the difficulties of alloantibody (Ab) identification and transfusion management of the deliveries. A 29-year-old pregnant woman was hospitalized in gynecology and obstetrics departments at 36 weeks of gestation for assessment of hydrops fetalis. Antibody identification test revealed the presence of a pan-reactive antibody. Investigations realized in CNRGS (Paris) concluded in anti-GE2+anti-RH3+autoantibody. The red cell phenotype was GE: -2,3. A therapeutic interruption of the pregnancy was indicated. A program of autologous transfusion was organized with withdrawal of 2 units of blood. The 2nd pregnancy took place normally. Before delivery, an autologous blood reserve consisting of 2 red cell packs and 2 fresh frozen plasma was withdrawn and transfused after delivery. The management of anti-public alloimmunization poses several problems. The first one is of diagnostic nature with, on the one hand, the difficulty of Ab identification by the available red cell panels and, on the other hand, the possible presence of alloantibodies of transfusional or obstetric interest masked by anti-public Ab. The second is represented by transfusional care of these patients. In the absence of a national reserve of frozen rare blood, the autologous transfusion remains the only alternative. However, it can answer only a limited number of indications and only in case of moderate blood loss.

[Motivation and sociology of blood donors in Tunisia: reality and perspectives]. / Motivation et sociologie des donneurs de sang en Tunisie : réalités et perspectives.

In Tunisia, blood donation is voluntary, anonymous and non-remunerated. The aim of the study is to analyze donor motivation and sociology in the regional center of transfusion of Sfax. Between 14 May 2007 and 23 June 2007, a total of 903 Tunisian blood donors filled a questionnaire. Among the donors, 81.8% were men and have a mean age of 34.2 years and the majority of them have an age between 18 and 29 years. The middle social class was majority (77.8%) as well as the liberal profession (65.1%). Primary and secondary education were dominant (79.3%). Among the blood donors, 41.6% were new donors and 28.6% had a history of a single donation, 50.3% were voluntary and 49.7% replacement donors. The reasons motivating the voluntary donation were solidarity (69.9%), religion (21.2%), health benefit (3.6%) and insurance for the family (5.2%). The replacement donors refuse the voluntary donation for not obvious reasons (51%), lack of availability (13.3%), difficulties of accessibility of the sites of collection (7.6%), phobia of the blood and the stings (4.02%) or by refusal of blood donation (1.79%). The information and the raising awareness of the replacement donors could change in a near future their attitudes to become voluntary and regular donors. The implication of donor associations in the organization of the collections and the promotion of the blood donation would be of considerable contribution.

[Red blood cell immunization in haemoglobinopathie: about 84 cases]. / Immunisation anti-érythrocytaire dans les hémoglobinopathies : à propos de 84 cas.

AIMS: To estimate the rate of red cell immunization in hemoglobinopathies. PATIENTS AND METHODS: Prospective study (1990-2009) about 84 patients: 44 homozygous sickle cell anemia, one heterozygous sickle cell anemia S/C, 30 thalassemia and nine sickle cell anemia-thalassemia. The mean age was 10.13 years (extremes: 1-45). The red cell units transfused were ABORH1 compatible, then RH-KELL phenotyped after 2006 and phenocompatible after alloimmunisation. The cross-match was realized using indirect antiglobuline test. Irregular red cell antibody screening was realized before every transfusional episode and the direct antiglobuline test was done when there was a poor transfusional efficiency. RESULTS: The number of red blood cells units transfused was 3545 (42.2/patient). The number of red cell antibody screening and the number of direct antiglobulin test were respectively 1474 (17.5/patient) and 272 (3.2/patient). Twenty-seven antibodies were identified (32.1%): 14 alloantibodies (16.6%, 16.6% in sickle cell disease, 16.6% in thalassemia, P=1), 16 antoantibodies (19.04%, 11.1% in sickle cell disease, 33.3% in thalassemia, P=0.018). There were three cases of association of allo- and autoantibodies. The most frequent alloantibodies were anti-RH3 and anti-KEL1 and were developed after transfusion of standard red cell units. There was no significant relation, neither between sex and risk of immunization, nor between the number of red cell units transfused and alloimmunization. On the other hand, there was a significant relation between autoimmunization and the number of red cell units transfused in thalassemia (P<0.001). CONCLUSION: This study proves the interest of using RH-KELL red cell units compatible in patients with hemoglobinopathies in order to reduce alloimmunisation rates.

