Transfusion in hemoglobinopathies and red blood cell alloimmunization: data from Sicily, Sardinia and Malta.

BACKGROUND: Hemoglobinopathies are a group of diseases that include those due to globin gene mutations, such as thalassemia major (TM) and thalassemia intermedia (TI) or due to alteration of hemoglobin structure such as sickle cell disease (SCD), as well as a combination of these conditions such as thalasso-drepanocytosis (TD). They constitute the most frequent hereditary anemias requiring blood transfusion. MATERIALS AND METHODS: In April 2022, a questionnaire was sent to the Transfusion Services (TS) of Sicily, Sardinia and the Maltese National Blood Transfusion (MNBT) service. The questionnaire was divided into a generic part including the number of patients followed and the type of hemoglobinopathy, and a section relating to transfusion therapy, including the number of units transfused, whether red blood cells (RBC) were washed and, finally, a section relating to the presence or absence of alloantibodies and their identification. RESULTS: Data was retrieved for 2,574 patients: 68.6% TM, 15.4% TI, 10.3% TD, 4.1% SCD, and 1.6% other hemoglobinopathies (OHA). The number of RBC units transfused was 76,974, equivalent to 24.5% of all the RBCU transfused from the total number of patients followed. The number of washed RBCU was 21.1% of all the units used; 337 patients (37%) were diagnosed with alloantibodies, the majority of which were patients with SCD (20.6%). Of the 485 alloantibodies found, 90.3% were identified. The antibodies found most frequently were related to the Kell system (41.7%) followed by antibodies to the Rhesus system (37.9%); 29.7% of patients had more than one antibody. DISCUSSION: From our study, certain indications can be formulated: complete the National Registry for patients with hemoglobinopathies; create a Registry of alloimmunized patients to ensure transfusion therapy is as safe as possible, considering antibody evanescence; and 3) increase the recruitment of blood donors of diverse ethnicities.

A Particular Focus on the Prevalence of α- and ß-Thalassemia in Western Sicilian Population from Trapani Province in the COVID-19 Era.

Thalassemia is a Mendelian inherited blood disease caused by α- and ß-globin gene mutations, known as one of the major health problems of Mediterranean populations. Here, we examined the distribution of α- and ß-globin gene defects in the Trapani province population. A total of 2,401 individuals from Trapani province were enrolled from January 2007 to December 2021, and routine methodologies were used for detecting the α- and ß-globin genic variants. Appropriate analysis was also performed. Eight mutations in the α globin gene showed the highest frequency in the sample studied; three of these genetic variants represented the 94% of the total α-thalassemia mutations observed, including the -α3.7 deletion (76%), and the tripling of the α gene (12%) and of the α2 point mutation IVS1-5nt (6%). For the ß-globin gene, 12 mutations were detected, six of which constituted 83.4% of the total number of ß-thalassemia defects observed, including codon ß039 (38%), IVS1.6 T > C (15.6%), IVS1.110 G > A (11.8%), IVS1.1 G > A (11%), IVS2.745 C > G (4%), and IVS2.1 G > A (3%). However, the comparison of these frequencies with those detected in the population of other Sicilian provinces did not demonstrate significant differences, but it contrarily revealed a similitude. The data presented in this retrospective study help provide a picture of the prevalence of defects on the α and ß-globin genes in the province of Trapani. The identification of mutations in globin genes in a population is required for carrier screening and for an accurate prenatal diagnosis. It is important and necessary to continue promoting public awareness campaigns and screening programs.