Pediatric antiphospholipid syndrome: clinical features and therapeutic interventions in a single center retrospective case series

Pediatric antiphospholipid syndrome: expanding our understanding of antiphospholipid syndrome in children

PURPOSE OF REVIEW

Antiphospholipid syndrome (APS) is an autoimmune, thromboinflammatory disease, which affects children and adults. There are particular features of the disease and nuances to diagnosis and management in a pediatric population, which must be appreciated to improve clinical care.

RECENT FINDINGS

Pediatric-specific epidemiological studies highlight that pediatric APS is quite rare with incidence in some populations of 0.2 per 100 000. There are new classification criteria in APS, which include a wider range of clinical features increasingly identified in registry data and case series of pediatric APS, though validation in pediatric APS is still needed. There is a particularly high proportion of pediatric APS patients with noncriteria antiphospholipid antibodies (aPL). Recurrent thrombosis is especially common in pediatric APS, highlighting the difficulty of management of this disease with high morbidity in children.

SUMMARY

Recent research has enhanced understanding of pediatric-specific APS epidemiology, laboratory findings, the wide variety of clinical features, and challenges in successful treatment. Future directions could include evaluation of potentially unique features in pediatric pathophysiology, an evaluation of the new APS classification criteria in children, broader prospective data on clinical and laboratory features, and a continued search for treatment beyond committing young patients to lifelong anticoagulation.

Mechanical thrombectomy in a pediatric patient with antiphospholipid syndrome-a case report

Stroke ranks among the top 10 most common causes of death in children. Recently, there has been a significant increase in the number of strokes in the pediatric population. Mechanical thrombectomy is an uncommon method for treating acute ischemic stroke (AIS) in children. This case report discusses a 13-year-old girl with a history of ischemic stroke for the past 3 months, obesity, hypertension, and antiphospholipid syndrome (APS, treated with rivaroxaban), who suffered another ischemic stroke and underwent mechanical thrombectomy with favorable clinical outcomes. Additionally, the patient was diagnosed with antithrombin III deficiency. It is necessary to identify risk factors for AIS in the pediatric population, such as thrombophilia or autoimmune diseases, such as antiphospholipid syndrome, and to develop guidelines for the use of thrombectomy in children. This method could reduce mortality, improve quality of life, prevent disability, and lower future medical costs.

Antiphospholipid syndrome presenting as isolated renal vein thrombosis: a case report and review of the literature

BACKGROUND

Pediatric antiphospholipid syndrome is a rare systemic autoimmune disorder characterized by recurrent thrombotic events in the presence of antiphospholipid antibodies. Isolated right renal vein thrombosis resulting in a nonfunctional kidney is an uncommon manifestation of antiphospholipid syndrome. Here, we present our experience with antiphospholipid syndrome secondary to systemic lupus erythematosus.

CASE PRESENTATION

A 10 year-old girl from a Hindu family in Sindh, Pakistan, who had previously been healthy, presented in 2020 with a 1-week history of abdominal pain, gross hematuria, vomiting, and fever. On examination, she was anxious, febrile, hypertensive, and had an enlarged, tender right kidney. Other systemic examinations, including skin, locomotor, respiratory, cardiovascular, and nervous systems, were unremarkable. Initial investigations for ureteric colic and acute pyelonephritis were negative, but revealed thrombocytopenia on complete blood count, mild proteinuria, hematuria on urinalysis, and normal kidney and liver function tests, along with normal prothrombin and activated partial thromboplastin times. An abdominal ultrasound showed a diffusely enlarged, echogenic right kidney with a loss of corticomedullary distinction and cortical hypoechoic areas, while the left kidney appeared normal. Color Doppler ultrasound identified a large thrombus in the right renal vein, completely obstructing its lumen and showing no blood flow. The thrombus extended into the inferior vena cava. Computed tomography angiography confirmed an organized thrombus completely blocking the right renal vein and extending into the infrahepatic portion of the inferior vena cava. No prothrombotic risk factors were identified during clinical evaluation, and thrombophilia screening was negative. However, lupus serology and antiphospholipid antibodies were positive, confirming a diagnosis of secondary antiphospholipid syndrome.

