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1.
Am J Hematol ; 94(12): 1314-1324, 2019 12.
Article in English | MEDLINE | ID: mdl-31489694

ABSTRACT

Rituximab is a second-line option in adults with immune thrombocytopenia (ITP), but the estimated 5-year response rate, only based on pooled retrospective data, is about 20%, and no studies have focused on long-term safety. We conducted a prospective multicenter registry of 248 adults with ITP treated with rituximab with 5 years of follow-up to assess its long-term safety and efficacy. The median follow-up was 68.4 [53.7-78.5] months. The incidence of severe infections was only 2/100 patient-years. Profound hypogammaglobulinemia (<5 g/L) developed in five patients at 15 to 31 months after the last rituximab infusion. In total, 25 patients died at a median age of 80 [69.5-83.9] years, corresponding to a mortality rate of 2.3/100 patient-years. Only three deaths related to infection that occurred 12 to 14 months after rituximab infusions could be due in part to rituximab. At 60 months of follow-up, 73 (29.4%) patients had a sustained response. On univariate and multivariate analysis, the only factor significantly associated with sustained response was a previous transient response to corticosteroids (P = .022). Overall, 24 patients with an initial response and then relapse received retreatment with rituximab, which gave a response in 92%, with a higher duration of response in 54%. As a result of its safety profile and its sustained response rate, rituximab remains an important option in the current therapeutic armamentarium for adult ITP. Retreatment could be an effective and safe option.


Subject(s)
Purpura, Thrombocytopenic, Idiopathic/drug therapy , Rituximab/therapeutic use , Adrenal Cortex Hormones/therapeutic use , Adult , Agammaglobulinemia/chemically induced , Agammaglobulinemia/epidemiology , Aged , Aged, 80 and over , Autoimmune Diseases/epidemiology , Autoimmune Diseases/etiology , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/etiology , Cause of Death , Disease-Free Survival , Drug Eruptions/epidemiology , Drug Eruptions/etiology , Drug Substitution , Female , Follow-Up Studies , France/epidemiology , Humans , Infections/epidemiology , Male , Middle Aged , Neoplasms/epidemiology , Neoplasms/etiology , Neoplasms/immunology , Pregnancy , Pregnancy Complications/epidemiology , Pregnancy Outcome , Prospective Studies , Purpura, Thrombocytopenic, Idiopathic/mortality , Registries , Rituximab/adverse effects , Serum Sickness/chemically induced , Serum Sickness/epidemiology
2.
Thromb Haemost ; 119(3): 384-396, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30650444

ABSTRACT

In obesity, platelets are described as hyperactive, mainly based on increased platelet size and presence of pro-thrombotic plasmatic molecules. We explored platelet functions, including calcium signalling in obesity, and the effect of weight loss. We included 40 obese patients (women with body mass index [BMI] of ≥ 35 kg/m2) who were to undergo gastric bypass surgery and 40 healthy lean subjects (women with BMI of < 25 kg/m2) as a control group. Approximately 1 year after surgery, the obese patients lost weight (75% had a BMI < 35 kg/m2). They were explored a second time with the same healthy control for the same platelet experiments. Compared with controls, obese patients' platelets displayed reduced sensitivity to thrombin (aggregation EC50 increased by 1.9 ± 0.3-fold, p = 0.005) and a lower Ca2+ response (70 ± 7% decrease, p < 10-4). In 17 pairs of patients, we performed additional experiments: in obese patients' platelets, thrombin-induced αIIbß3 activation was significantly lower (p = 0.003) and sarco-endoplasmic reticulum Ca2+ATPase (SERCA3) expression was decreased (48 ± 6% decrease, p < 10-4). These differences were abolished after weight loss. Interestingly, pharmacological inhibition of SERCA3 activity in control group's platelets mimicked similar alterations than in obese patients' platelets and was associated with defective adenosine diphosphate (ADP) secretion. Addition of ADP to agonist restored platelet functions in obese patients and in SERCA3-inhibited control platelets (five experiments) confirming the direct involvement of the SERCA3-dependent ADP secretion pathway. This is the first study demonstrating that platelets from obese patients are hypo-reactive, due to a deficiency of SERCA3-dependent ADP secretion. Weight loss restores SERCA3 activity and subsequent calcium signalling, αIIbß3 activation, platelet aggregation and ADP secretion.


