Diagnosis and management of chronic and refractory immune cytopenias in children, adolescents, and young adults

Egyptian Pediatric Guidelines for the Management of Children with Isolated Thrombocytopenia Using the Adapted ADAPTE Methodology-A Limited-Resource Country Perspective

BACKGROUND

Thrombocytopenia is a prevalent presentation in childhood with a broad spectrum of etiologies, associated findings, and clinical outcomes. Establishing the cause of thrombocytopenia and its proper management have obvious clinical repercussions but may be challenging. This article provides an adaptation of the high-quality Clinical Practice Guidelines (CPGs) of pediatric thrombocytopenia management to suit Egypt's health care context.

METHODS

The Adapted ADAPTE methodology was used to identify the high-quality CPGs published between 2010 and 2020. An expert panel screened, assessed and reviewed the CPGs and formulated the adapted consensus recommendations based on the best available evidence.

DISCUSSION

The final CPG document provides consensus recommendations and implementation tools on the management of isolated thrombocytopenia in children and adolescents in Egypt. There is a scarcity of evidence to support recommendations for various management protocols. In general, complete clinical assessment, full blood count, and expert analysis of the peripheral blood smear are indicated at initial diagnosis to confirm a bleeding disorder, exclude secondary causes of thrombocytopenia and choose the type of work up required. The International Society of Hemostasis and thrombosis-Bleeding assessment tool (ISTH-SCC BAT) could be used for initial screening of bleeding manifestations. The diagnosis of immune thrombocytopenic purpura (ITP) is based principally on the exclusion of other causes of isolated thrombocytopenia. Future research should report the outcome of this adapted guideline and include cost-analysis evaluations.

Primary immune thrombocytopenia: a 'diagnosis of exclusion'?

Current diagnosis of primary immune thrombocytopenia (ITP) is presumptive, centered on excluding other causes of thrombocytopenia. The diagnosis of ITP is challenging because of the wide range of potential inherited and acquired causes of thrombocytopenia. The treatment of ITP is empiric with steroids, high-dose immunoglobulin, immunosuppressants and thrombopoietin agonists with potential side effects. We searched Medline and Cochrane databases, reviewed the study data and analyzed the individual diagnostic tests for their evidence-based role in the diagnosis of ITP. We then analyzed the strength of the scientific evidence for each diagnostic test in the diagnosis of ITP and identified gaps in the diagnostic accuracy. The diagnostic challenges in ITP include: insufficient evidence for the individual test for diagnosis of ITP, no standardized protocol/guideline for diagnosis, hurdles in accessing the available resources and failure to correlate the clinical data while reviewing the blood smear. We did not identify a diagnostic test that clinicians can use to confirm the diagnosis of ITP. In the absence of a diagnostic test of proven value in ITP, the clinician is best served by a comprehensive history and physical examination, complete blood count and review of the peripheral blood smear in evaluating thrombocytopenia.

Peripheral‐blood cytopenia, an early indicator of inborn errors of immunity

Inborn errors of immunity (IEI) are inherited monogenic disorders resulting in defective immune response. Non‐infectious presentations are increasingly more apparent. Widely available, cost‐effective early indicators are needed. Peripheral‐blood cytopenia may be a presenting laboratory feature or an observed secondary phenomenon. This retrospective review of the South African Primary Immunodeficiency Registry (SAPIDR) aimed to assess the haematological indices at presentation and their association with the International Union of Immunological Societies (IUIS) 2019 IEI classification and mortality. Of 396 patients on the SAPIDR, 66% (n = 257) had available haematological results. Sixty percent were males and 85% under 18 years. A majority (53%) had predominantly antibody deficiency. At presentation, infection was prominent (86%) followed by cytopenia (62%). Neutropenia was associated with IUIS III [odds ratio (OR) 3.65, confidence interval (CI) 1.44–9.25], thrombocytopenia with IUIS II (OR 14.39, CI 2.89–71.57), lymphopenia with IUIS I (OR 12.16, CI 2.75–53.73) and pancytopenia with IUSI I (OR 12.24, CI 3.82–39.05) and IUIS II (OR 5.99, CI 2.80–12.76). Cytopenia showed shorter overall survival (OR 2.81, CI 1.288–4.16). Cytopenias that are severe, persistent, unusual and/or recurrent should prompt further investigation for IEI. The full blood count and leucocyte differential may facilitate earlier identification and serve as an adjunct to definitive molecular classification.

