Case Report: First Occurrence of Plasmablastic Lymphoma in Activated Phosphoinositide 3-Kinase δ Syndrome

EBV-positive diffuse large B cell lymphoma secondary to activated phosphoinositide 3 kinase δ syndrome type 1 (APDS1): a case report and literature review

Activated phosphoinositide 3-kinase δ syndrome (APDS), an inborn error of immunity associated with gain-of-function mutations in the PIK3CD gene, is characterized by dysregulated PI3Kδ signaling. The clinical spectrum commonly includes recurrent respiratory infections and lymphoproliferative manifestations. We present an adolescent male with APDS1 manifesting recurrent sinopulmonary infections, generalized lymphadenopathy, hepatosplenomegaly, gastrointestinal manifestations, and combined T-cell/B-cell lymphopenia, complicated by Epstein-Barr virus-positive diffuse large B-cell lymphoma (EBV+ DLBCL). Whole-exome sequencing identified a heterozygous PIK3CD variant (c.3061G>A p.Glu1021Lys), supporting the molecular diagnosis of APDS1. This case adds to emerging evidence linking APDS1 with EBV-driven lymphomagenesis, thereby further supporting the critical role of PI3K δ pathway dysregulation in promoting EBV-associated lymphoid malignancies.

Overall survival among patients with activated phosphoinositide 3-kinase delta syndrome (APDS)

BACKGROUND

This study aimed to describe overall survival (OS) of patients with APDS relative to the global population as well as among subsets of patients with concurrent lymphoma or hematopoietic stem cell transplant (HSCT) relative to the overall APDS population.

METHODS

Patient-level data were extracted from a recent systematic literature review of 351 unique patients with APDS. OS was evaluated using the Kaplan-Meier method up to age 65 years. OS rate and corresponding 95% CI were reported at each decade of age. Global mortality estimates were obtained from World Health Organization life tables for 2019.

RESULTS

Of the 351 patients with APDS (APDS1, 267 [76.1%]; APDS2, 83 [23.6%]; unspecified, 1 [0.3%]), 41 (11.7%) died. The OS rate was 25.0% (95% CI, 1.6-62.7%) by the last death event at 64 years of age. Starting at 12 years of age, the OS rate was numerically lower in patients with APDS relative to the global population (median OS, 64 vs. 75 years, respectively). Relative to the overall APDS population, OS rates were numerically similar in those who underwent HSCT (median OS, 64 years for both; p = 0.569), whereas OS rates were numerically lower in patients with concurrent lymphoma (median OS, 41 vs. 64 years, respectively; p = 0.109). Publication bias in source data was a possible limitation.

CONCLUSION

Reduced survival in patients with APDS suggests a high disease burden, particularly in those with concurrent lymphoma. These results highlight the unmet need for disease-modifying treatments for APDS.

Genetic Etiologies and Outcomes in Malignancy and Mortality in Activated Phosphoinositide 3-Kinase Delta Syndrome: A Systematic Review

INTRODUCTION

This analysis evaluated literature on patients with activated phosphoinositide 3-kinase delta syndrome (APDS) to better understand the genetic etiologies and occurrence of mortality in this population.

METHODS

A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses approach, including all articles published in English prior to March 13, 2023, in PubMed and Embase. Patients included in the study had reported either (1) APDS diagnosis or (2) ≥ 1 clinical sign consistent with APDS and a first-degree relative with genetically confirmed APDS. Reported age at last observation was also a required outcome. Publications not meeting these criteria were excluded. Data were summarized using descriptive statistics.

RESULTS

The search identified 108 publications describing 351 unique patients with 39 distinct disease-causing variants. Among these, 41 (12%) deaths were reported, with a mean age at last follow-up of 19.6 (range, 1-64) years. A cause of death was reported for 80% (33/41) of deaths; lymphoma (24%, 10/41) and infections (22%, 9/41) were the most common causes. Types of infections causing death were severe uncontrollable infections (n = 3), sepsis (n = 2), viral infection (varicella zoster pneumonitis [n = 1], cytomegalovirus and adenovirus [n = 1], and Epstein-Barr virus [n = 1]), and infection (n = 1). Mean age at death for lymphoma was 24.9 (range, 1-41) years, and all nine patients who died from infections died before the age of 15 years. The mean age at first APDS symptom was 2.0 (range, < 1-22) years, and mean age at APDS diagnosis was 13.4 (range, 0-56) years; the mean time between symptoms and diagnosis was 10.6 (range, 0-44) years. Limitations of the study were primarily related to the data source.

