Autoantibodies Detected in MIS-C Patients due to Administration of Intravenous Immunoglobulin

The autoantibody profile associated with known autoimmune diseases in patients with COVID-19 or multisystem inflammatory syndrome in children (MIS-C) remains poorly defined. Here we show that adults with COVID-19 had a moderate prevalence of autoantibodies against the lung antigen KCNRG, and SLE-associated Smith autoantigen. Children with COVID-19 rarely had autoantibodies; one of 59 children had GAD65 autoantibodies associated with acute insulin-dependent diabetes. While autoantibodies associated with SLE/Sjogren syndrome (Ro52, Ro60, and La) and/or autoimmune gastritis (gastric ATPase) were detected in 74% (40/54) of MIS-C patients, further analysis of these patients and of children with Kawasaki disease (KD), showed that the administration of intravenous immunoglobulin (IVIG) was largely responsible for detection of these autoantibodies in both groups of patients. Monitoring in vivo decay of the autoantibodies in MIS-C children showed that the IVIG-derived Ro52, Ro60, and La autoantibodies declined to undetectable levels by 45-60 days, but gastric ATPase autoantibodies declined more slowly requiring >100 days until undetectable. Together these findings demonstrate that administration of high-dose IVIG is responsible for the detection of several autoantibodies in MIS-C and KD. Further studies are needed to investigate autoantibody production in MIS-C patients, independently from IVIG administration.

474. Unique Treatment Challenges with Multisystem Inflammatory Syndrome in Children (MIS-C) compared to Kawasaki Disease Shock Syndrome

Background Kawasaki disease (KD) and Multisystem Inflammatory Syndrome in Children (MIS-C) associated with Coronavirus Disease 2019 present similarly with mucocutaneous symptoms and fever. Both syndromes can progress to shock. Successful treatments for MIS-C are largely based on proven KD management. As more patients with MIS-C are treated, protocols are adjusted. Infectious Diseases (ID) specialists are often early consultants in these cases. Understanding differences in how body systems are affected in MIS-C versus KD is essential for management. Figure 1. Cardiac changes among patients with Kawasaki Disease shock syndrome (KDSS) and Muti-system Inflammatory Syndrome (MIS-C) Methods This is a single hospital comparison of 25 cases of MIS-C with mucocutaneous presentation and symptoms of shock and 25 consecutive cases of KD Shock Syndrome (KDSS). Cases were compared for demographics, symptoms, cardiac abnormalities, medical treatments, and cardiac recovery. Results Patients with MIS-C develop symptoms of shock including sustained hypotension and tachycardia at 3 times the rate of patients with KD (45% vs 13%; p< 0.001). On echocardiogram, left ventricular myocardial dysfunction, assessed by ejection fraction, is more commonly noted in cases of MIS-C than KDSS (fig 1). About half of patients with MIS-C show left ventricular myocardial dysfunction initially with normalization by 6 months post-presentation in the majority (96%). Conclusion Cardiac changes and shock events related to KD and MIS-C are thought to be caused by differing inflammatory mediators. By comparing these two syndromes, we can determine ways to manage each optimally. MIS-C often results in left ventricular myocardial dysfunction, which is rarer in KD cases. Fluid resuscitation with multiple fluid boluses followed by inotropes to treat hypotension in cases of in MIS-C puts increased strain on the already weakened myocardium. Early intravenous immunoglobulin (IVIG) administration, even in the presence of mild hypotension, can simultaneously provide the patient with additional fluid and decrease the underlying inflammatory process. This prompt treatment might reduce the need for pressor support while protecting the myocardium from further damage. As early consultants in MIS-C, ID providers should be educated regarding the unique cardiac challenges of MIS-C and avoid delay in IVIG treatment and cardiologist and intensivist consultation. Disclosures All Authors: No reported disclosures