Pathogenesis of Autoimmune Cytopenias in Inborn Errors of Immunity Revealing Novel Therapeutic Targets

Autoimmune diseases are usually associated with environmental triggers and genetic predisposition. However, a few number of autoimmune diseases has a monogenic cause, mostly in children. These diseases may be the expression, isolated or associated with other symptoms, of an underlying inborn error of immunity (IEI). Autoimmune cytopenias (AICs), including immune thrombocytopenic purpura (ITP), autoimmune hemolytic anemia (AIHA), autoimmune neutropenia (AN), and Evans’ syndrome (ES) are common presentations of immunological diseases in the pediatric age, with at least 65% of cases of ES genetically determined. Autoimmune cytopenias in IEI have often a more severe, chronic, and relapsing course. Treatment refractoriness also characterizes autoimmune cytopenia with a monogenic cause, such as IEI. The mechanisms underlying autoimmune cytopenias in IEI include cellular or humoral autoimmunity, immune dysregulation in cases of hemophagocytosis or lymphoproliferation with or without splenic sequestration, bone marrow failure, myelodysplasia, or secondary myelosuppression. Genetic characterization of autoimmune cytopenias is of fundamental importance as an early diagnosis improves the outcome and allows the setting up of a targeted therapy, such as CTLA-4 IgG fusion protein (Abatacept), small molecule inhibitors (JAK-inhibitors), or gene therapy. Currently, gene therapy represents one of the most attractive targeted therapeutic approaches to treat selected inborn errors of immunity. Even in the absence of specific targeted therapies, however, whole exome genetic testing (WES) for children with chronic multilineage cytopenias should be considered as an early diagnostic tool for disease diagnosis and genetic counseling.

Autoimmune hemolytic anemia in children: Clinical presentation and treatment outcome

BACKGROUND

Autoimmune hemolytic anemias (AIHA) are characterized by the destruction of red cells following the production of autoantibodies directed against them. Although AIHA in children is usually self-limiting, many still succumb to the illness due to delay in the diagnosis and treatment. AIHA in children may be secondary to autoimmune diseases, drugs, or immune deficiencies. Early diagnosis and appropriate immunohematological evaluation can aid in the diagnosis and treatment.

OBJECTIVE

To analyze the evaluation, treatment, and outcome of AIHA in children.

METHODS

Prospective data of patients aged 0-18 years diagnosed with AIHA between June 2017 and May 2019 were collected.

INTERVENTION

Prednisolone was the first-line agent in all; second-line agents included cyclosporine and rituximab. Red cell transfusion was given in those with severe anemia with cardiac decompensation.

RESULTS

Eleven patients were diagnosed during the study period. Hemoglobin ranged from 1.2 to 9 g/dl. The initial presentation was severe anemia in 8 children and moderate anemia with thrombocytopenia in 3. The trigger was infection in 5. Polyspecific direct coomb's test (DCT) was positive in 10 patients. 2/10 polyspecific DCT-positive cases on further evaluation had immunoglobulin G (IgG) and C3d positivity, whereas rest 8 had only IgG. One infant was diagnosed with DCT-negative immunoglobulin A-mediated AIHA. 4/11 attained remission following the short course of prednisolone. Cyclosporine was used as the second-line agent in 2 and rituximab was used in 3. Seven children are in sustained remission and off medication. One died within 12 h of diagnosis.

CONCLUSION

AIHA is not an uncommon problem in children and can vary in its clinical severity. Early and correct diagnosis helps in deciding appropriate treatment.

