title: Thrombotic Thrombocytopenic Purpura in Black People: Impact of Ethnicity on Survival and Genetic Risk Factors.
abstract: Black people are at increased risk of thrombotic thrombocytopenic purpura (TTP). Whether clinical presentation of TTP in Black patients has specific features is unknown. We assessed here differences in TTP presentation and outcome between Black and White patients. Clinical presentation was comparable between both ethnic groups. However, prognosis differed with a lower death rate in Black patients than in White patients (2.7% versus 11.6%, respectively, P = .04). Ethnicity, increasing age and neurologic involvement were retained as risk factors for death in a multivariable model (P < .05 all). Sixty-day overall survival estimated by the Kaplan-Meier curves and compared with the Log-Rank test confirmed that Black patients had a better survival than White patients (P = .03). Salvage therapies were similarly performed between both groups, suggesting that disease severity was comparable. The comparison of HLA-DRB1*11, -DRB1*04 and -DQB1*03 allele frequencies between Black patients and healthy Black individuals revealed no significant difference. However, the protective allele against TTP, HLA-DRB1*04, was dramatically decreased in Black individuals in comparison with White individuals. Black people with TTP may have a better survival than White patients despite a comparable disease severity. A low natural frequency of HLA-DRB1*04 in Black ethnicity may account for the greater risk of TTP in this population.
authors.affiliation: Service d'Hématologie, Hôpital Saint-Antoine, AP-HP, Paris, France.|Centre de Référence des Microangiopathies Thrombotiques, Hôpital Saint-Antoine, AP-HP, et UPMC Univ Paris 06, Paris, France.
authors.forename: Suella
authors.initials: S
authors.lastname: Martino
authors.affiliation: Centre de Référence des Microangiopathies Thrombotiques, Hôpital Saint-Antoine, AP-HP, et UPMC Univ Paris 06, Paris, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Jamme
authors.affiliation: Service de Médecine interne, CHU de Fort-de France, Fort-de-France, Martinique, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Deligny
authors.affiliation: AP-HP, Laboratoire Jean Dausset d'Immunologie et d'Histocompatibilité & INSERM, UMRS 1160, Hôpital Saint Louis, Sorbonne Paris Cité, Paris, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Busson
authors.affiliation: AP-HP, Laboratoire Jean Dausset d'Immunologie et d'Histocompatibilité & INSERM, UMRS 1160, Hôpital Saint Louis, Sorbonne Paris Cité, Paris, France.
authors.forename: Pascale
authors.initials: P
authors.lastname: Loiseau
authors.affiliation: Centre de Référence des Microangiopathies Thrombotiques, Hôpital Saint-Antoine, AP-HP, et UPMC Univ Paris 06, Paris, France.|Université Paris Diderot, Paris, France.|Service de Réanimation Médicale, Hôpital Saint-Louis, AP-HP, Paris, France.
authors.forename: Elie
authors.initials: E
authors.lastname: Azoulay
authors.affiliation: Centre de Référence des Microangiopathies Thrombotiques, Hôpital Saint-Antoine, AP-HP, et UPMC Univ Paris 06, Paris, France.|Université Paris Diderot, Paris, France.|Service d'Immunologie clinique, Hôpital Saint-Louis, AP-HP, Paris, France.
authors.forename: Lionel
authors.initials: L
authors.lastname: Galicier
authors.affiliation: Centre de Référence des Microangiopathies Thrombotiques, Hôpital Saint-Antoine, AP-HP, et UPMC Univ Paris 06, Paris, France.|Service de Réanimation Médicale, Hôpital Cochin, AP-HP, Paris, France.|Université Paris 5, Paris, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Pène
authors.affiliation: Centre de Référence des Microangiopathies Thrombotiques, Hôpital Saint-Antoine, AP-HP, et UPMC Univ Paris 06, Paris, France.|Service de Néphrologie, Hôpital Albert Calmette, Lille, France.
authors.forename: François
authors.initials: F
authors.lastname: Provôt
authors.affiliation: Centre de Référence des Microangiopathies Thrombotiques, Hôpital Saint-Antoine, AP-HP, et UPMC Univ Paris 06, Paris, France.|Service de Médecine Interne, Hôpital Bichat, AP-HP, Paris, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Dossier
authors.affiliation: Centre de Référence des Microangiopathies Thrombotiques, Hôpital Saint-Antoine, AP-HP, et UPMC Univ Paris 06, Paris, France.|Service de Médecine interne 1, Hôpital La Pitié-Salpêtrière, AP-HP, Paris, France.
authors.forename: Samir
authors.initials: S
authors.lastname: Saheb
authors.affiliation: Centre de Référence des Microangiopathies Thrombotiques, Hôpital Saint-Antoine, AP-HP, et UPMC Univ Paris 06, Paris, France.|Université Paris Diderot, Paris, France.|Service d'Hématologie Biologique, Hôpital Lariboisière, AP-HP, Paris, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Veyradier
authors.affiliation: Service d'Hématologie, Hôpital Saint-Antoine, AP-HP, Paris, France.|Centre de Référence des Microangiopathies Thrombotiques, Hôpital Saint-Antoine, AP-HP, et UPMC Univ Paris 06, Paris, France.|Sorbonne Université, UPMC Univ Paris 06, Paris, France.|Inserm U1009, Institut Gustave Roussy, Villejuif, France.
authors.forename: Paul
authors.initials: P
authors.lastname: Coppo
mesh_terms: D000328:Adult; D001741:Black or African American / Q000235:genetics*; D000483:Alleles; D044383:Black People / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D059866:HLA-DQ beta-Chains / Q000235:genetics; D059811:HLA-DRB1 Chains / Q000235:genetics; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011697:Purpura, Thrombotic Thrombocytopenic / Q000208:ethnology* / Q000235:genetics* / Q000401:mortality; D012042:Registries; D012307:Risk Factors; D016896:Treatment Outcome; D044465:White People / Q000235:genetics
chemical_list: D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D059811:HLA-DRB1 Chains; C527195:HLA-DRB1*04 antigen; C508422:HLA-DRB1*11 antigen