Send to

Choose Destination
Transfusion. 2014 Feb;54(2):389-97. doi: 10.1111/trf.12263. Epub 2013 May 27.

High prevalence of infectious events in thrombotic thrombocytopenic purpura and genetic relationship with toll-like receptor 9 polymorphisms: experience of the French Thrombotic Microangiopathies Reference Center.

Author information

Service d'Hématologie, Centre de Référence des Microangiopathies Thrombotiques, Hôpital Saint-Antoine, Université Pierre et Marie Curie, Paris, France; Service de Réanimation Polyvalente, Hôpitaux Universitaires de l'Est Parisien, AP-HP et UPMC Univ Paris 06, Paris, France; Inserm U1009, Institut Gustave Roussy, Villejuif, France; Laboratoire Jean Dausset d'Immunologie et d'Histocompatibilité & INSERM, AP-HP, UMRS 940, Paris, France; Service d'Immunopathologie, Service de Réanimation, Hôpital Saint-Louis, Université Paris 7 Denis Diderot, Paris, France; Service de Réanimation Médicale, Hôpital Charles Nicolle, Rouen, France; Service de Néphrologie, Hôpital Maison Blanche, Reims, France; Service de Néphrologie, Centre Hospitalier Universitaire, Lille, France; Service d'Hémaphérèse, Service de Médecine Interne, Hôpital de la Conception, Marseille, France; Service de Néphrologie, Centre Hospitalier de Valenciennes, Valenciennes, France; Service de Néphrologie- Médecine Interne, Hôpital Sud, Amiens, France; Service d'Hématologie Clinique et de Thérapie Cellulaire, CHU Dupuytren, Limoges, France; Service de Néphrologie, Hôpital Pellegrin, Bordeaux, France; Service Médecine Interne A, Hôpital Hôtel-Dieu, Nantes, France; Service de Néphrologie, Dijon, France; Service de Néphrologie, Hôpital Pontchaillou, Rennes, France; Service de Réanimation Médicale (7HO), Hôpital Gabriel Montpied, Clermont-Ferrand, France; Service de Néphrologie et Immunologie Clinique, CHU Rangueil, Toulouse, France; Service de Réanimation Polyvalente, AP-HP, Hôpital Cochin, Université Paris 5, Paris, France; Service de Réanimation Néphrologique, Hôpital Tenon, UPMC Université Paris 06, Paris, France; Service d'Hématologie, Hôpital Emile Muller, Mulhouse, France; Service d'Hématologie Biologique, Hôpital Antoine Béclère, AP-HP, Clamart et Université Paris-Sud 11, Le Kremlin-Bicêtre, France.



Infectious events have been reported as major environmental triggers of thrombotic thrombocytopenic purpura (TTP). We detail here the potential association between infections and TTP.


We recruited randomly and prospectively a cohort of 280 consecutive TTP patients during a 9-year period. Features of infection were systematically recorded.


Features consistent with an infectious event were observed in 114 patients (41%) at time of TTP diagnosis. Infectious agents were documented in 34 cases and were mainly Gram-negative bacilli. At time of diagnosis infected patients more frequently had fever (p < 0.001). Infections at diagnosis did not impact prognosis and outcome. Thirty-six percent of patients experienced an infectious event during hospitalization, which resulted in more exacerbation of TTP (p = 0.02). Infections were not overrepresented during treatment in patients who received steroids and/or rituximab. Further genetic analysis of toll-like receptor (TLR)-9 functionally relevant polymorphisms revealed that TLR-9 +2848 G and TLR-9 +1174 A genotypes were more frequent in TTP patients than in controls (p = 0.04 and p = 0.026, respectively) and more particularly in patients negative for the Class II human leukocyte antigen system susceptibility allele DRB1*11 (p = 0.001 and p = 0.002, respectively). Haplotypes estimation showed that 1174A-2848G haplotype was significantly more frequent in TTP (p = 0.004), suggesting a primary role for this haplotype variation in conferring a predisposition for acquired TTP.


Infections should be considered as an aggravating factor during the course of TTP. Particular polymorphisms in TLR-9 gene may represent risk factors for TTP.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center