Misdiagnosed thrombocytopenia in children and adolescents: analysis of the Pediatric and Adult Registry on Chronic ITP

Primary immune thrombocytopenia (ITP) in children is a diagnosis of exclusion, but cases of secondary ITP and nonimmune thrombocytopenia (non-IT) are generally difficult to recognize in a timely fashion. We describe a pediatric population with a revised diagnosis of secondary ITP or non-IT within 24 months of follow-up. Data were extracted from the Pediatric and Adult Registry on Chronic ITP, an international multicenter registry collecting data prospectively in patients with newly diagnosed primary ITP. Between 2004 and 2019, a total of 3974 children aged 3 months to 16 years were included. Secondary ITP and non-IT were reported in 113 patients (63 female subjects). Infectious (n = 53) and autoimmune (n = 42) diseases were identified as the main causes, with median ages at diagnosis of 3.2 years (interquartile range: 1.2; 6.7 years) and 12.4 years (interquartile range: 7.6; 13.7 years), respectively. Other causes included malignancies, aplastic anemia, immunodeficiency, and drug use. Patients with malignancy and aplastic anemia had significantly higher initial platelet counts (37 and 52 × 109/L) than did those with infection or autoimmune diseases (12 and 13 × 109/L). Characteristics of patients with secondary ITP due to infection were similar to those of children with primary ITP at first presentation, indicating similar mechanisms. Significant differences were found for age, sex, comorbidities, initial bleeding, sustained need for treatment, and disease persistence for the remaining noninfectious group compared with primary ITP. Based on our findings, we propose a diagnostic algorithm that may serve as a basis for further discussion and prospective trials.

Primary Immunodeficiency in Children With Autoimmune Cytopenias: Retrospective 154-Patient Cohort

Background

Primary immunodeficiency is common among patients with autoimmune cytopenia.

Objective

The purpose of this study is to retrospectively identify key clinical features and biomarkers of primary immunodeficiency (PID) in pediatric patients with autoimmune cytopenias (AIC) so as to facilitate early diagnosis and targeted therapy.

Methods

Electronic medical records at a pediatric tertiary care center were reviewed. We selected 154 patients with both AIC and PID (n=17), or AIC alone (n=137) for inclusion in two cohorts. Immunoglobulin levels, vaccine titers, lymphocyte subsets (T, B and NK cells), autoantibodies, clinical characteristics, and response to treatment were recorded.

Results

Clinical features associated with AIC-PID included splenomegaly, short stature, and recurrent or chronic infections. PID patients were more likely to have autoimmune hemolytic anemia (AIHA) or Evans syndrome than AIC-only patients. The AIC-PID group was also distinguished by low T cells (CD3 and CD8), low immunoglobulins (IgG and IgA), and higher prevalence of autoantibodies to red blood cells, platelets or neutrophils. AIC diagnosis preceded PID diagnosis by 3 years on average, except among those with partial DiGeorge syndrome. AIC-PID patients were more likely to fail first-line treatment.

Conclusions

AIC patients, especially those with Evans syndrome or AIHA, should be evaluated for PID. Lymphocyte subsets and immune globulins serve as a rapid screen for underlying PID. Early detection of patients with comorbid PID and AIC may improve treatment outcomes. Prospective studies are needed to confirm the diagnostic clues identified and to guide targeted therapy.

Immune cytopenias as a continuum in inborn errors of immunity: An in-depth clinical and immunological exploration

BACKGROUND

Immune thrombocytopenia (ITP), autoimmune hemolytic anemia (AIHA), and autoimmune neutropenia (AIN) are disorders characterized by immune-mediated destruction of hematopoietic cell lineages. A link between pediatric immune cytopenias and inborn errors of immunity (IEI) was established in particular in the combined and chronic forms.

OBJECTIVE

Aim of this study is to provide clinical-immunological parameters to hematologists useful for a prompt identification of children with immune cytopenias deserving a deeper immunological and genetic evaluation.