Clinical characteristics of Kawasaki disease in adolescents

Objective Studies focusing on Kawasaki disease (KD) in adolescents are lacking in Southwest China. We systematically summarized the clinical characteristics of KD in adolescents to improve pediatricians’ recognition of this condition. Methods The clinical data of patients with adolescent-onset KD in our center were retrospectively analyzed. The patients were divided into Group A (n = 7), whose first hospitalization was at our hospital, and Group B (n = 10), who were transferred from their local hospital or community health center. Results Seventeen patients with adolescent-onset KD were identified (constituent ratio of 0.8%). Seven patients had an intermittent fever for >10 days. The incidence of incomplete KD was 52.9%. These patients had a high incidence of other atypical clinical manifestations. Fifteen patients were initially misdiagnosed with other infectious diseases. Although the incidence of typical KD was higher in Group B, the overall misdiagnosis rate at the initial stages was higher and the average fever duration on arrival and before IVIG administration were much longer in Group B than A. Conclusions KD in adolescents was frequently misdiagnosed, which might be associated with its atypical, diverse clinical features and pediatricians’ poor recognition. Pediatricians must be aware of the possibility of KD in adolescents.

The effect of intravenous immunoglobulin on the course of acute respiratory disease COVID-19. Own observations

The 2019 coronavirus disease (COVID-19) has infected people in many countries around the world. The discovery of an effective treatment for this disease, especially in severe cases, has been the subject of intensive scientific research. Therefore, the aim of this study was to evaluate the effectiveness of intravenous immunoglobulin (IVIG) administration in patients with severe COVID-19 infection. Patients with acute respiratory disease COVID-19 who received intravenous immunoglobulin in the intensive care unit were exami­ned. All patients underwent non-invasive ventilation and all patients had concomitant pathology. Twenty patients participated in the study, 10 patients received an infusion of intravenous immunoglobulin. Patients who received IVIG were on invasive pulmonary ventilation for an average of 7 days, the condition of patients improved by days 2–3. At the time of transfer to adjacent departments (on ave­rage, day 14), the dynamics of the disease improved. Respiration rate was 23 per 1 min. SpO2 without O2 was 92 %. All patients presented with lymphopenia and increased transaminases level, the values of which normalized by days 2–3. When ultrasound examination of the lungs, there were no pulmonary consolidations in patients. Mortality in the group of patients who received IVIG was lower compared to patients who did not receive IVIG.

Efficacy and safety associated with the infusion speed of intravenous immunoglobulin for the treatment of Kawasaki disease: a randomized controlled trial

Background High-dose intravenous immunoglobulin (IVIG) is the mainstay of treatment for Kawasaki disease (KD). Usually, 2 g/kg of IVIG is administered over 10–24 h, depending on the institution or physician, but the association between infusion speed and effectiveness has not been reported. In this study, we evaluated the differences in efficacy and safety between two different IVIG administration speeds. Methods This was a multicenter, unblinded, randomized controlled study. Patients newly diagnosed with KD were randomized into two groups: one who received IVIG over 12 h (12H group, double speed), and one that received IVIG over 24 h (24H group, reference speed). The endpoints included the duration of fever, incidence of coronary artery abnormalities (CAAs) and of adverse events. Laboratory data were evaluated before and after IVIG administration. Results A total of 39 patients were enrolled. There was no difference between groups in fever duration after the initiation of IVIG (21 h vs. 21.5 h, p = 0.325), and no patient experienced CAAs. Two adverse events were observed in the 12H group (elevation of aspartate aminotransferase and vomiting), however no severe adverse events requiring treatments or extension of hospital stay were observed in either group. After initial IVIG administration, the change ratio of inflammatory markers, such as white blood cell counts, neutrophils, C-reactive protein, and albumin, did not show significant differences between the two groups. On the other hand, a greater increase of serum immunoglobulin G from its baseline level was observed in the 24H group compared to the 12H group (3037 ± 648 mg/dl vs. 2414 ± 248 mg/dl, p < 0.01). Conclusion The efficacy and safety of IVIG administered over 12 h (double speed) were similar to those administered over 24 h (reference speed). Trial registration University Hospital Medical Information Network (UMIN000014665). Registered 27 July 2014 – Prospectively registered, https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000017058

Successful prenatal therapy of anti-CD36-mediated severe FNAIT by deglycosylated antibodies in a novel murine model

