Positivity rate of systematic bone marrow smear in patients over 60 years old with newly diagnosed immune thrombocytopenia

Current Concepts in the Diagnosis and Management of Adult Primary Immune Thrombocytopenia: Our Personal View

Primary immune thrombocytopenia (ITP) is an acquired blood disorder that causes a reduction in circulating platelets with the potential for bleeding. The incidence of ITP is slightly higher in adults and affects more women than men until 60 years, when males are more affected. Despite advances in basic science, primary ITP remains a diagnosis of exclusion. The disease is heterogeneous in its clinical behavior and response to treatment. This reflects the complex underlying pathophysiology, which remains ill-understood. Platelet destruction plays a role in thrombocytopenia, but underproduction is also a major contributing factor. Active ITP is a proinflammatory autoimmune disease involving abnormalities within the T and B regulatory cell compartments, along with several other immunological abnormalities. Over the last several years, there has been a shift from using immunosuppressive therapies for ITP towards approved treatments, such as thrombopoietin receptor agonists. The recent COVID-19 pandemic has hastened this management shift, with thrombopoietin receptor agonists becoming the predominant second-line treatment. A greater understanding of the underlying mechanisms has led to the development of several targeted therapies, some of which have been approved, with others still undergoing clinical development. Here we outline our view of the disease, including our opinion about the major diagnostic and therapeutic challenges. We also discuss our management of adult ITP and our placement of the various available therapies.

Older Adults and Immune Thrombocytopenia: Considerations for the Clinician

Many epidemiological studies have shown that the incidence of immune thrombocytopenia (ITP) increases after age 60 years and peaks in patients over age 80 years. Therefore, ITP is a concern for physicians taking care of older patients, especially regarding its diagnosis and management. The diagnostic work-up should exclude other causes of thrombocytopenia and secondary ITP, including myelodysplastic syndrome and drug-induced ITP. The treatment decision is influenced by an increased risk of bleeding, infectious diseases and thrombosis in this population and should take into account comorbidities and concomitant medications such as anticoagulant drugs. First-line treatment is based on short corticosteroids courses and intravenous immunoglobulin, which should be reserved for patients with more severe bleeding complications, with their higher risk of toxic effects as compared with younger patients. Second-line treatment should be tailored to the patient's history, comorbidities and preferences. Preferred second-line treatments are thrombopoietin receptor agonists for most groups and guidelines given their good efficacy/tolerance ratio, but the thrombotic risk is increased in older people. Other second-line options that can be good alternatives depending on the clinical context include rituximab, dapsone, fostamatinib or immunosuppressive drugs. Splenectomy is less often performed but remains an option for fit patients with chronic refractory disease. Emerging treatments such as Syk or Bruton tyrosine kinase inhibitors and FcRn antagonists are becoming available for ITP and may modify the treatment algorithm in the near future. The aim of this review is to describe the particularities of the diagnosis and treatment of ITP in older people, including the response and tolerance to the currently available drugs. We also discuss some situations related to co-morbidities that can frequently lead to adapt the management strategy in older patients.

Frequency and utility of bone marrow examination in relapsed/refractory immune thrombocytopenia

BACKGROUND

The diagnosis of immune thrombocytopenia (ITP) is one of exclusion. Although guidelines recommend against routine bone marrow examination (BME) at time of ITP diagnosis, the role of BME in relapsed/refractory ITP is unclear.

OBJECTIVES

To examine the frequency and predictors of BME in relapsed/refractory ITP.

PATIENTS/METHODS

This multicenter retrospective cohort study included adults with ITP who received second-line therapy in Alberta, Canada from 2012 to 2019. We calculated the frequency of BME and rate of abnormal marrow findings. Logistic regression was performed to assess predictors of BME and predictors of bone marrow pathology.

RESULTS

Of 324 patients with presumed ITP, 181 (56%) underwent BME. We observed a marked decline in the rates of BME among patients >60 years over the past decade, but not in patients younger than age 60 years. On multivariable logistic regression, older age (adjusted OR [aOR] 1.03, p = .0001), anemia (aOR 2.5, p = .01), splenomegaly (aOR 3.2, p = .01), splenectomy (aOR 2.4, p = .02), and lack of splenectomy response (aOR 3.4, p = .04) were significant predictors of BME. Abnormal marrow findings were found in eight (2% of overall cohort; 4% of BME): four myelodysplastic syndrome, one aplastic anemia, one chronic lymphocytic leukemia, one metastatic cancer, and one megaloblastic anemia. Seven (88%) underwent BME for bicytopenias/pancytopenias. Macrocytosis (aOR 9.6, p = .03) and rural residence (aOR 6.7, p = .02) were independent predictors of abnormal bone marrow findings.

CONCLUSIONS

Although routine BME is frequently performed in relapsed/refractory ITP, abnormal findings are rare. Future prospective studies are needed to help identify a subgroup of relapsed/refractory ITP who may benefit from BME.

Incidence of adult primary immune thrombocytopenia in England-An update

BACKGROUND

Adult primary immune thrombocytopenia (ITP) is a rare bleeding disorder of unknown cause. Recent estimates of its incidence and trend over time were acquired for England.

METHOD

The primary ITP population (using ICD 10 code D693 and excluding secondary ITP cases; positive predictive value: 82.6%) was sourced from NHS Digital inpatient and outpatient. Incidence rate (IR) for England and by age groups, sex, and regions were calculated and trends were assessed using average annual percent change (AAPC).

RESULTS

A total of 25 805 patients (mean age 59 years; females 57.8%) diagnosed between 2003 and 2014 was identified. IRs increased from 4.2/100 000 to 6.4/100 000 over this period (AAPC:4.3%). For all sex-specific age groups, the IRs significantly increased over time, except 18-29 years males. The greatest increase was among females aged 30-39 (AAPC:8.7%). In contrast, among ≥70 years, ITP was more common in males (highest IR among ≥80 years males: 23.9/100 000). England's average annual IR was 6.1/100 000 for 2010-14. An estimated 2.5/100 000 (based on UKITP Registry data) was estimated to require 1st line treatment whereas 2.4/100 000 would have 1st and 2nd line treatments within 6 months from diagnosis. IRs for London and East Midlands were the highest (6.5/100 000).

CONCLUSIONS

This study found a rising incidence of primary ITP, with sharp increases among young women and elderly men. These findings put in context the impact of ITP on patients' lives and the healthcare services in England, especially with 17%-50% who may develop chronic ITP and require long-term care.

[Management of multirefractory immune thrombocytopenia]

Multirefractory immune thrombocytopenia (ITP) is defined by the absence of response to TPO receptor agonists, rituximab and splenectomy (or contraindicated or refused) and the need of treatment. The approach to multirefractory ITP must be systematic and firstly involves reconsidering the diagnosis. Inherited thrombocytopenia, lymphoid hemopathies and myelodysplastic syndrome are the main causes to be mentioned. Multirefractory ITP is often associated with secondary ITP with signs of clinical or biological autoimmunity, monoclonal gammopathy of undetermined significance and a poor response to corticosteroids. Therapeutic management is complex and is based on the combination of treatments. New treatments are being developed.