METHODS

We retrospectively collected 47 pediatric patients with at least one hematological disorder among which persistent/chronic ITP, AIHA, and AIN, aged 0-18 years at onset of immune cytopenias and/or immune-dysregulation. The cohort was divided into two groups (IEI+ and IEI-), based on the presence/absence of underlying IEI diagnosis. IEI+ group, formed by 19/47 individuals, included: common variable immune deficiency (CVID; 9/19), autoimmune lymphoproliferative syndrome (ALPS; 4/19), DiGeorge syndrome (1/19), and unclassified IEI (5/19).

RESULTS

IEI prevalence among patients with ITP, AIHA, AIN, and Evans Syndrome was respectively of 42%, 64%, 36%, and 62%. In IEI+ group the extended immunophenotyping identified the presence of statistically significant (p < .05) specific characteristics, namely T/B lymphopenia, decrease in naїve T-cells%, switched memory B-cells%, plasmablasts%, and/or immunoglobulins, increase in effector/central memory T-cells% and CD21low B-cells%. Except for DiGeorge and three ALPS patients, only 2/9 CVID patients had a molecular diagnosis for IEI: one carrying the pathogenic variant CR2:c.826delT, the likely pathogenic variant PRF1:c.272C> and the compound heterozygous TNFRSF13B variants p.Ser144Ter (pathogenic) and p.Cys193Arg (variant of uncertain significance), the other one carrying the likely pathogenic monoallelic variant TNFRSF13B:p.Ile87Asn.

CONCLUSION

The synergy between hematologists and immunologists can improve and fasten diagnosis and management of patients with immune cytopenias through a wide focused clinical/immunophenotypical characterization, which identifies children worthy of IEI-related molecular analysis, favouring a genetic IEI diagnosis and potentially unveiling new targeted-gene variants responsible for IEI phenotype.

Treatment of immune-mediated cytopenias in patients with primary immunodeficiencies and immune regulatory disorders (PIRDs)

Severe immune cytopenias (SICs) are rare acquired conditions characterized by immune-mediated blood cell destruction. They may necessitate emergency medical management and long-term immunosuppressive therapy, strongly compromising the quality of life. The initial diagnostic workup involves excluding malignancies, congenital cytopenias, bone marrow failure syndromes, infections, and rheumatologic diseases such as systemic lupus erythematosus. Causal factors for SIC such as primary immunodeficiencies or immune regulatory disorders, which are referred to as inborn errors of immunity (IEIs), should be diagnosed as early as possible to allow the initiation of a targeted therapy and avoid multiple lines of ineffective treatment. Ideally, this therapy is directed against an overexpressed or overactive gene product or substitutes a defective protein, restoring the impaired pathway; it can also act indirectly, enhancing a countermechanism against the disease-causing defect. Ultimately, the diagnosis of an underling IEI in patients with refractory SIC may lead to evaluation for hematopoietic stem cell transplantation or gene therapy as a definitive treatment. Interdisciplinary care is highly recommended in this complex patient cohort. This case-based educational review supports decision making for patients with immune-mediated cytopenias and suspected inborn errors of immunity.

Evans' Syndrome: From Diagnosis to Treatment

Evans' syndrome (ES) is defined as the concomitant or sequential association of warm auto-immune haemolytic anaemia (AIHA) with immune thrombocytopenia (ITP), and less frequently autoimmune neutropenia. ES is a rare situation that represents up to 7% of AIHA and around 2% of ITP. When AIHA and ITP occurred concomitantly, the diagnosis procedure must rule out differential diagnoses such as thrombotic microangiopathies, anaemia due to bleedings complicating ITP, vitamin deficiencies, myelodysplastic syndromes, paroxysmal nocturnal haemoglobinuria, or specific conditions like HELLP when occurring during pregnancy. As for isolated auto-immune cytopenia (AIC), the determination of the primary or secondary nature of ES is important. Indeed, the association of ES with other diseases such as haematological malignancies, systemic lupus erythematosus, infections, or primary immune deficiencies can interfere with its management or alter its prognosis. Due to the rarity of the disease, the treatment of ES is mostly extrapolated from what is recommended for isolated AIC and mostly relies on corticosteroids, rituximab, splenectomy, and supportive therapies. The place for thrombopoietin receptor agonists, erythropoietin, immunosuppressants, haematopoietic cell transplantation, and thromboprophylaxis is also discussed in this review. Despite continuous progress in the management of AIC and a gradual increase in ES survival, the mortality due to ES remains higher than the ones of isolated AIC, supporting the need for an improvement in ES management.