MANAGEMENT AND OUTCOME

The patient was treated with enoxaparin anticoagulation, later transitioned to warfarin sodium, and her hypertension was managed with captopril and amlodipine. She showed gradual improvement over 10-12 days and was discharged on anticoagulants, antihypertensive medications, antiplatelet agents, and hydroxychloroquine. A follow-up Doppler ultrasound revealed persistent blockage of the right renal vein by the thrombus, with no thrombus in the inferior vena cava. A dimercaptosuccinic acid scan indicated a nonfunctioning right kidney. While nephrectomy was recommended, her parents declined the procedure. Anticoagulation therapy was switched to rivaroxaban to avoid frequent international normalized ratio monitoring. Her captopril was replaced after control of blood pressure with losartan. Over the next 4 years, her follow-up was uneventful. She demonstrated normal growth, stable blood pressure (off antihypertensive), and normal kidney function without proteinuria. There were no lupus flares or thrombotic recurrences. Her most recent urinalysis was normal, with a serum creatinine level of 0.6 mg/dL and an estimated glomerular filtration rate > 170 mL/min/1.73 m2.

CONCLUSION

Isolated renal vein thrombosis is a rare presentation of antiphospholipid syndrome and poses a diagnostic challenge in the absence of preexisting prothrombotic risk factors. Early diagnosis and timely management are crucial to prevent organ damage. In this case, the patient retained a solitary functioning kidney. Long-term follow-up is essential to monitor for lupus flares, thrombus recurrence, hypertension, proteinuria, and progression to chronic kidney disease, as well as to ensure continued thromboprophylaxis.

Damage Index for Antiphospholipid Syndrome (DIAPS): An Antiphospholipid Syndrome Alliance for Clinical Trials and International Networking (APS ACTION) "Damage" working group report on strengths and limitations

OBJECTIVES

To gather the perspectives of APS ACTION members regarding the strengths and limitations of Damage Index for Antiphospholipid Syndrome (DIAPS); and establish recommendations for the improvement of DIAPS.

METHODS

APS ACTION members were invited to answer a survey regarding their satisfaction with DIAPS scoring system and individual items. The level of agreement (LoA) among members with the inclusion of individual items in DIAPS was calculated (LoA of <75% was considered disagreement). Respondents' open-ended comments about DIAPS limitations were also collected, which helped formulate our recommendations for DIAPS improvement.

RESULTS

Forty-two APS ACTION members (58.3%) answered the survey. Of them, 26 (61.9%) were satisfied, 4 (9.5%) were neutral, and 12 (28.6%) were dissatisfied with the current DIAPS scoring system. Fifteen items (39.5%) presented a LoA <75% regarding the inclusion in DIAPS. Respondents provided comments that were grouped under six main categories related to concerns about: a) definitions and attribution of damage (including causality and temporal relationship); b) scoring system; c) overlapping items; d) specific items (exclusion of redundant items and inclusion of additional ones); e) the need to incorporate multiple events; and f) feasibility and practicality. Finally, the APS ACTION "Damage" Working Group developed 7 recommendations that should be considered for the next generation DIAPS.

CONCLUSION

Approximately 60% of respondents were satisfied with DIAPS and its definitions; however, our survey demonstrated that there is substantial room to improve the current damage index for APS. Efforts for updating DIAPS should consider the APS ACTION "Damage" Working Group recommendations.

Pediatric antiphospholipid syndrome: is it the same as an adult?

IMPORTANCE

Antiphospholipid syndrome in neonates and children is a rare, but in some cases life-threatening condition with arterial and/or venous thrombosis and/or non-thrombotic neurological, skin, ophthalmological and other manifestations.

OBSERVATIONS

This review highlights the available information about the features of pediatric APS, including the rare catastrophic form, the differences between pediatric and adult APS, and the role of genetic thrombophilia in APS manifestation.

CONCLUSIONS AND RELEVANCE

The clinical manifestations and treatment options for APS in children may differ from those in adults, and prescribing therapy can be challenging due to the unique clinical and morphological characteristics of the pediatric patient. Pediatric APS may be a predictor of the development of certain autoimmune diseases and classic manifestations of APS in adulthood, therefore, a revision of the existing criteria for the diagnosis and treatment of APS in children is necessary.

Updates in diagnosis and treatment of pediatric antiphospholipid syndrome

PURPOSE OF REVIEW

This review offers an overview of the most important recent articles on pediatric APS.

