PB0674 - Clinical outcome of the use of hydroxychloroquine in patients with immune thrombocytopenia and antiphospholipid antibodies

Monday, June 24, 2024

13:45 – 14:45 ICT

Room: Exhibition Hall

Co-Author(s)

FP

Fernando Guimaraes Porto

MD
Department of Hematology, Hemotherapy and Cellular Therapy, Hospital das Clinicas of University of São Paulo Medical School (HCFMUSP)
São Paulo, Sao Paulo, Brazil
GL

Giselle Lima

MD
Department of Hematology, Hemotherapy and Cellular Therapy, Hospital das Clinicas of University of São Paulo Medical School (HCFMUSP)
São Paulo, Sao Paulo, Brazil
EO

Erica Okazaki

MD
Department of Hematology, Hemotherapy and Cellular Therapy, Hospital das Clínicas of University of São Paulo Medical School (HCFMUSP), São Paulo, Brazil
São Paulo, Sao Paulo, Brazil
CR

Cynthia Rothschild

MD
Department of Hematology, Hemotherapy and Cellular Therapy, Hospital das Clínicas of University of São Paulo Medical School (HCFMUSP), São Paulo, Brazil
São Paulo, Sao Paulo, Brazil
BS

Bianca Stefanello

MD
Department of Hematology, Hemotherapy and Cellular Therapy, Hospital das Clínicas of University of São Paulo Medical School (HCFMUSP), São Paulo, Brazil
São Paulo, Sao Paulo, Brazil
PP

Paula Prestes

MD, Department of Hematology Hemotherapy and Cellular Therapy
Hospital das Clinicas of University of São Paulo Medical School (HCFMUSP), São Paulo, Brazil
São Paulo, Sao Paulo, Brazil
TR

Tania Rubia Flores da Rocha

Pharmaceutical
Hospital das Clínicas da Faculdade de Medicina da USP, São Paulo, São Paulo, Brazil
São Paulo, Sao Paulo, Brazil
VR

Vanderson Rocha

MD
Department of Hematology, Hemotherapy and Cellular Therapy, Hospital das Clínicas of University of São Paulo Medical School (HCFMUSP), São Paulo, Brazil
São Paulo, Sao Paulo, Brazil
PV

Paula Villaça

Hematologist
Hospital das Clínicas da Faculdade de Medicina da USP, São Paulo, São Paulo, Brazil
São Paulo, Sao Paulo, Brazil
FO

Fernanda Andrade Orsi

MD
Department of Hematology, Hemotherapy and Cellular Therapy, Hospital das Clínicas of University of São Paulo Medical School (HCFMUSP), São Paulo, Brazil
São Paulo, Sao Paulo, Brazil

Presenting Author(s)

Gabrielle de Mello Santos

MD
Department of Hematology, Hemotherapy and Cellular Therapy, Hospital das Clínicas of University of São Paulo Medical School (HCFMUSP), São Paulo, Brazil
Rio de Janeiro, Rio de Janeiro, Brazil

Background: Antiphospholipid antibodies (aPL) are frequently detected in patients with immune thrombocytopenia (ITP), and the question of whether these patients benefit from individualized treatment is controversial.

Aims: To describe a single-center long-term experience with the use of hydroxychloroquine (HCQ) in aPL-positive ITP, focusing on treatment efficacy.

Methods: Retrospective cohort study of aPL-positive ITP since 2000. ITP-related outcomes were compared between patients treated with standard second-line treatment and those treated with standard therapy plus HCQ at 400mg/day. Regression models were adjusted for age, sex, and BMI.

Results: : A total of 68 aPL-ITP patients were included, 66% were women, median age was 47 years-old (IQR 38-66), the majority were white (88%) and 34% were obese. 25% did not require treatment, 25% received standard ITP therapy and the remaining 50% received HCQ-containing regimens. The median duration of HCQ use was 256 days. There was no difference in complete response in patients treated with HCQ-containing regimens compared to standard therapy (50% vs. 71%; p=0.4). The median platelet count for patients treated with HCQ was 83,534/mm3 compared to 139,885/mm3 for patients treated with standard therapy (adjusted mean difference -28,170; 95%CI -90,208, 33,867; p=0.4). No reduction in the incidence of thrombosis or bleeding was observed in the HCQ-treated group. Among the 50% of HCQ responders, a relapse rate of 74% was observed, with a median time to relapse of 14 days. The median time between the end of HCQ use and the need for new treatment was 29 days, with a median of two additional lines of treatment after relapse, mainly a combination of immunosuppressants and eltrombopag.

Conclusion(s): The addition of HCQ to standard ITP therapy had no effect on treatment response, platelet count or hemorrhagic/thrombotic phenotype. The response, when it occurs, is not sustainable. Therefore, the use of HCQ does not appear to improve ITP outcomes in aPL-positive patients.