Risk Factors Associated with Intensive Care Admission in Children with Severe Acute Respiratory Syndrome Coronavirus 2-Related Multisystem Inflammatory Syndrome (MIS-C) in Latin America: A Multicenter Observational Study of the REKAMLATINA Network.

Background: Multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 varies widely in its presentation and severity, with low mortality in high-income countries. In this study in 16 Latin American countries, we sought to characterize patients with MIS-C in the pediatric intensive care unit (PICU) compared with those hospitalized on the general wards and analyze the factors associated with severity, outcomes, and treatment received. Study Design: An observational ambispective cohort study was conducted including children 1 month to 18 years old in 84 hospitals from the REKAMLATINA network from January 2020 to June 2022. Results: A total of 1239 children with MIS-C were included. The median age was 6.5 years (IQR 2.5-10.1). Eighty-four percent (1043/1239) were previously healthy. Forty-eight percent (590/1239) were admitted to the PICU. These patients had more myocardial dysfunction (20% vs 4%; P < 0.01) with no difference in the frequency of coronary abnormalities (P = 0.77) when compared to general ward subjects. Of the children in the PICU, 83.4% (494/589) required vasoactive drugs, and 43.4% (256/589) invasive mechanical ventilation, due to respiratory failure and pneumonia (57% vs 32%; P = 0.01). On multivariate analysis, the factors associated with the need for PICU transfer were age over 6 years (aOR 1.76 95% CI 1.25-2.49), shock (aOR 7.06 95% CI 5.14-9.80), seizures (aOR 2.44 95% CI 1.14-5.36), thrombocytopenia (aOR 2.43 95% CI 1.77-3.34), elevated C-reactive protein (aOR 1.89 95% CI 1.29-2.79), and chest x-ray abnormalities (aOR 2.29 95% CI 1.67-3.13). The overall mortality was 4.8%. Conclusions: Children with MIS-C who have the highest risk of being admitted to a PICU in Latin American countries are those over age six, with shock, seizures, a more robust inflammatory response, and chest x-ray abnormalities. The mortality rate is five times greater when compared with high-income countries, despite a high proportion of patients receiving adequate treatment.

Kawasaki disease shock syndrome in the COVID-19 pandemic.

Multisystem inflammatory syndrome in children is a new entity in association with SARS-CoV2. Clinical features of Kawasaki disease were noted from the first reported cases of MIS-C. Before the COVID-19 pandemic, Kawasaki disease shock syndrome was considered to be a distinct and unique form of KD. We present a representative case that prove the current difficulty in clearly distinguishing MIS-C from pre-COVID-19-KDSS and emphasie the overlap of the diagnostic criteria.

Diagnostic and therapeutic caveats in Griscelli syndrome.

Griscelli syndrome (GS) is a rare autosomal recessive disease with characteristic pigment distribution, and there are currently 3 types according to the underlying genetic defect and clinical features. We present the case of a girl born from consanguineous parents who presented with predominant neurologic symptoms, silvery hair and granulomatous skin lesions. Cerebral magnetic resonance revealed diffuse white matter lesions, and central nervous system (CNS) lymphocytic infiltration was suspected. The patient underwent haematopoietic stem cell transplantation with graft failure and autologous reconstitution. She developed elevated liver enzyme with a cholestatic pattern. Multiple liver biopsies revealed centrilobular cholestasis and unspecific portal inflammation that improved with immunomodulatory treatment. She was revealed to have an impaired cytotoxicity in NK cells and a decreased expression of RAB27A. However, no variants were found in the gene. All types of GS present with pigment dilution and irregular pigment clumps that can be seen through light microscopy in hair and skin biopsy. Dermic granulomas and immunodeficiency with infectious and HLH predisposition have been described in GS type 2 (GS2). Neurologic alterations might be seen in GS type 1 (GS1) and GS type 2 (GS2), due to different mechanisms. GS1 presents with neurologic impairment secondary to myosin Va role in neuronal development and synapsis. Meanwhile, GS2 can present with neurologic impairment secondary to SNC HLH. Clinical features and cytotoxicity might aid in differentiating GS1 and GS2, especially since treatment differs.

Use of Infliximab in the Treatment of Macrophage Activation Syndrome Complicating Kawasaki Disease.

