First-LINE Treatment With High-Dose Dexamethasone Terapy For Adult Primary Inmune Thrombocytopenia
Authors: Diaz-Canales Dana , Prieto-Bonilla Maria Rosario , Mingot-Castellano Maria Eva , Heiniger Mazo Ana Isabel 
Published: October 2019

Abstract

Introduction
Primary immune thrombocytopenia (ITP) is an acquired autoimmune disorder with a very variable outcome. Bleeding manifestations and platelets count are considered the main criteria to start treatment in these patients. The initial recommended therapy are corticosteroids and intravenous immunoglobulin (IgsIV). The aim of our study is the description of efficacy and safety of high-dose dexamethasone (Dx) used as frontline therapy in newly diagnosed ITP patients.

Methods
A series of patients diagnosed in our centre from March 2009 to August 2012 has been studied. They have received first-line treatment with Dx (40 mg/d four consecutive days every 2 or 4 weeks) for 1 to 6 courses. Sex, age, cardiovascular risk factors, reasons to treat, response, courses of treatment, complications and relapse rate were recorded and analyzed.

Results
Our series of twenty-nine patients, 18 women (62%) and 11 men (38%), had a median age of 54 years (range 16-92 years). Twenty-five patients (86%) were treated after low platelet counts (30x 10e9 / L) with or without clinical bleeding, whereas the other four patients were treated as a surgery preparation. One patient received a reduced dose of Dx (20 mg/d x 4 days) because of comorbidities and high risk of infection. In thirteen patients, IgsIV were added to Dx in the first course (1g/kg/d x 2 days), because of high bleeding risk or more severe bleeding at diagnosis. Platelets count at baseline was 15x109/ L (range 1-29 x109/ L). Ninety-three percent of patients responded after the first course of Dx (69% complete response CR, 24% partial response PR), and 45% of the patients did not require additional Dx treatment. The median time to reach a response was 5 days since the first day of treatment (range 2-60).
The sixteen patients who need more than one course received a median of 4 (range 2-10), all of them without IgsIV. After a median follow-up of 14 months (range 2-45), 69% of these patients maintained the response without further treatment. Therefore, the overall response of the series reaches 83%.
After 6 courses of treatment, 5 subjects did not achieved response and were classify as corticosteroid dependent. Of these, one patient was splenectomized and at present he remains at CR after 30 months of follow up. Another patient is waiting for splenectomy, and other three received thrombopoietin analogs, remaining all them in CR under treatment.
Thirteen patients received a combination of Igs and Dx in the first course due to high risk of bleeding (platelets less than 20 x 10e9/L and hemorrhagic manifestations). Eleven of them (81%) achieved response (4 PR, 7CR) at a median time of 4 days (range 2–60). After the first course of treatment, 61% (8 of 13) of patients receiving both IgsIV and Dx responded, vs 35% (5 of 16) of those treated only with Dx. This difference was not statistically significant, probably because of the small number of patients in our series. All patients treated with IgsIV and Dx in the first course got the best response after 4 cycles of dexamethasone, compared to 75% of subjects treated with Dx for 4 to 6 courses.
Dx was usually well tolerated, since only 13% of the patients experienced side effects: one case of hypertension, another patient developed hyperglycemia associated to corticosteroids and other two presented mild transient steroid psychosis episodes. Infectious events were not observed.

Conclusions
Treatment with high-dose dexamethasone as first-line treatment for ITP is a good alternative to prednisone because it shows a high efficacy and a good safety profile. In our experience, the association of IgsIV and Dx in the first course may improve the response rate and decrease the total dose of steroids needed to achieve a similar response.

Disclosures:
No relevant conflicts of interest to declare.