[Irregular antibody testing during pregnancy in Tunisia: clinical study of 5369 women]. / Recherche des agglutinines irrégulières en milieu obstétrical en Tunisie: étude à propos de 5369 femmes.

PURPOSE OF THE STUDY: To evaluate the prevalence of alloimmunization in women followed in an obstetrical environment in Tunisia, to identify the specificities of antibodies found and to determine factors that could influence the appearance of this immunization. METHODS: We proceeded to a retrospective analysis of search for irregular antibodies in women followed up in obstetrical environment over nine consecutive years (2000-2008). The panel was officially defined and produced by the Regional Centre for Blood Transfusion in Sfax (Tunisia). RESULTS: Overall 5369 women benefited from 6575 antibody testing (average: 1.22; extremes: 1-14). The results were positive for 278 women (5.17 %), allowing to identify 216 antibodies or associations of antibodies. Among identified antibodies, those immune were found in 198 women. The rate of alloimmunization was 3.68 % (198/5369). The majority of the antibodies found was anti-Rh1, isolated or associated with another antibody, in 84.3 % of the total immunized women. The immunization of women according to the number of gestations showed a significant increasing rate ranging from 2.34 % for a first gestation to 5.27 % for four gestations or more. In addition, a significant difference was also noted between the rate of immunization in women who had received anti-Rh1 immunoglobulin and those who had not. CONCLUSION: Anti-Rh1 immunization is the most frequent in the population of studied women. This could denote of an insufficiency in pregnancies follow-up and immunoprophylaxis protocols.

[Hemogram reference values: study of 1000 healthy adults from Sfax]. / Valeurs de référence de l'hémogramme: étude chez 1000 adultes sains de la region de Sfax.

The aims of this study is to determine the hemogram reference values in a population of healthy adults of the region of Sfax, to compare our results with those from the literature, to estimate the age and sex variations in the blood count. The hemogram parameters were analyzed in 1000 blood donors. Hemogram was performed using Coulter ACT10's analyser. The differential leukocyte count was manually performed. The means of erythrocyte count, hemoglobin, haematocrit and red cell indices were significantly lower in women than in men. There was a significant variation in the red blood cell count, hemoglobin and haematocrit with age. There is also sex and age differences of the leukocyte count. The neutrophil and eiosinophil counts were higher in women than in men. The lymphocytes decreased with age in both sexes. The platelet count was significantly higher in women than in men. These results can be applied only to our local population of adults. The definition of reference values for the Tunisian population requires a study on a more diversified population, including more important number of individuals from various regions of the country.

[Sero-epidemiological study of West Nile virus circulation in human in Tunisia]. / Étude séroépidémiologique de la circulation du virus West Nile chez l'Homme en Tunisie.

West Nile virus (WNV) is an arbovirus classified into the family of Flaviviridae, genus Flavivirus. It is responsible for neurological diseases that occurred frequently as outbreaks and considered as an emerging infection in different regions of the world. In Tunisia, two outbreaks of meningoencephalitis due to this virus occurred, in 1997 and 2003. The virus circulation is studied only in Sahel, region affected by the two epidemics. The aim of this study is to determine if WNV is present in other regions of the country where, up to now, no data are available. A total of 1,854 sera collected from healthy patients were investigated by ELISA to detect specific IgG, during January to December 2007. Patients included are from three governorates: Kairouan, Bizerte, and Sfax. The governorate of Sfax (center of Tunisia) was affected by the two outbreaks, whereas only two cases were observed previously at Kairouan and no cases at Bizerte. Specific IgG were detected in 12.5% of studied population. This seroprevalence varied largely between the three governorates studied. Globally, three regions with different endemicity were described: high endemicity at Kairouan (27.7%), moderate at Sfax (7.5%), and low at Bizerte (0.7%). At Kairouan, the seroprevalence is significantly higher in individuals aged over 40. Our results suggest that WNV circulates in Tunisia; it has a high risk not only in regions affected by previous outbreaks but throughout the country. An active surveillance should be instituted in the country. It must target individuals, and animals, which can be vectors or reservoirs for the virus.