Recent studies have demonstrated that maternal anti-CD36 antibodies represent a frequent cause of fetal/neonatal alloimmune thrombocytopenia (FNAIT) in Asian and African populations. However, little is known about the pathomechanism and antenatal treatment of anti-CD36-mediated FNAIT. Here, we established a novel animal model to examine the clinical features of pups from immunized Cd36-/- female mice after breeding with wild-type male mice. Mild thrombocytopenia was observed, but high pup mortality was also documented (40.26%). IVIG (1 g/kg) administration on days 7, 12, and 17 to immunized Cd36-/- mothers after breeding reduced fetal death (12.70%). However, delaying the IVIG administration series on days 10, 15, and 20 did not reduce fetal death (40.00%). In contrast, injection of deglycosylated anti-CD36 (deg-anti-CD36) polyclonal antibodies (5 mg/kg) on days 10, 15, and 20 significantly reduced fetal death (5.26%). Subsequently, monoclonal antibodies (mAbs) against mouse CD36 were developed, and one clone producing high-affinity anti-CD36 (termed 32-106) effectively inhibited maternal antibody binding and was therefore selected. Using the same approach of deg-anti-CD36, the administration of deg-32-106 significantly reduced fetal death (2.17%). Furthermore, immunized Cd36-/- mothers showed placenta deficiency. Accordingly, maternal anti-CD36 antibodies inhibited angiogenesis of placenta endothelial cells, which could be restored by deg-32-106. In summary, maternal anti-CD36 antibodies caused a high frequency of fetal death in our animal model, associated with placental dysfunction. This deleterious effect could be diminished by the antenatal administration of IVIG and deg-mAb 32-106. Interestingly, treatment with deg-32-106 appears more beneficial considering the lower dose, later start of treatment, and therapy success.

Low-Dose Prednisone Treatment for IVIG-Resistant Kawasaki Disease with Severe Arthritis and Joint Effusion in Two 3-Year-Old Children

Kawasaki disease (KD) is a global disease in children. The etiology and pathogenesis are unknown. Complications vary among patients. Fever can persist in some after immune globulin (IVIG) administration, termed IVIG-resistant KD. Here, we report two cases of IVIG-resistant KD with severe arthritis. The diagnosis of arthritis was confirmed by magnetic resonance imaging (MRI) showing joint effusion. Remarkably, fever and joint pain had not receded after the second dose of IVIG. To further manage the symptoms, we prescribed low-dose oral prednisone with success. Both fever and joint pain were diminished. We ponder that the low-dose prednisone might be an option to treat IVIG-resistant KD with severe arthritis.

Combined Central Retinal Vein and Cilioretinal Artery Occlusion in the Setting of Intravenous Immunoglobulin Administration

Purpose: This work reports a case of combined vascular occlusion in the setting of intravenous immunoglobulin (IVIg) administration. Methods: The authors describe a case of combined central retinal vein and cilioretinal artery that occurred in the setting of IVIg administration. Results: A 52-year-old White man presented with a unilateral subjective scotoma that began during IVIg administered for the treatment of statin-induced necrotizing autoimmune myopathy. Examination and optical coherence tomography imaging revealed a combined nonischemic central retinal vein and cilioretinal artery occlusion. Conclusions: To the authors’ review and knowledge, this is the first reported case of combined central retinal vein and cilioretinal artery occlusion occurring in the setting of IVIg administration. This rare adverse effect is an entity to be considered in patients who are treated with IVIg.

Intravenous immunoglobulin for corticosteroid-resistant intestinal Henoch-Schönlein purpura: worth a controlled trial against corticosteroids?

