Seroprevalency of transfusion-transmitted infections in first-time volunteer and replacement donors in Tunisia

BACKGROUND

Replacement donors are considered as having a major risk of transmission of infections to recipients mainly by the World Health Organisation.

STUDY DESIGN AND METHODS

Seroprevalency of HBV, HCV, HIV and syphilis were determined in 19,783 whole blood donations collected in the Tunisian National Blood Transfusion Centre during the year 2010 (12,968 [65.55%] replacement donations and 6815 [34.44%] voluntary blood donations). For HBV, HCV and syphilis, we performed a univariate analysis to determine whether age, sex and type of donation were risk factors, then multivariate logistic regression, to see if these factors were independent.

RESULTS

Mean age of donors was 30.1 years (replacement donors 34.5 years, first time non-remunerated donors 34.5 years, P<0.001). The predominant age group was 30-39 years (35.51%) in replacement donors and 20-29 years (54.15%) in first time non-remunerated donors. Male gender was significantly predominant (73.00% men vs 27.00% women, P<10(-6)). There were significantly more men among replacement donors (82.27% vs 55.38%, P<10(-3)). There were more women in the age groups 18-19 and 20-29 years. Only one HIV seropositive donation was noted in a male first time non-remunerated donor aged 18. Replacement type of donation, male sex and age were three independent risk factors for the HBs Ag carriage. For anti-HCV antibodies and TPHA, only replacement type of donation and age were found out to be risk factors and only age was independent.

CONCLUSION

In Tunisia, replacement blood donors were at higher risk of infection transmission, but only for hepatitis B.

[Anti-erythrocyte and anti-HLA immunization in hemoglobinopathies]

AIM

Evaluate the anti-erythrocyte and anti-HLA immunization rates in hemoglobinopathies.

PATIENTS AND METHODS

Cross-sectional study (October 2009-March 2010) on 83 patients followed for hemoglobinopathies. The irregular antibodies research is realized by two techniques: indirect Coombs and enzymatic technique on gel cards. The search for anti-HLA class I antibodies is done by complement dependent lymphocytotoxicity.

RESULTS

The mean age was 30 years (14-64 years), the sex ratio M/F is 0.84. Our series included 42 cases of sickle cell disease (29 homozygous sickle cell anemia and 13 sickle-thalassemia) and 41 cases of thalassemia syndromes (26 major and 15 intermediate). The anti-erythrocyte alloimmunization rate is 10.84% without difference between thalassemia syndromes and sickle cell disease. The autoimmunization rate (22.89%) is higher in thalassemia syndromes (41.46%) than in the sickle cell disease (7.14%) (P<0.001). The anti-HLA immunization rate is 31.6% without difference between thalassemia syndromes and sickle cell disease. The young age, transfusion at a young age and the total number of transfusions are the factors that increase the risk of anti-erythrocyte autoimmunization. No clinicobiological parameter does influence the anti-erythrocyte and anti-HLA alloimmunization. There is no significant association between anti-erythrocyte and anti-HLA immunization.

CONCLUSION

The erythrocyte and anti-HLA anti-immunization rates are high in our series. Preventive strategy is needed to ensure optimal blood safety.

[Lineage assignment in acute leukemia: confrontation between cytology and immunophenotyping]

OBJECTIVE

The determination of the cellular lineage in acute leukemia is a crucial step in the diagnosis and the later therapeutic conduct. In Tunisia, emerging country, some cases of acute leukemias are still treated on the basis of an only cytologic study because of lack of cytometry. Our objective is to realize a confrontation between cytology and flow cytometry in the diagnosis of AL and to analyze discrepancies.

PATIENTS AND METHODS

The study concerns 100 cases of AL. A second double-blind examination of the bone marrow smears of acute leukemias is realized by two cytologists and confronted to immunophenotyping.

RESULTS

In two cases of AML, flow cytometry reassigned lineage into T ALL and biphenotypic AL. In three cases of ALL the lineage was reassigned into undifferentiated acute leukemia (2 cases) and biphenotypic acute leukemia (1 case). Lineage was not established in four cases, immunophenotyping allowed the diagnosis of B ALL in 3 cases, and of biphenotypic acute leukemia in 1 case. In both cases of discrepant findings, flow cytometry allowed the diagnosis of biphenotypic acute leukemia in a case and of AML in the other one.

CONCLUSION

The cytological study remains insufficient in the diagnosis of lineage even with experimented cytologists. Immunophenotyping is essential in lineage assignment and reassignment.

Analysis of newly detected mutations in the MCFD2 gene giving rise to combined deficiency of coagulation factors V and VIII

Combined deficiency of coagulation factor V (FV) and factor VIII (FVIII) (F5F8D) is a rare autosomal recessive disorder characterized by mild-to-moderate bleeding and reduction in FV and FVIII levels in plasma. F5F8D is caused by mutations in one of two different genes, LMAN1 and MCFD2, which encode proteins that form a complex involved in the transport of FV and FVIII from the endoplasmic reticulum to the Golgi apparatus. Here, we report the identification of a novel mutation Asp89Asn in the MCFD2 gene in a Tunisian patient. In the encoded protein, this mutation causes substitution of a negatively charged aspartate, involved in several structurally important interactions, to an uncharged asparagine. To elucidate the structural effect of this mutation, we performed circular dichroism (CD) analysis of secondary structure and stability. In addition, CD analysis was performed on two missense mutations found in previously reported F5F8D patients. Our results show that all analysed mutant variants give rise to destabilized proteins and highlight the importance of a structurally intact and functional MCFD2 for the efficient secretion of coagulation factors V and VIII.