Diagnostic value of an enzyme-linked immunosorbent assay using the recombinant CT694 species-specific protein of Chlamydia trachomatis.

AIM: To study the performance of the CT694 protein in relation to the microimmunofluorescence (MIF) and the pELISA tests for the serodiagnosis of Chlamydia trachomatis infections. METHODS AND RESULTS: The CT694 protein was produced as recombinant protein and was used as antigen in ELISA test for the detection of C. trachomatis IgG antibodies. The performance of the developed ELISA test was compared to the MIF test at two cut-off values of 16 and 64, and to the specific pELISA test using a panel of 342 sera. These sera were from children MIF C. trachomatis and Chlamydophila pneumoniae negative, patients MIF C. pneumoniae positive, patients MIF C. trachomatis positive, patients suspected to have chlamydial infections diagnosed by the Cobas Amplicor test, healthy blood donors and prostitutes. Our results indicate that the developed ELISA test has performed better compared with the MIF and the pELISA tests. The highest performance was obtained when comparing the developed ELISA test in relation to the pELISA, yielding an overall sensitivity and specificity of 85% and 87% respectively. CONCLUSIONS: The CT694 ELISA showed the best performance when compared to the species-specific pELISA test and may be used for the serodiagnosis of C. trachomatis infections. SIGNIFICANCE AND IMPACT OF THE STUDY: The CT694 ELISA test responds to the criteria of both sensitivity and specificity according to the MIF and pELISA tests and may be used for serodiagnosis of C. trachomatis infections.

Comparison of hepatitis A seroprevalence in blood donors in South Tunisia between 2000 and 2007.

The aim of the study was to assess hepatitis A virus (HAV) seroprevalence in blood donors from South Tunisia in two periods 2000 and 2007. Serum samples collected from 376 blood donors in each period aged 18 to 30 years from different regions of South Tunisia were analysed for anti-HAV IgG. The global seroprevalence of HAV infection was 85.9% in 2007 as compared with 94.9% in 2000. The seroprevalence in the 18-20 years age group was 91.9% in 2000 vs 80.6% in 2007, and increased to 99% in 2000 and 92% in 2007 in the subjects over 26. Taking account of geographic area, the HAV seroprevalence in Sfax city decreased from 88.9% in 2000 to 62.7% in 2007 (p < 0.001), but it is still approximatively the same in rural areas (98.4% and 96%) and in the governorates of South Tunisia (97.6% and 99.2%). In conclusion, the number of adults in the city of Sfax which are not immunized against HAV is increasing. Thus, adolescents and young adults are at risk to develop symptomatic and potentially severe hepatitis A.

[Relevance of plasma exchange in the treatment of myasthenia gravis: study of 11 cases]. / Apport des échanges plasmatiques dans le traitement de la myasthénie: étude de 11 cas.

BACKGROUND: The use of plasma exchange (PE) constituted an advance in the treatment of myasthenia. The objective of our study was to determine the relevance of PE in the treatment of myasthenia and to study the different complications which can be observed during PE. PATIENTS AND METHODS: We studied retrospectively 11 patients who have generalized myasthenia and underwent PE. We used an intermittent flow cell separator and we performed PE three times a week. Biological assessment was performed before and after PE for all patients. The exchange volume was calculated according to the patient weight, gender and the value of hematocrit. RESULTS: Our series included six women and five men. The mean age at onset of the disease was 41.4+/-14.1 years (range: 18 to 68). Indication of PE was myasthenia crisis (eight cases), resistance to classic treatment (two cases) and exacerbation after thymectomy (one case). An improvement was observed rapidly in five cases and delayed in three cases. The remaining three patients did not improve. The most frequent side effects of PE were hypotension (four cases), heart arrhythmia (two cases) and hypoglycemia (one case). Three patients dead in the seven days after the first PE. CONCLUSION: PE represents an interesting tool to treat severe forms of myasthenia and improve prognosis. High incidence of complications in our series can be explained by the initial disease severity, the used method of PE, the existence of associated illness, and a long stay in intensive care unit.