Subject(s)
Adenosine Diphosphate/blood , Blood Platelets/metabolism , Gastric Bypass , Obesity/surgery , Platelet Activation , Sarcoplasmic Reticulum Calcium-Transporting ATPases/blood , Weight Loss , Adult , Calcium Signaling , Female , Humans , Obesity/blood , Obesity/diagnosis , Obesity/physiopathology , Paris , Platelet Aggregation , Platelet Function Tests , Platelet Glycoprotein GPIIb-IIIa Complex/metabolism , Secretory Pathway , Time Factors , Treatment Outcome
4.
Blood ; 124(22): 3228-36, 2014 Nov 20.
Article in English | MEDLINE | ID: mdl-25293768

ABSTRACT

We conducted a prospective multicenter registry of 248 adult patients with immune thrombocytopenia (ITP) treated with rituximab to assess safety. We also assessed response and predictive factors of sustained response. In total, 173 patients received 4 infusions of 375 mg/m(2) and 72 received 2 fixed 1-g infusions 2 weeks apart. The choice of the rituximab regimen was based on the physician's preference and not patient characteristics. Overall, 38 patients showed minor intolerance to rituximab infusions; infusions had to be stopped for only 3 patients. Seven showed infection (n = 11 cases), with an incidence of 2.3 infections/100 patient-years. Three patients died of infection 12 to 14 months after rituximab infusions, but the role of rituximab was questionable. In total, 152 patients (61%) showed an overall initial response (platelet count ≥30 × 10(9)/L and ≥2 baseline value). At a median follow-up of 24 months, 96 patients (39%) showed a lasting response. On multivariate analysis, the probability of sustained response at 1 year was significantly associated with ITP duration <1 year (P = .02) and previous transient complete response to corticosteroids (P = .05). The pattern of response was similar with the 2 rituximab regimens. With its benefit/risk ratio, rituximab used off-label may remain a valid option for treating persistent or chronic ITP in adults. This trial was registered at www.clinicaltrials.gov as #NC1101295.


Subject(s)
Antibodies, Monoclonal, Murine-Derived/therapeutic use , Purpura, Thrombocytopenic, Idiopathic/drug therapy , Adult , Aged , Antibodies, Monoclonal, Murine-Derived/adverse effects , Cause of Death , Disease-Free Survival , Female , Humans , Male , Middle Aged , Prospective Studies , Purpura, Thrombocytopenic, Idiopathic/epidemiology , Recurrence , Registries , Rituximab , Treatment Outcome
5.
Ann Biol Clin (Paris) ; 71(4): 481-4, 2013.
Article in French | MEDLINE | ID: mdl-23906580

ABSTRACT

A 58-year-old patient, without any notable medical history, except for alcoholism and treated hypertension, developed anemia and leukopenia with macrocytosis. Folate deficiency was diagnosed and subsequently treated. Despite folate supplementation, the hematological parameters did not normalize. Further diagnosis investigations were led to search for uncommon etiologies of anemia and leukoneutropenia. We diagnosed severe copper deficiency on the basis of decreased plasma levels of copper and ceruloplasmin. Copper supplementation improved blood counts within three months. This case illustrates hematological disorders due to copper deficiency, initially masked by an associated folate deficiency. The copper deficiency etiology was not identified in this case.


Subject(s)
Anemia, Macrocytic/etiology , Copper/deficiency , Alcoholism/complications , Ceruloplasmin/deficiency , Copper/blood , Diagnosis, Differential , Folic Acid Deficiency/complications , Folic Acid Deficiency/drug therapy , Follow-Up Studies , Humans , Hypertension/drug therapy , Leukopenia/etiology , Male , Middle Aged
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