A retrospective study of paroxysmal nocturnal hemoglobinuria in pediatric and adolescent patients

Childhood aplastic anaemia with paroxysmal nocturnal haemoglobinuria clones: A retrospective single-centre study in South Africa

Background: Paroxysmal nocturnal haemoglobinuria (PNH) clones in children are rare but commonly associated with aplastic anaemia (AA) and myelodysplasia.Objective: This study aimed to determine the prevalence of PNH clones in paediatric patients with idiopathic AA, identify differences in clinical and laboratory features and outcomes, and determine the impact of clone size on clinical presentation.Methods: Patients with confirmed idiopathic AA who were tested for PNH between September 2013 and January 2018 at the Inkosi Albert Luthuli Central Hospital, Durban, KwaZulu-Natal, South Africa, were included. PNH clones were detected in neutrophils and monocytes by flow cytometry using fluorescent aerolysin, CD24, CD66b and CD14.Results: Twenty-nine children with AA were identified and 11 were excluded. Ten patients (10/18, 55.6%) had PNH clones ranging from 0.11% to 24%. Compared to the PNH-negative group, these children were older (median: 10 years vs 4 years, p = 0.02) and had significantly lower total white cell counts (median 1.7 × 109/L vs 3.2 × 109/L; p = 0.04). There was no difference in median absolute neutrophil count or haemoglobin concentration. Four patients in each group received immunosuppressive therapy (IST). At six months, all four patients with PNH clones had responded, compared to one in the PNH-negative group.Conclusion: More than half of children with AA had a PNH clone. The size of the clone did not impact clinical severity; however, IST use may positively impact prognosis. We recommend early initiation of IST in patients with AA to avoid delays associated with human leukocyte antigen typing. 

Evaluating ravulizumab for the treatment of children and adolescents with paroxysmal nocturnal hemoglobinuria

INTRODUCTION

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired clonal stem cell disease harvesting a somatic mutation in the phosphatidylinositol glycan class A (PIG-A) gene. This mutation results in a deficiency in cell membrane complement regulators leading to activation of the terminal complement pathway, clinically presenting as hemolytic anemia and thrombosis, and frequently associated with bone marrow failure. This condition was historically managed with supportive care and bone marrow transplant.

AREAS COVERED

This paper will review primary data on the pharmacology, efficacy, and safety of ravulizumab in the pediatric/adolescent population gathered from literature search from PubMed, abstracts from annual meetings, and medication package inserts. Eligible clinical trials identified on the clinicaltrials.gov website are also briefly discussed.

EXPERT OPINION

: The discovery of eculizumab, a monoclonal antibody against complement protein 5, has revolutionized the PNH landscape, with decreased hemolysis and risk of thrombosis, improved quality-of-life, and has become the standard of care. Ravulizumab, a longer-acting C5-inhibitor with 4 times the half-life of eculizumab, was recently approved for pediatric patients with PNH. Ravulizumab is effective, safe, and has the potential to improve quality of life further. In addition, ongoing clinical trials using second-generation complement inhibitors may provide promising new interventions in PNH.

Pediatric Paroxysmal Nocturnal Hemoglobinuria Presenting as Acute Kidney Injury

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disease characterized by variable and diverse symptoms including the classic triad of hemolytic anemia, thrombosis, and bone marrow failure. It is a disorder primarily seen in the adult population. The authors report a unique case of an 8-year-old girl diagnosed with PNH after initially presenting with a febrile illness and acute kidney injury. Though rare in children, PNH should remain in the differential diagnosis of a child presenting with acute kidney injury. The disease has serious long-term complications, mandating timely diagnosis and appropriate therapy.

Pregnancy with Paroxysmal Nocturnal Hemoglobinuria: A Case Series with Review of the Literature

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired hematopoietic stem cell disorder, and eculizumab and ravulizumab are its two approved therapies. Only few case series/reports have reported the outcomes of pregnancies in patients with PNH despite the increased risk of thrombosis. Similarly, there is limited knowledge regarding the effect of the approved treatments on conception and pregnancy outcomes. Here, we report the first series of pregnancies in PNH patients from the Middle Eastern region from our tertiary care hospital. Ten pregnancies in four females after diagnosis with PNH were identified. In terms of PNH management, only eculizumab was used, as the safety of ravulizumab use in pregnancies has not yet been established. In the antepartum period, the patients had variable symptoms that ranged from mild symptoms including epistaxis, tea-colored urine and vaginal bleeding to life-threatening vessel thrombosis. Further, red blood cell and platelet transfusions were required because of bleeding and hemolysis in four pregnancies. The pregnancy outcomes varied, but based on these, the safety of eculizumab use during pregnancy remained inconclusive. The postpartum period was complicated in one case by portal vein thrombosis and was managed accordingly. In conclusion, pregnant females with PNH are at an increased risk for complications due to PNH, and thus experienced hematologists and obstetricians should be involved jointly in their care.

Paroxysmal Nocturnal Hemoglobinuria: Case Report of a Rare Cause of Thrombosis in the Pediatric Age

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired life-threatening disorder that is extremely rare in the pediatric age. Patients with PNH may present a wide range of clinical manifestations. In most cases, the severity is associated with the size of the PNH clones; yet, some patients can be asymptomatic with a large clone. Thrombosis occurs less frequently as a presenting symptom, but it is considered the leading cause of mortality. In this article, we describe a case of PNH in a pediatric patient, complicated with venous thrombosis and with portal hypertension, associated with gastroesophageal varices at the time of diagnosis.

Complement Inhibition in Severe COVID-19 Acute Respiratory Distress Syndrome

Most children with COVID-19 have asymptomatic or mild illness. Those who become critically ill suffer from acute respiratory distress syndrome (ARDS) and acute kidney injury (AKI). The rapid deterioration of lung function has been linked to microangiopathic and immune-mediated processes seen in the lungs of adult patients with COVID-19. The role of complement-mediated acute lung injury is supported by animal models of SARS-CoV, evaluation of lung tissue in those who died from COVID-19 and response of COVID-19 ARDS to complement inhibition. We present a summary of a child with COVID-19 disease treated with convalescent plasma and eculizumab and provide a detailed evaluation of the inflammatory pathways.

Successful reduced-intensity conditioning hematopoietic stem cell transplantation for paroxysmal nocturnal hemoglobinuria with aplastic anemia in two children

Paroxysmal nocturnal hemoglobinuria (PNH) is an extremely rare cause of bone marrow failure in children. We report two children who presented with pancytopenia, and were diagnosed with PNH with severe aplastic anemia. Both children underwent upfront, successful hematopoietic stem cell transplantation with reduced-intensity conditioning. One patient had a syngeneic donor, and one patient had a 10/10 matched unrelated donor. Neither patient developed graft versus host disease, infections, or recurrent PNH. Reduced-intensity conditioning hematopoietic stem cell transplantation is a reasonable therapy for PNH with marrow failure in children.