Molecular analysis in two Tunisian families with combined factor V and factor VIII deficiency

SUMMARY

Combined factor V (FV) and factor VIII (FVIII) deficiency (F5F8D) is a rare autosomal recessive disorder caused by mutations in LMAN1 or MCFD2 genes which encode proteins that form a complex involved in the transport of FV and FVIII from the endoplasmic reticulum to Golgi apparatus. We report two novel mutations in MCFD2 gene and one recurrent mutation in LMAN1 gene that caused combined FV and FVIII deficiency in two unrelated Tunisian Muslim families. For the first family two patients were homozygous for a new missense mutation Asp81His in exon 3 of MCFD2 and heterozygous for a second new missense mutation Val100Asp in the same exon. Replacement respectively of the hydrophilic Asp residue with hydrophobic positively charged His and of the hydrophobic neutral Val residue with the Asp residue most likely disrupts the MCFD2-LMAN1 interaction, thus leading to the disease phenotype. For the second family a reported Arg202X mutation in exon 5 in the LMAN1 gene was identified in the homozygous state.

[Cytology and immunophenotyping of acute promyelocytary leukaemia]

Acute promyelocytic leukaemia (AML3) is characterized by particular clinical and biological features. We report the cytology and the immunophenotype of 14 AML3 from which 3 were AML3v. A double negativity of HLA-DR and CD34 is found in 12 cases and aberrant expression of CD2 in 2AML3v. Aberrant expression of CD56 and CD22 was shown in, respectively, one case, CD15, CD65 and CD117 expressions were variable. Cytological diagnosis is often evident, although in some cases, it is not typical and immunophenotype will contribute to the diagnosis.

[Blood-transmitted viral infections among haemophiliacs in Tunisia]

In this work, we proposed to evaluate prevalences of hepatitis B and C viruses and Parvovirus B19 among 70 Tunisian haemophiliacs treated with clotting factors imported from Europe and/or locally produced cryoprecipitate; among them 6 (8.6%) are known HIV positive patients. HBs antigen, anti-HBc antibodies and anti-Parvovirus B19 antibodies were detected in 7.1%, 52.9% and 91.8%, respectively. HCV prevalence, defined as positive ELISA with positive Immunoblot and/or PCR was 50.0%. Prevalences of these viral infections in haemophiliacs are higher than prevalences detected among general population and in the control group of the study. HCV infection is less frequent in haemophiliacs born after 1985, the year of introduction of the inactivation procedures in the production of coagulation factors concentrates; it decreases more considerably after 1994, date of introduction of systematic screening of HCV among blood donors. In contrast, despite the inactivation of the factors concentrates and the systematic screening of the blood donations against HBs antigen, since 1973, the risk of HBV infection contamination remains high in the Tunisian haemophiliacs. The introduction in 1995 of hepatitis B vaccination in the national schedule of new-born vaccination may resolve in the future the problem of HBV infection in haemophiliacs and in the other categories of the Tunisian population.

Syndromes de défibrination atypiques et leucémies aiguës à translocation t(9,22) ; à propos de deux observations

We report two cases of atypical defibrination syndromes in patients with respectively acute monoblastic leukemia (chronic myeloid leukemia initially) and acute lymphoblastic leukemia. Hemostasis studies show low fibrinogen level, elevated D-dimers, decreased alpha 2 antiplasmin and factor V, normal antithrombin III values. Plasminogen is below the normal range in one patient. Soluble complexes, which are an important argument for diagnosis of intravascular coagulation disease, are not detected in both patients. Primary or secondary hyperfibrinolysis seems also excluded since euglobulin clot lysis time was normal. Enzymatic proteolysis of fibrinogen (or fibrin) by the blast cells has been reported by some authors; this mechanism could account for the hemostasis abnormalities observed in these two patients.

[Long-term survival and prognostic factors in multiple myeloma treated with conventional chemotherapy. Report of 109 cases]

Our study is retrospective. We report the results of conventional chemotherapy ins previosly untreated patients with myeloma. Survival and prognostic factors were analysed in 109 patients diagnosed from 1983 to 1992. The median age was 65 years, 87 patients (80%) were including in the stage III according the Durie Salmon staging system. The median survival time was 27 months and 10 years survival rate is 3.66%. In the univariate analysis, two prognostic variables were retained namely the hemoglobin and creatinine level. The study suggest that conventional therapy is a good treatment for old patients. However, patients younger than 55 years, must benefit from intensive chemotherapy supported by autologous bone marrow, pheripheral blood stem cells, or allogenic bone marrow transplantation. A considerable encrace in duration of remission and survival is possible.

[The 5q(-) syndrome. Report of 2 cases]

A rare and primitive myelodysplastic syndrome 5q(-) is characterised first, by the persistence of the cytogenetic anomaly 5q(-), and second, by its feminine predominance. Among 13 cases of myelodysplastic syndromes, the subject of a substantial and systematic cytogenetic medullar study (1996-1998), this paper is a case study of 2 syndromes 5q(-) diagnosed in two male patients, respectively, aged 41 and 68. The following diagnosis was made on the basis of an aregenerative macrocytic anaemia, a high platelet count, and a megakaryocytic hyperplasia, along with dysmegakaryocytopoiesis. The diagnosis of the 5q(-) syndrome was verified by cytogenetic analysis showing in one of the patients a deletion 5q(-)(q13, q33) and 5q(-)(q14, q34) with trisomy in the second one. Treatment was only limited to a blood transfusion. Subsequently one of the patients developed an advanced case of leukaemia. This paper suggests that a systematic medullar cytogenetic study must be conducted in the case of any refractory anaemia in order to identify the syndrome 5q(-) in individual cases.