Successful Treatment of an Adolescent Male With Severe Refractory Evans Syndrome Using Bortezomib-based Therapy

Evans syndrome is defined by bilineal autoimmune cytopenia, typically coombs positive hemolytic anemia and thrombocytopenia. Corticosteroids are the mainstay of treatment, with rituximab and/or mycophenolate mofetil often used in steroid-refractory cases. However, no treatment methodology has ever evaluated by a randomized clinical trial. We present a 15-year-old boy with Evans syndrome and common variable immunodeficiency who experienced a severe, refractory flare 16 months postsplenectomy. After failing to respond to multiple other agents, he achieved a durable response to a bortezomib-based regimen. Bortezomib may be a reasonable second or third line option, especially before high-morbidity therapies such as splenectomy or stem cell transplantation.

Evans Syndrome in Childhood: Long Term Follow-Up and the Evolution in Primary Immunodeficiency or Rheumatological Disease

Evans syndrome (ES) is a rare but challenging condition, characterized by recurrent and refractory cytopenia episodes. Recent discoveries highlighted that an appropriate diagnostic workup is fundamental to identify an underlying immune dysregulation such as primary immunodeficiencies or a rheumatological disease. We hereby describe clinical features and laboratory results of 12 pediatric patients affected by ES referred to the Pediatric Onco-Hematology Unit of Bologna. Patients experienced a median of four acute episodes of cytopenia with 9 years as median age at the onset of symptoms. In 8/12 (67%) patients an underlying etiology, primary immunodeficiencies, or rheumatological disease was identified. In 4/12 children, other immune manifestations were associated (Thyroiditis, Celiac disease, Psoriasis, Vitiligo, Myositis, Membranoproliferative Glomerulonephritis). ES remained the primary diagnosis in four patients (33%). At a median follow-up time of 4 years, 5/12 (42%) patients revealed a chronic ITP, partially responsive to second line therapy. Immunoglobulin Replacement Therapy (IRT) was effective with a good hematological values control in three patients with a secondary ES (ALPS, CVID, and a patient with Rubinstein Taybi Syndrome and a progressive severe B cell deficiency with hypogammaglobulinemia). Our experience highlights that, in pediatric patients, ES is often only the first manifestation of an immunological or rheumatological disease, especially when cytopenias are persistent or resistant to therapy, with an early-onset or when are associated with lymphadenopathy.

Ethical conundrums in pediatric genomics

Recent genomic discoveries have improved our understanding of many hematologic diseases and led to novel therapeutic options for many patients. The rapid decrease in the cost of genomic testing has enabled widespread use of clinical genomic testing. However, these advances are accompanied by concomitant challenging ethical concerns. In pediatrics, issues of informed consent for genomic testing, assent, and permission vary significantly by patient age and comprehension. Broader testing strategies, such as whole-exome or whole-genome sequencing, are more likely to yield incidental findings unrelated to the reason for the initial test, and plans to deal with these results when they occur are increasingly important. The lines of clinical care and research are becoming more blurry in the era of precision medicine in which approaches to individual genetic mutations (as opposed to disease phenotypes) occur with increased frequency. Finally, because justice is a fundamental ethical consideration, access to genomic testing and a rigorous approach to utility are critical to individual patients and the field of hematology. In this review, we use 3 cases of genomic testing in pediatric hematology to illustrate core ethical concerns and explore potential solutions.