[Prevalence of anti-CMV antibodies in blood donors in the Sfax region (value in blood transfusion)]. / Prévalence des anticorps anti-CMV chez les donneurs de sang de la région de Sfax (intérêt en transfusion sanguine).

Detection of anti-CMV antibodies was carried out in sera of healthy blood donors, divided into groups of 20 according to age and sex. Sera were tested for anti-CMV by an ELISA test (Enzygnost anti-CMV/IgG-Behring). Among 280 sera, 272 were positive for IgG to CMV (97.14%). The prevalence of those antibodies was high in all age stratum (95-100%) but was higher in women than in men (98.57% versus 95.71%). The titre of IgG to CMV was superior to 12 Ul/ml in 56.43% of CMV positive donors. So, the leucocyte removal is the only alternative for the prevention of post-transfusional CMV infection. The high percentage of donors with anti-CMV antibodies level more than to 12 Ul/ml allow to consider the use of plasmapheresis for preparing specific immunoglobulins to CMV.

[Prevalence of hemoglobin abnormalities in Kebili (Tunisian South)]. / Prévalence des anomalies de l'hémoglobine à Kebili (sud Tunisien).

BACKGROUND: Hemoglobin abnormalities constitute a public health problem in many countries in the world. In Tunisia, these disorders were thought to affect only the North-western population. However, the existence of hemoglobinosis concentration in Kebily in south Tunisia has been suggested by previous work. In order to estimate their frequencies, we performed a screening of hemoglobin abnormalities in the North-Kebili region, to establish a prevention program of the homozygous forms. METHODS: This screening concerned all 1st and 2nd grade primary school pupils in North Kebily. After a questionnaire, a blood sample was drawn from every child. Hemogram, sickling test, and hemoglobin electrophoresis at alkaline pH were performed for all children. Hemoglobin electrophoresis at acid pH and a specific hemoglobin A2 titration were performed for some children. RESULTS: The study concerned 1,400 children, aged between 5 and 12 years, the mean age was 7 years and 7 months +/- 10 months. Consanguinity rate and coefficient were respectively 44% and 2249 x 10(5). Endogamy was very high. The global rate of hemoglobin abnormalities was 9.4%. Drepanocytosis with a rate of 4.9% was the most frequent, followed by beta thalassemia (3.1%) and C hemoglobinosis (1.6%). These abnormalities were unequally distributed; very frequent in some localities, they were quite absent in others. CONCLUSIONS: This study revealed a hemoglobinosis concentration in Tunisia, which can be classified second after that of Beja in North-western Tunisia. The heterogeneous distribution of the hemoglobin abnormalities in North-Kebili region and the high consanguinity and endogamy rates constitute factors that promote homozygous and double heterozygous forms to arise and justify the elaboration of a preventive strategy.

[Markers of viral hepatitis in blood donors. Study apropos of 300 donors]. / Les marqueurs des hépatites virales chez les donneurs de sang. Etude à propos de 300 donneurs.

In order to locate the rate of positivity of the different markers of hepatitis that can be transmitted through blood (Ag HBs, anti-HBc Ab, anti-HCV Ab and transaminases (ALAT)), we have conducted a study over 300 blood donors and who are sale, equally shared between the parts of age and of sex. The ALAT were superior to the normalcy in 10.66% of the cases, the male sex being 3 times more affected than that of the female. The Ag HBs was positive in 4.66% of the cases. The male sex is twice as affected as the female sex. One of three persons who donated blood (37.33%) had anti-HBc Ab. Finally none of the 300 blood donors has the anti-HCV Ab. There's a very weak recovering between the presence of Ag HBs and of ALAT superior to the normalcy, a weak recovering between Ag HBs and anti-HBc Ab and a certain recovering between ALAT superior to the normalcy and the présence of anti-HBc Ab. There is no recovering between the anti-HCV Ab and the indirect markers. Eventually, the systematization of all these tests over each donation engenders the elimination of more than 2/5 of the collected products.

[Hemoglobin beta S haplotype in the Kebili region (southern Tunisia)]. / Etude de l'haplotype beta S de l'hémoglobine dans la région de Kebili (Sud tunisien).

