Controversias en el tratamiento de la trombocitopenia inmune pediátrica

Diagnostic yield of bone marrow aspiration in paediatric primary immune thrombocytopenia: impact of evolution and adherence to medical guidelines over the last 25 years

The aim of this study is to analyse the diagnostic value of bone marrow aspiration (BMA) in a retrospective cohort of patients with suspected immune thrombocytopaenia (ITP). We further measure changes in the percentage of patients who underwent this study and whether testing or not was in accordance with current guidelines at the time of diagnosis. We conducted a chart review of 243 patients with ITP who underwent follow-up in our institution between 1995 and 2022. The patients were divided into historical cohorts based on the practice guidelines of the Spanish Society of Pediatric Hematology and Oncology (SEHOP) and the American Society of Hematology (ASH) in place at the time of follow-up. For each case, time of disease presentation or initial diagnosis was defined as that which occurred in the first 72 h following disease onset. Based on data from the historical cohorts studied, we observed a lower total number of BMAs at diagnosis over time (p < 0.005). A gradual reduction was seen in the number of BMAs with the introduction of guidelines, including a progressively lower number of BMAs performed without indication (p < 0.05). Subsequent to the initial diagnosis, the procedure played a decisive role in only 2 patients (0.58%), allowing for a diagnosis of acquired aplastic anaemia in both cases. In both of them on diagnosis, BMA did not appear to be indicated, although subsequent analysis after 72 h raised suspicion of bone marrow failure.

CONCLUSION

BMA at presentation did not significantly alter the diagnosis in our cohort of patients with an initial suspicion of ITP, although the procedure was decisive in diagnosing 2 cases of acquired aplastic anaemia during the subsequent course of the disease. Regarding the number of aspirations performed, our findings show that increased physician compliance with current guidelines reduced the rate of unnecessary BMAs.

WHAT IS KNOWN

• BMA is a supplementary test for the diagnosis of ITP. • The usefulness of this invasive diagnostic procedure is not clearly stated in current guidelines.

WHAT IS NEW

• Adjustments to scientific guidelines have led to a reduction in the number of BMAs performed on our patients with suspected ITP in the last 27 years. • While the risks and benefits of BMA at the time of diagnosis are unclear in patients with suspected ITP, the procedure does not contribute significant information to support the diagnosis.

Mycophenolate mofetil for autoimmune cytopenias in children: high rates of response in inborn errors of immunity

Second-line treatments of autoimmune cytopenias (AC) are not well-defined in children. Mycophenolate mofetil (MMF) is an immunosuppressant agent that has been demonstrated to be safe and effective in this setting. A retrospective observational study was conducted in 18 children with prolonged AC who received MMF, in order to describe clinical and biological markers of response. The overall response rate of MMF at 20-30 mg/kg per day was 73.3%. All patients with Evans syndrome (n = 9) achieved complete response. Among the patients with monolineage AC (n = 9), those with an underlying inborn errors of immunity (IEI), tended to respond better to MMF. No biological markers related to treatment response were found. Rather, lymphocyte subpopulations proved useful for patient selection as a marker suggestive of IEI along with immunoglobulin-level determination.

Outcomes of switching to avatrombopag following treatment failure with eltrombopag in paediatric immune thrombocytopenia: A real-world study in China

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder characterized by isolated thrombocytopenia and a haemorrhagic risk. Thrombopoietin receptor agonists (TPO-RAs) are highly effective for ITP and are widely used to treat patients with steroid treatment failure or dependency. However, although treatment response to TPO-RAs may differ according to the type, the potential impact of switching from eltrombopag (ELT) to avatrombopag (AVA) with respect to efficacy or tolerance in children remains unknown. This study aimed to evaluate the outcomes of switching from ELT to AVA in paediatric patients with ITP. We retrospectively evaluated children with chronic immune thrombocytopenia (cITP) switched from ELT to AVA owing to treatment failure at the Hematology-Oncology Center of Beijing Children's Hospital between July 2021 and May 2022. Overall, 11 children (seven and four boys and girls respectively) with a median age of 8.3 (range: 3.8-15.3) years were included. The overall response and complete response (platelet [PLT] count ≥100 × 10⁹ /L) rates during AVA treatment were 81.8% (9/11) and 54.6% (6/11) respectively. The median PLT count was significantly increased from ELT to AVA (7 [range: 2-33] × 10⁹ /L vs. 74 [15-387] × 10⁹ /L; p = 0.007). The median time to PLT count ≥30 × 10⁹ /L was 18 (range: 3-120) days. Overall, 7/11 patients (63.6%) used concomitant medications, and concomitant medication use was gradually discontinued within 3-6 months after AVA initiation. In conclusion, AVA after ELT is effective in the heavily pretreated paediatric cITP population, with high response rates even in those with an inadequate response to a prior TPO-RA.

Secondary immune thrombocytopenia in children: Characteristics and outcome of a large cohort from two Spanish centres

AIM

To evaluate the incidence and outcome of secondary immune thrombocytopenia (ITP) in a large cohort of paediatric Spanish patients.

METHODS

A retrospective observational study was conducted in two paediatric University hospitals in Spain between 2009 and 2019, which included children from 4 months to 18 years old diagnosed with ITP. Data were recorded from clinical charts: gender, age at diagnosis, coexisting condition and associated characteristics, outcome and treatment.

RESULTS

Secondary ITP was diagnosed in 87 out of 442 patients (19.6%). Post-immunisation ITP was seen in younger children. The onset of secondary ITP to autoimmune diseases (AD) and immunodeficiencies (ID) was at an older age and had more tendency to be insidious, and platelet level was higher than primary ITP. Mean time from ITP onset to AD diseases or ID diagnosis was 1.2 and 2.6 years, respectively. Whereas the cumulative incidence of remission was significantly higher in post-immunisation and post-viral infection (compared with primary ITP patients), it was worse in AD and ID patients.

CONCLUSIONS

Identification of secondary ITP is important as it predicts outcome. Most of them are diagnosed at ITP onset, but AD diseases and ID should be ruled out periodically as they are usually identified later.

Efficacy and safety of eltrombopag in the treatment of Chinese children with chronic immune thrombocytopenia

OBJECTIVES

Our aim is to evaluate initial efficacy, safety, and durable response of eltrombopag in the treatment of Chinese children with chronic immune thrombocytopenia (cITP).

METHODS

This was a retrospective, single-center cohort study including 30 pediatric patients with cITP administered eltrombopag between 1 July 2017 and 1 January 2019. Patients with at least 12 weeks of eltrombopag treatment and available follow-up data were included. Initial response rate, durable response rate, bleeding events, and adverse events were assessed during the follow-up period.

RESULTS

The median duration of eltrombopag administration was 6 months (range 3-8 months). The initial response rate was 73.3%. Patients with megakaryocyte count ≥100/slide or Treg <4.5% were more likely to achieve initial response. The median follow-up period was 10 months (range 6-20 months). A total of 53.2% of pediatric patients had a durable response of up to 20 months. Patients with megakaryocyte count ≥100/slide and Treg<4.5% had more than 60% durable response rates compared with individuals with megakaryocyte count<100/slide and Treg≥4.5%, respectively. No serious bleeding events or serious adverse events occurred during the study period.

CONCLUSION

Eltrombopag not only shows excellent initial response but also has continued efficacy and safety. Patients with megakaryocyte count ≥100/slide and Treg<4.5% achieve increased initial response and more frequent durable response.