CONCLUSION

Patients with APDS suffer early mortality, largely from lymphoma and infection, with large time gaps between symptoms and diagnosis. These findings highlight the need for improved diagnostics, earlier genetic testing for APDS, increased awareness of familial testing, and targeted therapies.

Case Report: Early-onset or recalcitrant cytopenias as presenting manifestations of activated PI3Kδ syndrome

Background

Patients with recurrent, chronic, or refractory cytopenias represent a challenging subgroup that may harbor an underlying diagnosis, such as an inborn error of immunity (IEI). Patients with IEIs such as activated phosphoinositide 3-kinase delta syndrome (APDS), frequently have hematologic manifestations, but these are not often reported as presenting symptoms. As a result, IEIs may be overlooked in patients presenting with early and/or recalcitrant cytopenias. Here, we describe the diagnostic journey and management of three patients who presented to a pediatric hematologist/oncologist with early-onset or recalcitrant cytopenias and were ultimately diagnosed with APDS.

Case presentations

Patients presented with early-onset and/or refractory cytopenias, with two of the three developing multilineage cytopenias. Prior to an APDS diagnosis, two patients underwent a total of approximately 20 procedures, including biopsies, invasive endoscopies, and imaging, with one undergoing eight differential diagnoses that were ruled out through additional testing. Recalcitrant cytopenias, a history of infection, and a family history of lymphoproliferation, infection, or autoimmunity raised suspicion of an underlying IEI, leading to genetic testing. Genetic testing identified a pathogenic variant of PIK3CD in each patient, resulting in the diagnosis of APDS. Following these diagnoses, two patients underwent modifications in the management of care with the administration of intravenous immunoglobulin therapy (IVIG), the mTOR inhibitor sirolimus, or surgical procedures. These treatment modifications either improved or resolved the cytopenias. The third patient showed improvement in immune thrombocytopenia with IVIG 1 month prior to receiving a definitive diagnosis. Following diagnosis, follow-up genetic testing of family members led to the identification of additional cases of APDS.

Conclusions

These cases highlight the importance of early genetic evaluation in patients with early-onset or recalcitrant cytopenias and demonstrate the challenges of differential diagnosis. In addition, these cases demonstrate beneficial changes in management and outcomes that can follow a definitive diagnosis, including the identification of targeted treatment options. Collectively, this case series supports the notion that underlying IEIs should be considered in the workup of early-onset or recalcitrant cytopenias, particularly in patients who present with a combination of hematologic and immunologic manifestations that are refractory to treatment, manifest at an unusually young age, or can be tied to family history.

Pediatric Plasmablastic Lymphoma in the Setting of CD70 Deficiency

Combined immunodeficiency due to CD70 deficiency is characterized by increased susceptibility to infections, hypogammaglobulinemia, and malignancy. These patients typically present with chronic Epstein Barr virus (EBV) viremia, severe EBV-related hemophagocytic lymphohistiocytosis, lymphoproliferation, and Hodgkin and non-Hodgkin lymphomas. Plasmablastic lymphoma (PBL) is an extremely rare malignancy in all ages and is predominantly seen in male adults with human immunodeficiency virus infection. EBV infection, immunosuppression, solid organ transplantation, and age-related immune deterioration are also suspected causes of PBL. Nevertheless, there is scarce data about its association with primary immunodeficiencies in the literature. Here, we present the first case of a CD70 -deficient pediatric patient with PBL.

Cancer Trends in Inborn Errors of Immunity: A Systematic Review and Meta-Analysis

BACKGROUND

Patients with inborn errors of immunity (IEI) are susceptible to developing cancer due to defects in the immune system. The prevalence of cancer is higher in IEI patients compared to the immunocompetent population and cancers are considered as an important and common cause of death in IEI patients.

OBJECTIVES

To systematically review demographic, genetic and cancer-related data of IEI patients with a history of malignancy. Moreover, we performed a meta-analysis aiming to determine the frequency of cancer in patients with different types of IEI.

METHODS

We conducted electronic searches on Embase, Web of Science, PubMed, and Scopus (until September 2023) introducing terms related to IEI and cancer. Studies with human subjects with confirmed IEI who had developed at least one malignancy during their lifetime were included.

