Screening of Corticosteroid-Induced Osteoporosis in Patients with Immune Thrombocytopenia or Warm Autoimmune Hemolytic Anemia in the Outpatient Setting

Introduction:

Corticosteroids (CS) are the standard first line treatment for immune thrombocytopenia (ITP) and warm autoimmune hemolytic anemia (WAIHA). Current guidelines advise against long-term CS (LTCS) use to minimize associated toxicities. Despite these guidelines, a number of patients remain on LTCS. For example, in a retrospective study of 53 patients with WAIHA, the mean duration of CS therapy was 15 months (mo) with 20% of patients with CS-induced diabetes, 10% with worsening of pre-existing diabetes, 10% with osteoporosis (OP) with fracture, and 4% with osteonecrosis of the femoral head (Roumier 2014).

It is our observation that our hematology clinic patients may benefit from the application of guidelines for the prevention of CS-induced OP. The 2017 American College of Rheumatology (ACR) guidelines for prevention and treatment of CS-induced OP include a baseline clinical fracture risk assessment within 6 mo of the start of LTCS therapy (≥3 mo) followed by age and risk-adapted OP screening (Buckley 2017). Adults <40 years old (yo) with OP risk factors or prior OP fracture should undergo baseline bone mineral density (BMD) testing within 6 months of the start of CS therapy. For patients ≥40 yo, the Fracture Risk Assessment Tool (FRAX) with CS dose correction and BMD testing should be done within 6 mo of the start of CS therapy. With no similar national hematology guidelines, we applied 2017 American College of Rheumatology (ACR) guidelines for the prevention of CS-induced OP to our hematology clinic patients. The aim of the study was to improve screening for CS-induced OP in patients with ITP or WAIHA.

Methods:

We retrospectively identified patients with ITP or WAIHA by ICD-10 codes who were seen in the hematology clinic at LAC+USC Medical Center, Los Angeles, CA, from October 1, 2020 to March 31, 2021. The electronic medical record (EMR) was reviewed for demographic data and to confirm diagnosis. The relevant clinical history including CS dose/duration, common adverse events (AEs) from LTCS use, and BMD screening with a dual-energy X-ray absorptiometry (DEXA) scan. The patients were assessed for whether they underwent appropriate screening for CS-induced OP based on ACR guidelines.

Results:

Of the 2256 patient encounters in the hematology clinic during the 6-mo study period, 54 patients were identified with either ITP and/or WAIHA. The median age was 49 yo (range: 21-87), 74% were female (40/54) and 85.2% (46/54) were Hispanic. Of these 54 patients, 46 patients had prior or current CS therapy with either prednisone or dexamethasone. The most common AEs associated with CS included: weight gain (34.8%, 16/54), hypertriglyceridemia (34.8%, 16/54), worsening of diabetes (7.4%, 4/54), and worsening hypertension (3.7%, 2/54). Of the 15 patients <40 yo, 7 received LTCS therapy for ≥3 months and 42.9% (3/7) underwent screening with a DEXA scan. 1 had a normal BMD, 1 had osteopenia and 1 had OP. Of the 39 patients ≥40 years, 14 had received LTCS therapy for ≥3 months and 14.3% (2/14) had a screening DEXA scan; both demonstrated osteopenia. 2 patients with <3 months of CS therapy underwent screening - 1 for CS use, which showed osteopenia and one for age-appropriate screening of OP, which also showed osteopenia. Of the 6 patients with osteopenia or OP, 83.3% (5/6) were on vitamin D and calcium supplementation prior to screening. After diagnosis of osteopenia, one patient was not started on vitamin D and calcium supplementation. Bisphosphate therapy was initiated after diagnosis of OP in 1 patient.

Conclusions:

The majority of patients with ITP or WAIHA seen in our hematology clinic who were treated with LTCS ≥3 months did not receive a screening DEXA scan for OP as recommended by ACR guidelines. With this baseline data, we propose a quality improvement initiative in our clinic to ensure that all patients on LTCS are assessed for OP risk. Planned interventions include resident/fellow education, creation of a handout of the ACR guidelines posted in clinic, implementation of clinical fracture risk reassessment at baseline and every 12 months with BMD as indicated, and implementation of an EMR template to ensure uniform documentation. More broadly, our findings serve as a reminder of the importance for monitoring CS duration and suggest a need for a structured approach to monitoring for short and long-term toxicities of CS for the field of hematology. The creation of hematology-specific guidelines may be beneficial in this effort.