Objectives Henoch–Schönlein purpura (HScP) may present in children with severe, occasionally refractory, gastrointestinal (GI) involvement. The use of corticosteroids (CSs) is commonplace in the management of the disease, but to date no standardized protocol is available and, although rare, resistance to CS therapy may be challenging to clinicians. IVIG has been proposed as an effective alternative to CSs, but to date no controlled trial has been conducted to ascertain their real efficacy. We share our personal experience of successful IVIG treatment in two cases of GI HScP, comparing it with similar experiences reported in literature. Methods Retrospective clinical data collection, comparison with available literature. Results We describe two children with severe HScP GI vasculitis refractory to high-dose intravenous CSs that responded rapidly to IVIG administration, with complete recovery within a few days. Patient characteristics and response to IVIG administration were comparable to those of other previously reported cases. Conclusion Our observation confirms that IVIG may be useful in the treatment of CS-resistant HScP-related GI vasculitis in children, and highlights the need for more structured research, including a randomized trial against CSs, in order to ascertain their real effectiveness.

346. Eastern Equine Encephalitis and Use of Intravenous Immunoglobulin Therapy and High-Dose Steroids

Background Eastern equine encephalitis (EEE) is a mosquito-borne viral infection with significant neurological morbidity and mortality. The clinical presentation and patient outcomes after treatment with IVIG, high-dose steroids, or standard of care alone in EEE remains unclear. Methods A retrospective observational study of patients admitted to two tertiary academic medical centers in Boston, Massachusetts with EEE from 2005 to 2019. Results Of 17 patients (mean [SD] age, 50 [26] years; 10 (59%) male, and 16 (94%) White race), 17 patients had fever (100%), 15 had encephalopathy (88%), and 12 had headache (71%). Eleven of 14 patients with cerebrospinal fluid (CSF) cell count differential had a neutrophil predominance (mean [SD], 60.6% of white blood cells [22.8]) with an elevated protein level (mean [SD], 112 mg/dL [48.8]). Affected neuroanatomical regions included the basal ganglia (n=9/17), thalamus (n=7/17), and mesial temporal lobe (n=7/17). A total of 11 patients (65%) received IVIG; 8 (47%) received steroids. Of the patients who received IVIG, increased time from hospital admission to IVIG administration correlated with worse long-term disability as assessed by modified Rankin Score (mRS) (r=0.72, p=0.02); steroid use was not associated with mRS score. The mortality was 12%. Figure 1. Imaging Characteristics: Typical Pattern of MRI Involvement and Affected Neuroanatomical Regions in Patients with Eastern Equine Encephalitis. All images displayed are the T2-FLAIR sequence. (A) Representative images of pattern of typical neuroanatomical region involved in one patient with demonstrated involvement of the temporal lobe and pons, temporal lobe and midbrain, and basal gangial by T2-FLAIR hyperintensity (panels left to right). (B) Representative images of patients with mild (mRS 0–2), moderate (mRS 3–4), and severe (mRS 5–6) disability score at discharge. (C) Representative images of one patient over course of hospitalization at days 1, 4, and 10 after admission. (D) Quantification of neuroanatomical region involvement in initial MRI of patients with EEE as determined by T2-FLAIR hyperintensity. An area was scored as abnormal only once per patient. Figure 2. Outcomes in Patients with Eastern Equine Encephalitis. Patient disability by modified Rankin Score (mRS) of EEE patients at admission to the hospital, discharge from the hospital, and last recorded follow-up (A). Time to IVIG administration compared to mRS at discharge (B), and most recent clinical follow-up (C). Table 1. Demographics, Clinical Characteristics, and Laboratory Data in Patients with Eastern Equine Encephalitis. Abbreviations: CSF = cerebrospinal fluid, WBC = white clood count, EEG = electroencephalogram, ALT = alanine aminotransferase, AST = aspartate transaminase. Demographic data was collected for all patients with confirmed EEE. Altered mental status included any description of encephalopathy, confusion, or difficulty with attention. Seizures were defined as clinical events with a high-degree of suspicion to be true seizures, and were entirely comprised of generalized tonic-clonic seizures. Conclusion Clinicians should suspect EEE in immunocompetent patients with early subcortical neuroimaging abnormalities and CSF neutrophilic predominance. This study suggests a lower mortality than previously reported, but a high morbidity rate in EEE. IVIG as an adjunctive to standard of care may be considered early during hospitalization. Disclosures All Authors: No reported disclosures