RESULTS

A total number of 4607 IEI patients with a cancer history were included in the present study. Common variable immunodeficiency (CVID) had the highest number of reported cases (1284 cases), mainly due to a higher relative proportion of patients with predominantly antibody deficiencies (PAD) and their increased life expectancy contributing to the higher detection and reporting of cancers among these patients. The most common malignancy was hematologic/blood cancers (3026 cases, mainly diffuse large B cell lymphoma). A total number of 1173 cases (55.6%) succumbed to cancer, with the highest rate of bone marrow failure (64.9%). Among the patients with monogenic defects in IEI-associated genes, the majority of cases had ATM deficiency (926 cases), but the highest cancer frequency rate belonged to NBS1 deficiency (50.5%). 1928 cases out of total 4607 eligible cases had detailed data to allow further statistical analysis that revealed BRCA2 deficiency had the earliest cancer development (~ 38 months), lowest cure frequency, and highest fatality rate (85%), while ATM deficiency had the lowest cure frequency and highest fatality rate (72%) among total cases reviewed with exclusion of Fanconi anemia.

CONCLUSION

The overall reported cancer frequency in the cases reviewed with and without exclusion of Fanconi anemia was 11.1% (95% confidence interval: 9.8-12.5%) and 12.0% (95% confidence interval: 10.6-13.5%), respectively. Our study revealed that the incidence of cancer is significantly dependent on the molecular and pathway defects in IEI patients, and individualized early screening and appropriate treatment, might improve the prognosis of these patients.

Systematic review of mortality and survival rates for APDS

Activated phosphoinositide 3-kinase delta syndrome (APDS) is a rare genetic disorder that presents clinically as a primary immunodeficiency. Clinical presentation of APDS includes severe, recurrent infections, lymphoproliferation, lymphoma, and other cancers, autoimmunity and enteropathy. Autosomal dominant variants in two independent genes have been demonstrated to cause APDS. Pathogenic variants in PIK3CD and PIK3R1, both of which encode components of the PI3-kinase, have been identified in subjects with APDS. APDS1 is caused by gain of function variants in the PIK3CD gene, while loss of function variants in PIK3R1 have been reported to cause APDS2. We conducted a review of the medical literature and identified 256 individuals who had a molecular diagnosis for APDS as well as age at last report; 193 individuals with APDS1 and 63 with APDS2. Despite available treatments, survival for individuals with APDS appears to be shortened from the average lifespan. A Kaplan-Meier survival analysis for APDS showed the conditional survival rate at the age of 20 years was 87%, age of 30 years was 74%, and ages of 40 and 50 years were 68%. Review of causes of death showed that the most common cause of death was lymphoma, followed by complications from HSCT. The overall mortality rate for HSCT in APDS1 and APDS2 cases was 15.6%, while the mortality rate for lymphoma was 47.6%. This survival and mortality data illustrate that new treatments are needed to mitigate the risk of death from lymphoma and other cancers as well as infection. These analyses based on real-world evidence gathered from the medical literature comprise the largest study of survival and mortality for APDS to date.

Hematopoietic stem cell transplantation in a patient with activated phosphoinositide 3-kinase δ syndrome: A case report and literature review

Activated phosphoinositide 3-kinase δ syndrome (APDS) is a recently described disease characterized by recurrent infections, lymphoproliferation with a high risk of malignancy, early-onset cytopenia, and a propensity for autoimmune diseases. Hematopoietic stem cell transplantation (HSCT) has proven to be an effective treatment method; however, the recovery process after HSCT is prolonged and accompanied by complications. In this study, we present the case of a patient with APDS type 1. Despite showing signs of immunodeficiency at the age of 6 months, it took almost 6 years to reach a definitive diagnosis. The patient experienced recurrent infections, often accompanied by anemia requiring transfusions, and multifocal nonmalignant lymphoproliferation. Only after receiving the appropriate diagnosis was it possible to implement proper and accurate treatment. HSCT was performed when the patient was 6 years old, leading to significant improvement in his condition. At the 17-month post-HSCT follow-up, the boy is asymptomatic and in good general health, although close monitoring continues due to mixed chimerism and delayed humoral immune recovery. Applying HSCT before the patient develops malignancy contributes to expanding the use of HSCT as a treatment option for APDS type 1.