RECENT FINDINGS

Non-thrombotic extra criteria manifestations were prevalent in pediatric APS. Pregnancy morbidity has been described as the first manifestation of APS at youth age, impairing gestational outcomes. The 2023 APS criteria were developed for adult APS patients, and there is still a lack of pediatric-specific APS criteria. Catastrophic APS was more commonly reported as the initial manifestation of pediatric APS than in adults. Regarding treatment, direct oral anticoagulants have been recently approval for pediatric patients with venous thrombosis. New approaches have been proposed for severe cases, for arterial thrombosis, and rituximab for refractory cases. Recurrences typically occurred early and were associated with older age at diagnosis. Current studies highlighted the multifaceted nature of pediatric APS. Further large prospective multicenter studies evaluating new medications capable of reducing recurrence risk and improving prognosis in this population will be required.

Immunothrombosis: A bibliometric analysis from 2003 to 2023

BACKGROUND

Immunothrombosis is a physiological process that constitutes an intravascular innate immune response. Abnormal immunothrombosis can lead to thrombotic disorders. With the outbreak of COVID-19, there is increasing attention to the mechanisms of immunothrombosis and its critical role in thrombotic events, and a growing number of relevant research papers are emerging. This article employs bibliometrics to discuss the current status, hotspots, and trends in research of this field.

METHODS

Research papers relevant to immunothrombosis published from January 1, 2003, to May 29, 2023, were collected from the Web of Science Core Collection database. VOSviewer and the R package "Bibliometrix" were employed to analyze publication metrics, including the number of publications, authors, countries, institutions, journals, and keywords. The analysis generated visual results, and trends in research topics and hotspots were examined.

RESULTS

A total of 495 target papers were identified, originating from 58 countries and involving 3287 authors from 1011 research institutions. Eighty high-frequency keywords were classified into 5 clusters. The current key research topics in the field of immunothrombosis include platelets, inflammation, neutrophil extracellular traps, Von Willebrand factor, and the complement system. Research hotspots focus on the mechanisms and manifestations of immunothrombosis in COVID-19, as well as the discovery of novel treatment strategies targeting immunothrombosis in cardiovascular and cerebrovascular diseases.

CONCLUSION

Bibliometric analysis summarizes the main achievements and development trends in research on immunothrombosis, offering readers a comprehensive understanding of the field and guiding future research directions.

Non-criteria antiphospholipid antibodies and calprotectin as potential biomarkers in pediatric antiphospholipid syndrome

Our study aimed to evaluate the presence, clinical associations, and potential mechanistic roles of non-criteria antiphospholipid antibodies (aPL) and circulating calprotectin, a highly stable marker of neutrophil extracellular trap release (NETosis), in pediatric APS patients. We found that 79% of pediatric APS patients had at least one non-criteria aPL at moderate-to-high titer. Univariate logistic regression demonstrated that positive anti-beta-2 glycoprotein I domain 1 (anti-D1) IgG (p = 0.008), anti-phosphatidylserine/prothrombin (aPS/PT) IgG (p < 0.001), and aPS/PT IgM (p < 0.001) were significantly associated with venous thrombosis. Positive anti-D1 IgG (p < 0.001), aPS/PT IgG (p < 0.001), and aPS/PT IgM (p = 0.001) were also associated with non-thrombotic manifestations of APS, such as thrombocytopenia. Increased levels of calprotectin were detected in children with APS. Calprotectin correlated positively with absolute neutrophil count (r = 0.63, p = 0.008) and negatively with platelet count (r = -0.59, p = 0.015). Mechanistically, plasma from pediatric APS patients with high calprotectin levels impaired platelet viability in a dose-dependent manner.

Ischemic Stroke as an Initial Manifestation of Antiphospholipid Syndrome in an Adolescent: A Case Report

Cerebrovascular diseases in pediatric patients are relatively rare. Ischemic stroke in adolescents is associated with a poor prognosis. The most common causes include systemic diseases, such as heart disease and hypercoagulation disorders. It is important to mention that one of the most common acquired hypercoagulation states is the antiphospholipid syndrome (APS). Patients with this disease may present stroke as the first clinical manifestation, which not only increases morbidity in these patients but presents a diagnostic challenge. This case presents one example of how APS can present as a pediatric stroke. The diagnostic approach should always be through the presence of specific antibodies accompanied by the presence of a thromboembolic episode proven by catheterization or an imaging study. In the brain, the preferred imaging study is magnetic resonance imaging. Management is based on anticoagulation therapy and continuous monitoring in the intensive care unit.

