Red blood cell alloimmunizations in beta-thalassemia patients in Casablanca/Morocco: Prevalence and risk factors

Red blood cell alloimmunization is one of the major challenges to regular transfusions in β-thalassemic patients. In Morocco, rare studies have focused on this hemoglobinopathy.

OBJECTIVE

We aimed to study the prevalence and risk factors of red cell alloimmunization in β-thalassemic patients.

PATIENTS AND METHODS

Retrospective study during 9 years (2009-2018) was conducted on 160 β-thalassemic patients transfused regularly in pediatric department of children's hospital in Casablanca, Morocco. The main clinical, demographic and transfusional characteristics of alloimmunized and non-alloimmunized patients were compared. Red blood cells units transfused were leukodeplated and phenotypically matched for RH-KELL systems and for other systems after immunization. Screening and antibody identification were performed by gel-filtration method on BIO-RAD caseds using 3 and 11 red blood cells panels. To detect autoantibodies, autocontrol and direct antiglobulin tests were carried out using polyspecific coombs (IgG/C3d) gel cards.

RESULTS

The prevalence of alloimmunizations was 8.75% during the study period. Seventeen alloantibodies identified were directed mainly against antigens of KELL and RH systems: KEL 1 (35.29%), RH 3 (23.52%), RH1 (11.76%), Kpa (11.76%), RH2 (5.88%). Red blood cells autoantibodies had been detected in 6 of 14 (42.85%) of alloimmunized patients versus 12 of 146 (11.76%) of non-alloimmunized patients (P<0.01). Presence of autoantibodies, transfusional interval<3weeks and gender were associated with high rate of red cells alloimmunization.

CONCLUSION

This study proves the data of literature. The presence of red cell autoantibodies appears to be a major risk factors for alloimmunization in thalassemic children, and could advocate specific transfusion guidelines.

[Hemogram profile and interest of pre-donation hemoglobin measurement in blood donors in the northwest region of Morocco]

BACKGROUND

Blood donation in Morocco and more particularly in the northwest region is carried out without prior determination of the pre-donation hemoglobin. In addition, we note the lack of scientific research that reports data on the red blood cells, leukocytes and platelet lines in donated blood at the regional or even national level.

AIMS

To study hemogram profile in blood donors taken from the Northwest region of Morocco in order to provide decision makers of the National Center of Blood Transfusion and Hematology with valid scientific arguments to complete the criteria to donate whole blood, by the hemogram.

METHODS

Prospective study, conducted in 15797 volunteer blood donors (BD) aged between 18 and 60 years, collected during mobile or fixed collections carried out by the Regional Blood Transfusion Center of Tangier and Tetouan from November 2014 to May 2016. The hemogram was performed using a Sysmex KX21N^® and the analysis of the data was done by the software SPSS 20.0.

RESULTS

According to the World Health Organization, anemia corresponds to a hemoglobin level less than 12g/dL in women and less than 13g/dL in men. We found that 14.5 % of women (n=1054) and 3.0 % of men (n=245) were anemic and anemia was hypochromic microcytic in 58,66 % of these BD. Analysis of the white line showed leucopenia in 2.05 % of BD and 807 cases of leukocytosis (5.27 % of BD). Platelet study showed thrombocytopenia in 3.97 % of BD and thrombocytosis in 151BD (0.99 % of cases).

CONCLUSION

This study shows the interest of systematic pre-donation hemoglobin measurement and periodic realization of the hemogram among BD in the Northwest region of Morocco.

Hepatitis B in Moroccan blood donors: a decade trend of the HBsAg prevalence in a resources limited country

OBJECTIVES

To calculate the hepatitis B surface antigen (HBsAg) reactive rate for 2011 blood donors (BD) across Morocco. In addition, to monitor the profile of donors bearing the HBsAg during 2000 and 2011, we calculated the percentage of the prevalence in both sexes, in different age groups and in first-time replacement and regular BD from the Rabat Regional Blood Transfusion Centre.

BACKGROUND

Hepatitis B is a viral infection that spreads through blood and other biological fluids. The hepatitis B virus remains one of the most common serious complications of transfusion. No information exists on the real prevalence of hepatitis B in Moroccan BD.

METHODS

For the 2011 national HBsAg reactive rate, the percentage was calculated based on enzyme-linked immunosorbent assay (ELISA) results of the 232 190 blood donations collected around the country. For the Rabat blood Centre, we calculated the hepatitis B sero-prevalence from donations made at the donors' suite during 2000 and 2011.

RESULTS

The national prevalence of HBsAg was 1·34%. The HBsAg variations among different regions was between 0·43 and 2·86%. The Rabat donors' suite hepatitis B prevalence decreased from 2·47% in 2000 to 0·91% in 2011 (P < 0·001). In both years, family/replacement donors were found as safe as first-time BD and female donors were the safest.

CONCLUSIONS

These results, presented for the first time in the country, mapped the hepatitis B distribution across Morocco in a healthy population. The findings of this study could be of great importance in setting up strategies for the recruitment of the BD and keeping blood safety at the highest level.