Post-streptococcal small-vessel vasculitis in a 16-month-old with associated intussusception and hypertension: Henoch Schönlein purpura?

Henoch Schönlein purpura (HSP), also known as IgA vasculitis, is a systemic small-vessel vasculitis typically occurring in children 3-15 years of age, with peak incidence at 4-6 years. It is characterized by a constellation of symptoms including palpable purpura, arthralgias or arthritis, abdominal pain including intussusception, and renal involvement. We report a patient with these clinical findings whose IgA immunofluorescence was negative but with a presumptive diagnosis of HSP at 16 months of age, significantly younger than the classic population. This condition rarely affects this age group, and we highlight the importance of considering vasculitis in children of all ages, as a failure to diagnose could lead to insufficient long-term monitoring, particularly regarding renal function.

Kawasaki Disease and Inborn Errors of Immunity: Exploring the Link and Implications

The exact etiopathogenesis of Kawasaki disease (KD), the most common childhood vasculitis, remains unknown; however, an aberrant immune response, possibly triggered by an infectious or environmental agent in genetically predisposed children, is believed to be the underlying pathogenetic mechanism. Patients with inborn errors of immunity (IEI) are predisposed to infections that trigger immune dysregulation due to an imbalance in various arms of the immune system. KD may develop as a complication in both primary and secondary immunodeficiencies. KD may occur either at disease presentation or have a later onset in IEIs. These include X-linked agammaglobulinemia (XLA), selective IgA deficiency, transient hypogammaglobulinemia of infancy; Wiskott-Aldrich syndrome (WAS), hyper IgE syndrome (HIES); chronic granulomatous disease (CGD), innate and intrinsic immunity defects, and autoinflammatory diseases, including PFAPA. Hitherto, the association between KD and IEI is confined to specific case reports and case series and, thus, requires extensive research for a comprehensive understanding of the underlying pathophysiological mechanisms. IEIs may serve as excellent disease models that would open new insights into the disease pathogenesis of children affected with KD. The current review highlights this critical association between KD and IEI supported by published literature.

Lung biopsy in the diagnosis of pediatric ANCA-associated vasculitis

OBJECTIVE

To investigate pulmonary histopathologic features in a cohort of pediatric patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) who underwent a lung biopsy as part of their evaluation. We report the safety and the findings of lung biopsies in this population.

METHODS

After IRB approval, we performed a retrospective chart review of all patients <18 years of age presenting to our institution with a diagnosis of pediatric AAV (pAAV) who underwent lung biopsy. We reviewed histopathologic features, serologies, the timing of biopsy, and complications.

RESULTS

Fourteen patients met inclusion criteria, nine patients with microscopic polyangiitis (MPA), and five patients with granulomatosis with polyangiitis (GPA). All patients had positive ANCA serology. 13/14 patients required admission on initial presentation for respiratory symptoms; 11/13 required respiratory support. The indication for biopsy was confirmation of diagnosis before initiating therapy in 11 patients (78%), part of the infectious evaluation in two (14%), and part of interstitial lung disease evaluation in one (7%). 11/14 (78%) biopsies had findings consistent with AAV diagnosis: 6/9 (67%) of the MPA patients compared with 5/5 (100%) of the GPA patients. The most common findings on histopathology were vascular inflammation and signs of alveolar hemorrhage. The only reported complication after lung biopsy was pneumothorax in four patients (28%).

CONCLUSION

Lung biopsy had a higher diagnostic yield in GPA compared with MPA patients. In our cohort, a diagnosis of AAV could be made with clinical features and positive serology but was confirmed by lung histopathology in the majority of cases. Obtaining a lung biopsy for diagnostic purposes in pAAV should be reserved for uncertain cases where the diagnosis cannot be confirmed clinically and with serology.

Clinical Course, Management, and Outcomes of Pediatric Takayasu Arteritis Initially Presenting With Hypertension: A 16-year overview

BACKGROUND

To investigate the clinical features, management, and outcomes of childhood Takayasu arteritis (c-TA) initially presenting with hypertension.

METHODS

This study retrospectively reviewed medical charts of 96 inpatient c-TA cases from January 2002 to December 2016, with 5 additional patients being prospectively recruited from January 2017 to December 2017. Data were compared between c-TA groups initially presenting with and without hypertension. Blood pressure (BP) control, event-free survival, and associated risk factors were assessed by logistic regression, Kaplan-Meier survival curve, and COX regression models.

RESULTS

The hypertensive cohort (N = 71, 28.2% males) as compared with non-hypertensive cohort had significantly fewer active diseases; fewer episodes of claudication, syncope, blurred vision, and myocardial ischemia; and fewer systemic symptoms (P < 0.05). The hypertensive group presented with more localized abdominal lesions (OR = 14.4, P = 0.001) and limited supradiaphragmatic arterial involvement. Renovascular disease (P = 0.001) and revascularization (P = 0.006) were associated with hypertension. At the median 3-year follow-up, 53% of hypertensive patients achieved BP control and 39% experienced events including vascular complications, flares, or death. The 1-, 3-, 5-, and 10-year event-free survival were 78.7% (95% CI: 65.7%-87.2%), 63.0% (95% CI: 48.1%-74.7%), 48.9% (95% CI: 32.0%-63.8%), and 31.6% (95% CI: 13.8%-51.2%), higher than in non-hypertensive group (P = 0.014). Heart failure, stroke, and body mass index <18.5 kg/m2 were prognostic factors for events. Intervention and baseline systolic BP were independent factors for BP control (P < 0.05).