Pediatric Presentation of Antiphospholipid Syndrome: A Review of Recent Literature With Estimation of Local Prevalence

We aimed to investigate the epidemiology, the clinical and laboratory characteristics of the pediatric involvement of antiphospholipid syndrome (APS), by performing a review of the current evidence and reviewing local experience in the Northwest Italy. To achieve this, we performed a detailed literature search to identify articles describing clinical and laboratory characteristics of pediatric APS. In concomitance, we conducted a registry-based study collecting data from the Piedmont and Aosta Valley Rare Disease Registry including pediatric patients diagnosed with APS in the last 11 years. The literature review led to inclusion of six articles with a total of 386 pediatric patients (65% females, 50% with systemic lupus erythematosus (SLE) as concomitant diagnosis). Rates of venous and arterial thrombosis were 57 and 35%, respectively. "Extra-criteria manifestations" included mostly hematologic and neurologic involvement. Almost one-quarter of patients (19%) reported recurrent events and 13% manifested as catastrophic APS. A total of 17 pediatric patients (mean age 15.1 ± 2.8, 76% female) developed APS in the Northwest of Italy. In 29% of cases, SLE was a concomitant diagnosis. Deep vein thrombosis was the most frequent manifestation (28%) followed by catastrophic APS (6%). The estimated prevalence of pediatric APS in Piedmont and Aosta Valley Region is 2.5/100,000 people, whereas the estimated annual incidence is 0.2/100,000 inhabitants. In conclusion, clinical manifestations of pediatric APS seem to be more severe and with a high prevalence of noncriteria manifestations. International efforts are needed to better characterize this condition and to develop new specific diagnostic criteria to avoid missed/delayed diagnosis in children with APS.

Antiphospholipid syndrome: advances in diagnosis, pathogenesis, and management

Antiphospholipid syndrome (APS) is a thrombo-inflammatory disease propelled by circulating autoantibodies that recognize cell surface phospholipids and phospholipid binding proteins. The result is an increased risk of thrombotic events, pregnancy morbidity, and various other autoimmune and inflammatory complications. Although antiphospholipid syndrome was first recognized in patients with lupus, the stand alone presentation of antiphospholipid syndrome is at least equally common. Overall, the diagnosis appears to affect at least one in 2000 people. Studies of antiphospholipid syndrome pathogenesis have long focused on logical candidates such as coagulation factors, endothelial cells, and platelets. Recent work has shed light on additional potential therapeutic targets within the innate immune system, including the complement system and neutrophil extracellular traps. Vitamin K antagonists remain the mainstay of treatment for most patients with thrombotic antiphospholipid syndrome and, based on current data, appear superior to the more targeted direct oral anticoagulants. The potential role of immunomodulatory treatments in antiphospholipid syndrome management is receiving increased attention. As for many systemic autoimmune diseases, the most important future direction is to more precisely identify mechanistic drivers of disease heterogeneity in pursuit of unlocking personalized and proactive treatments for patients.

Case Report: A case of recurrent thrombosis in pediatric antiphospholipid syndrome associated with pediatric onset systemic lupus

Systemic lupus erythematosus (SLE) is an autoimmune disease with multi-system involvement as the main manifestation, and has complex and diverse clinical features. Studies on large samples have revealed that SLE patients have a significantly increased risk of thrombotic events, which are also one of the important causes of morbidity and mortality in SLE patients. Antiphospholipid syndrome (APS) is a rare autoimmune disorder characterized by recurrent arterial and venous thrombosis, pregnancy-related complications, and the persistence of antiphospholipid antibodies at a 12-week interval. There are few reports about SLE coexisting with APS in children. This paper reported a school-age patient who started the disease with gross hematuria after bumping into the waist. The initial diagnosis of renal contusion was then confirmed by color Doppler ultrasound as renal vein and inferior vena cava embolism. She suddenly developed severe chest pain and dyspnea 3 days after hospitalization. And imaging supported pulmonary embolism with massive proteinuria, hypoalbuminemia, and hypercholesterolemia. The initial diagnosis was nephrotic syndrome (NS) with arteriovenous embolization, and popliteal vein embolism occurred again 5 years later, and she was thus diagnosed with SLE coexisting with APS. Afterwards, we discussed the possible mechanism and therapeutic strategies of SLE&APS that started with nephrotic syndrome, in order to achieve early identification and treatment of the disease and improve the prognosis of children.