PB1272 - Impact of the difference in the cutoff point of the values of clotting factors VIII and IX in the definition of women with hemophilia and hemophilia carrier

Tuesday, June 27, 2023

18:30 – 19:30 ET

Room: Exhibition

Presenting Author(s)

Thaís D R Nóbrega

Hematologist
University of São Paulo Medical School
SAO PAULO, Sao Paulo, Brazil

Co-Author(s)

GM

Guilherme A. Maia

Hematologist
Instituto do Cancer do Estado de São Paulo - ICESP
São Paulo, Sao Paulo, Brazil
PV

Paula R. Villaça

Hematologist
Clinics Hospital of the University of São Paulo Medical School
São Paulo, Sao Paulo, Brazil
BS

Bianca Stefanello

Hematologist
Clinics Hospital of the University of São Paulo Medical School
São Paulo, Sao Paulo, Brazil
EO

Erica Okazaki

Hematologist
Clinics Hospital of the University of São Paulo Medical School
São Paulo, Sao Paulo, Brazil
TR

Tania R. F. da Rocha

Head of Hemostasis and Thrombosis Laboratory
Clinics Hospital of the University of São Paulo Medical School
São Paulo, Sao Paulo, Brazil
CR

Cynthia Rothschild, Master (she/her/hers)

Hematologist
ICESP - University of São Paulo Medical School
São Paulo, Sao Paulo, Brazil
FC

Frederica R. M. Y. Cassis

Psychotherapist
University of São Paulo Medical School
São Paulo, Sao Paulo, Brazil
ES

Eliane P. N. Sandoval

Nurse
University of São Paulo Medical School
São Paulo, Sao Paulo, Brazil
FO

Fernanda A. Orsi

Hematologist
University of São Paulo Medical School
São Paulo, Sao Paulo, Brazil

Background: There are different recommendations for the stratification of coagulation factor VIII (FVIII) and IX (FIX) dosage values in order to standardize the classification of women with hemophilia (WWH) and hemophilia carriers.

Aims: to evaluate the differences in the classification of WWH and hemophilia carriers, according to the FVIII or FIX cutoff point of 40 or 50 IU/mL.

Methods: Data of women, with no age restriction, who were followed up at a hemophilia treatment center in the city of São Paulo, Brazil, were evaluated between November and December 2022. Data were collected regarding age and FVIII and FIX dosage values, von Willebrand factor (VWF:Ag), and ristocetin cofactor (VWF:RCo) at diagnosis.

Results: A total of 53 women were included in the study, 40 (75%) of whom were hemophilia carriers or WWH of type A. The median age of participants was 40 years (interquartile range (IQR), 27-53 years), while the median of VWF:Ag was 79 IU/dL (IQR, 58-79 IU/dL) and of VWF:RCo was 81% (IQR 61-114%). Median FVIII dosage was 42% (IQR 28-49%) and FIX was 37% (IQR 25-44%). Considering the women in group A and with a cutoff point of 40 IU/mL, 17 (43%) are classified as WWH and 23 (57%) as hemophilia carriers; while those of type B would be classified as 8 (62%) WWH and 5 (38%) as hemophilia carriers. Considering the cutoff point of 50 IU/mL, the women in group A would be classified as 32 (80%) WWH and 8 (20%) as hemophilia carriers; while the women in group B would be stratified as 11 (85%) WWH and 2 (15%) as hemophilia carriers.

Conclusion(s): There is a need for standardization of the definition of hemophilia carriers and WWH, as a form of guidance in the therapeutic and psychological management of women.