CONCLUSIONS

Majority of c-TA has hypertension, presenting with a more quiescent disease without typical systemic and/or ischemia symptoms, more localized abdominal lesions, higher proportion of revascularizations and better event-free survival. Three-year BP control is more than 50%. Intervention particularly on renal artery is beneficial for BP control and decreased events.

CLINICAL TRIAL REGISTRATION

Trial Number: NCT03199183.

How Should We Classify Kawasaki Disease?

The exact classification of Kawasaki disease (KD) has been debated. Infectious disease specialists have claimed it as an infection with a classic immune responses to an as yet unidentified pathogen that localizes to the coronary arteries. Others have favored an autoreactive hypothesis that KD is triggered by an antigen that shares homology with structures in the vascular wall, and molecular mimicry resulting in an immune response directed to that tissue. Rheumatologists have classified it as a systemic vasculitis, while some immunologists have stressed the robust nature of the innate immune response that causes both systemic inflammation as well as damage to the coronary arterial wall and questioned whether KD falls within the spectrum of autoinflammatory diseases. This review will describe the evidences available up to now regarding these hypotheses.

Eosinophilic granulomatosis with polyangiitis in children: Data from the French RespiRare® cohort

OBJECTIVES

To describe the characteristics of pediatric cases of eosinophilic granulomatosis with polyangiitis (EGPA), a systemic necrotizing vasculitis rarely diagnosed in children, retrieved from the French Reference Center for rare pediatric lung diseases and compared with adult cases included in the French Vasculitis Study Group cohort.

METHODS

We collected information on pediatric EGPA disease presentation, management, and outcome. Cases met the Lanham criteria and/or American College of Rheumatology classification criteria.

RESULTS

Fourteen cases of pediatric EGPA were included, from 1980 to 2012, with a median follow-up of 58.5 months. Median age at diagnosis was 12.3 years. All cases had respiratory involvement. The organ systems most frequently involved were the upper airway (85%), skin (71%), digestive tract (64%), and heart (57%). Neurological and renal involvement were rare. Four of the fourteen children were positive for ANCA (30.7%). During follow-up, three children required intensive care and one child died. The relapse rate was 64%. In comparison with an adult cohort, we found more ENT, heart, and digestive-tract involvement, and fewer neurological manifestations. In children, the delay between asthma onset and diagnosis was shorter, and biopsies showed fewer features of vasculitis.

CONCLUSION

This French cohort is the biggest pediatric EGPA series described to date, with a long follow-up period. The findings confirm that pediatric EGPA has specific clinical, radiological, and histological characteristics that differ from adult EGPA. Development of systemic symptoms, and consequently diagnosis, occur with a shorter delay in children, mainly during the eosinophilic phase and leading to a specific presentation.

The immunomodulatory effects of intravenous immunoglobulin therapy in Kawasaki disease

The introduction of intravenous immunoglobulin (IVIG) for modulation of inflammation in acute Kawasaki disease was a great therapeutic triumph. However, three decades later, the mechanisms underlying immune regulation by IVIG are only beginning to be revealed. Stimulation of an immature myeloid population of dendritic cells that secretes IL-10 and the elucidation of Fc-specific natural regulatory T cells provide insights into the mechanisms of IVIG. Other potential mechanisms include provision of agent-specific neutralizing antibody, anti-idiotype and anti-cytokine antibodies, blockade of activating Fcγ receptors and stimulation of the inhibitory FcγRIIb receptor. New initiatives must seek to understand the mechanisms of IVIG in order to replace it one day with more affordable and more targeted therapies.

Diagnostic approach and current treatment options in childhood vasculitis

All inflammatory changes in the vessel wall are defined as vasculitis. Pediatric vasculitis may present with different clinical findings. Although Henoch-Schönlein purpura which is the most common pediatric vasculitis generally recovers spontaneously, it should be monitorized closely because of the risk of renal failure. Although Kawasaki disease is easy to diagnose with its classical findings, the diagnosis may be delayed in case of incomplete Kawasaki disease. Kawasaki disease should be considered especially in infants in case of prolonged fever even if the criteria are not fully met and intravenous immunoglobulin treatment should be administered without delay in order to prevent development of coronary artery aneurism. Reaction at the site of administration of Bacillus Calmette-Guerin (BCG) vaccine may be observed as commonly as cervical lymphadenopathy in Kawasaki disease and may be used as a valuable finding in suspicious cases. Although anti-neutrophil cytoplasmic antibody-associated vasculitides are rare in children, renal involvement is more common and progression is more severe compared to adults. Hence, efficient and aggressive treatment is required. Takayasu's arteritis is observed commonly in young adult women and rarely in adolescent girls. Therefore, a careful physical examination and blood pressure measurement should be performed in addition to a detailed history in daily practice. In children with unexplained neurological findings, cerebral vasculitis should be considered in the absence of other systemic vasculitides and necessary radiological investigations should be performed in this regard. This review will provide an insight into the understanding of pediatric vasculitis, current diagnostic approaches and prognosis by the aid of new studies.