Contributions
Abstract: PB1816
Type: Publication Only
Session title: Thalassemias
Background
Transfusions, oxidative stress splenectomy, as well as iron overload have been correlated to immune defects in transfusion dependent thalassemia patients. However, literature reports on immunoglobulin levels in this patient population remain contradictory. On the other hand, hyper reaction to constant immune challenges has also been a topic of controversy.
Aims
Τo evaluate the immune profile of pediatric multi - transfused patients with beta thalassemia.
Methods
The study group consisted of pediatric transfusion dependent thalassemia patients followed at a single Pediatric Hematology Department. Patients with a history of splenectomy, active autoimmune disease, active severe infection or any systemic condition that could affect the immune profile were excluded. Blood samples were collected from all subjects for evaluation of immunoglobin levels, C3 and C4 complement factors, red cell auto-antibodies, as well as antinuclear (ANA), and anti-double stranded DNA (anti-sdDNA), anti-thyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-TG) antibodies. Clinical and laboratory data were obtained from chart reviews, including demographics, presence of severe infections, duration of transfusion, history of allo-immunization, chelation therapy, heart T2* ΜRΙ and Liver Iron Concentration (LIC), as well as mean annual hemoglobin and ferritin levels.
Results
In total, 24 patients enrolled in the study. Mean patient age was 13.3 (2–19) years and 18/24 (75%) were males. No record of severe infection was noted. Mean annual pre-transfusion hemoglobin level was 9.5±0.48 (8.5-10.3) g/dl and mean annual ferritin level 1,228±538 (409-2,627) ng/ml. Mean duration of transfusion therapy was 9.6±5 (1.5–18) years. All except one patient were on chelation therapy. In specific, 12/23 patients (52.1%) were on deferasirox, 4/23 (17.3%) on deferiprone, 2/23 (8.6%) on deferoxamine 4/23 (17.3%) on deferoxamine / deferiprone combination and 1/23 (4.3%) on deferasirox / deferiprone combination. In 21/24 patients an annual MRI evaluation was available, with a mean heart Τ2* value of 32.01±6.19 (22.3-49) ms and a mean LIC of 8.05± 9.3 (1.28-32.9) mg/gdw.
With respect to immunoglobulin levels, mean IgG levels were 9.94±2.7 (6.3–15.1) gr/l with 7/24 (29.1%) patients presenting with lower than normal values, mean IgM levels were 1.1±0.6 (0.47 – 2.2) gr/l with 5/24 (20.8%) patients presenting with lower than normal values and mean IgA levels were 1.56±0.7 (0.6-3.38)gr/l with 2/24 (8.3%) patients presenting with lower and 2/24 patients (8.3%) with higher than normal levels. In total 10/24 patients (41.6%) and 1/24 (4.1%) had lower C3 and C4, respectively, with mean values of 0.77±0.14 (0.53 – 1.06) gr/l and 0.17±0.05 (0.09 – 0.28) gr/l. Positive ANA titres of ≥ 1:80 were found in 7/24 patients (29.1%) whereas no patient presented with positive anti-ds DNA, anti – TPO, anti- TG or red cell auto-antibodies. In total, 4/24 (16.6%) patients presented with a positive indirect Coombs test. No significant correlation was found between immunoglobulin levels, complement factors levels or autoantibody presence with age, duration of transfusion, allo-immunization, chelation therapy or iron overload.
Conclusion
The present study revealed an abnormal immune profile in a number of transfusion dependent pediatric patients, although no correlation to parameters studied was made. Larger prospective studies are needed in order to identify clinical relevance of the reported findings.
Keyword(s): Beta thalassemia, Complement, Immunoglobulin, Iron overload
Abstract: PB1816
Type: Publication Only
Session title: Thalassemias
Background
Transfusions, oxidative stress splenectomy, as well as iron overload have been correlated to immune defects in transfusion dependent thalassemia patients. However, literature reports on immunoglobulin levels in this patient population remain contradictory. On the other hand, hyper reaction to constant immune challenges has also been a topic of controversy.
Aims
Τo evaluate the immune profile of pediatric multi - transfused patients with beta thalassemia.
Methods
The study group consisted of pediatric transfusion dependent thalassemia patients followed at a single Pediatric Hematology Department. Patients with a history of splenectomy, active autoimmune disease, active severe infection or any systemic condition that could affect the immune profile were excluded. Blood samples were collected from all subjects for evaluation of immunoglobin levels, C3 and C4 complement factors, red cell auto-antibodies, as well as antinuclear (ANA), and anti-double stranded DNA (anti-sdDNA), anti-thyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-TG) antibodies. Clinical and laboratory data were obtained from chart reviews, including demographics, presence of severe infections, duration of transfusion, history of allo-immunization, chelation therapy, heart T2* ΜRΙ and Liver Iron Concentration (LIC), as well as mean annual hemoglobin and ferritin levels.
Results
In total, 24 patients enrolled in the study. Mean patient age was 13.3 (2–19) years and 18/24 (75%) were males. No record of severe infection was noted. Mean annual pre-transfusion hemoglobin level was 9.5±0.48 (8.5-10.3) g/dl and mean annual ferritin level 1,228±538 (409-2,627) ng/ml. Mean duration of transfusion therapy was 9.6±5 (1.5–18) years. All except one patient were on chelation therapy. In specific, 12/23 patients (52.1%) were on deferasirox, 4/23 (17.3%) on deferiprone, 2/23 (8.6%) on deferoxamine 4/23 (17.3%) on deferoxamine / deferiprone combination and 1/23 (4.3%) on deferasirox / deferiprone combination. In 21/24 patients an annual MRI evaluation was available, with a mean heart Τ2* value of 32.01±6.19 (22.3-49) ms and a mean LIC of 8.05± 9.3 (1.28-32.9) mg/gdw.
With respect to immunoglobulin levels, mean IgG levels were 9.94±2.7 (6.3–15.1) gr/l with 7/24 (29.1%) patients presenting with lower than normal values, mean IgM levels were 1.1±0.6 (0.47 – 2.2) gr/l with 5/24 (20.8%) patients presenting with lower than normal values and mean IgA levels were 1.56±0.7 (0.6-3.38)gr/l with 2/24 (8.3%) patients presenting with lower and 2/24 patients (8.3%) with higher than normal levels. In total 10/24 patients (41.6%) and 1/24 (4.1%) had lower C3 and C4, respectively, with mean values of 0.77±0.14 (0.53 – 1.06) gr/l and 0.17±0.05 (0.09 – 0.28) gr/l. Positive ANA titres of ≥ 1:80 were found in 7/24 patients (29.1%) whereas no patient presented with positive anti-ds DNA, anti – TPO, anti- TG or red cell auto-antibodies. In total, 4/24 (16.6%) patients presented with a positive indirect Coombs test. No significant correlation was found between immunoglobulin levels, complement factors levels or autoantibody presence with age, duration of transfusion, allo-immunization, chelation therapy or iron overload.
Conclusion
The present study revealed an abnormal immune profile in a number of transfusion dependent pediatric patients, although no correlation to parameters studied was made. Larger prospective studies are needed in order to identify clinical relevance of the reported findings.
Keyword(s): Beta thalassemia, Complement, Immunoglobulin, Iron overload