Sickle cell anemia is a monogenic hereditary disease characterized by a mutation in the beta globin gene. Five major haplotypes associated with the beta S mutation have been defined: Benin, Bantu, Senegalian, Camerounian, and Arabo-Indian. Previous studies in northern Tunisia showed that sickle cell anemia was of Benin origin in this region. Patients from the south of Tunisia, mainly from the Kebili region, were not previously concerned. In this study, we have determined the beta S haplotype and evaluated phenotypical expression of the disease in 14 patients from this latter region. The use of four restriction endonucleases having polymorphic sites in the beta globin gene showed that all patients had the Benin haplotype, confirming the Benin origin of sickle cell anemia in Tunisia. This haplotype is associated with an heterogeneous expression of fetal hemoglobin (HbF) with extremes varying from 2.4 to 16.3% and a mean expression rate of 8.16%, which is in accordance with literature data. In spite of the haplotype homogeneity in our patients, clinical heterogeneity was noted. A unique case of alpha-thalassemia could not explain this heterogeneity. In contrast, we found a certain correlation between fetal hemoglobin expression and clinical severity.

[Low dose cytarabine in the treatment of acute myeloid leukemia. Apropos of 41 cases]. / Cytarabine à faible dose dans le traitement des leucémies aiguës myéloïdes. A propos de 41 cas.

This is a retrospective study on the use of cytarabine at low doses in acute myeloid leukemias in 41 patients. Four groups of AML are included: group A: 19 cases of de novo AML in elderly patients; group B: ten cases of AML in relapse; group C: five cases of AML refractory to previous treatment and group D: seven cases of secondary AML. Cytarabine was given subcutaneously at the dose of 10 mg/m2 of body surface, for 21 days per month for the first course; then 15 days per month for the following courses. The response rates were 42, 20, 0, and 43% respectively for the A, B, C, and D groups. A complete remission was attained in only 15% (six patients). Extra haematological tolerance was excellent. Infection complications were noted in 66%, whereas a severe neutropenia was observed in 34% of patients. Hemorrhagic complications were more rare (20% of patients). The mean duration of complete remission was 10 months. The median survival was 10.5 months (2 to 31 months) for the responder patients, and 2.4 months (1 to 7 months) for the non-responders. Cytarabine at low doses seems to be a good indication for first intention treatment of AML in elderly patients. It does not give a bone marrow aplasia, the infection and hemorrhagic episodes are less numerous than with conventional dose chemotherapy, the life quality is improved, and treatment at home is often possible.

[Treatment of aplastic anemia with cyclosporine, prednisolone and androgens (primary results apropos of 10 cases]. / Traitement de l'aplasie médullaire par ciclosporine, prednisolone et androgènes (résultats préliminaires à propos de 10 cas).

Aplastic anaemia is a potentially fatal haematopoietic disorder whose aetiology is not yet clarified. In our preliminary study we have introduced cyclosporin in the aplastic anaemia treatment to evaluate its effect on the disease evolution. Ten aplastic anaemia patients, mean age 33.33 +/- 20.01 years, were treated with cyclosporine (9 +/- 2.35 mg/kg/d), prednisolone (0.5 mg/kg/d) and androgens (1 mg/kg/d). The prednisolone was always combined with cyclosporine. The androgens were administered concomitantly with the cyclosporine or alternately. Seven patients responded to the treatment after a median remission delay of 6 weeks (2-12 weeks). They became independent of blood requirements at a median of 36 weeks (8-108 weeks); the three other patients died during the first trimester without showing any improvement. Among the seven responders, two relapsed early and transiently. The rate of actuarial survival was 70 per cent. The median duration of survival was 10.5 months. The side effects observed included one case of malignant lymphoma, six cases of liver toxicity and five cases of kidney toxicity. This toxicity was reversible after dose adjustment of the cyclosporine. In our study, the introduction of cyclosporin in the aplastic anaemia treatment resulted in improved therapeutic response. Androgens should be used to maintain the haematologic response. This therapeutic protocol associated with drug monitoring seems promising and the side effects should not limit its use because of the severity of the underlying disease.