Kawasaki disease (KD) is an acute systemic vasculitis of unknown etiology. KD can be complicated with macrophage activation syndrome. The optimal treatment for this KD complication has not been established, and a variety of treatments have been used. Infliximab, a chimeric monoclonal antibody that binds tumor necrosis factor, has proved to be efficacious in IV gammaglobulin resistant KD. We present 2 cases of KD complicated with macrophage activation syndrome, including 1 patient with DiGeorge syndrome successfully treated with a combined treatment of IV gammaglobulin, corticosteroids, cyclosporine, and infliximab.

Kawasaki disease presenting with hoarseness: A multinational study of the REKAMLATINA network.

BACKGROUND: Recently, hoarseness affecting the supraglottic structure has been reported in Kawasaki disease (KD). The objective of this study was to characterize the frequency of hoarseness in acute KD patients in Latin America. METHODS: We used prospective data from the multinational Red de Enfermedad de Kawasaki en America Latina (REKAMLATINA) network. A total of 865 patients from 20 countries were enrolled during the 3 year study period. Data on hoarseness were available in 858 (99.2%) patients. The clinical and laboratory characteristics between hoarse and non-hoarse KD were compared. RESULTS: Hoarseness was documented in 100 (11.6%) patients. Hoarse patients were younger than those with KD without hoarseness (median age 18 vs 26 months; P = 0.002) and presented with lower hemoglobin (10.7 g/dL vs 11.3 g/dL; P = 0.040) and hematocrit levels (32% vs 33%, P = 0.048). CONCLUSIONS: Hoarseness was found to be prevalent as a presenting sign of acute KD in younger children. Anemia may indicate the presence of active inflammation.

A Variety of Alu-Mediated Copy Number Variations Can Underlie IL-12Rß1 Deficiency.

PURPOSE: Inborn errors of IFN-γ immunity underlie Mendelian susceptibility to mycobacterial disease (MSMD). Autosomal recessive complete IL-12Rß1 deficiency is the most frequent genetic etiology of MSMD. Only two of the 84 known mutations are copy number variations (CNVs), identified in two of the 213 IL-12Rß1-deficient patients and two of the 164 kindreds reported. These two CNVs are large deletions found in the heterozygous or homozygous state. We searched for novel families with IL-12Rß1 deficiency due to CNVs. METHODS: We studied six MSMD patients from five unrelated kindreds displaying adverse reactions to BCG vaccination. Three of the patients also presented systemic salmonellosis, two had mucocutaneous candidiasis, and one had disseminated histoplasmosis. We searched for CNVs and other variations by IL12RB1-targeted next-generation sequencing (NGS). RESULTS: We identified six new IL-12Rß1-deficient patients with a complete loss of IL-12Rß1 expression on phytohemagglutinin-activated T cells and/or EBV-transformed B cells. The cells of these patients did not respond to IL-12 and IL-23. Five different CNVs encompassing IL12RB1 (four deletions and one duplication) were identified in these patients by NGS coverage analysis, either in the homozygous state (n = 1) or in trans (n = 4) with a single-nucleotide variation (n = 3) or a small indel (n = 1). Seven of the nine mutations are novel. Interestingly, four of the five CNVs were predicted to be driven by nearby Alu elements, as well as the two previously reported large deletions. The IL12RB1 locus is actually enriched in Alu elements (44.7%), when compared with the rest of the genome (10.5%). CONCLUSION: The IL12RB1 locus is Alu-enriched and therefore prone to rearrangements at various positions. CNVs should be considered in the genetic diagnosis of IL-12Rß1 deficiency.

Giant coronary artery aneurysms complicating Kawasaki disease in Mexican children.

BACKGROUND: One of the most important complications of Kawasaki disease is the development of giant coronary aneurysms. Risk factors for their development are still not clear. METHODS: A retrospective analysis was conducted at the National Institute of Paediatrics in Mexico City, Mexico. It included all patients with a diagnosis of acute Kawasaki disease between August, 1995 and August, 2015. Clinical and laboratory findings, as well as echocardiographic measurements, were recorded. Patients with giant coronary aneurysms (z-score⩾10) were compared with the rest of the patients. A value of p<0.05 was considered statistically significant. Odds ratios and their 95% confidence intervals were calculated to define risk factors. RESULTS: During the study period, 416 patients were diagnosed with Kawasaki disease. Of them, 34 developed giant coronary aneurysms during the acute stage of the disease. In the multivariate analysis, patients younger than 1 year, those with a higher duration of illness at the time of diagnosis, and those who received additional intravenous immunoglobulin showed a significantly higher frequency of giant coronary aneurysms. CONCLUSIONS: One of the main factors associated with the development of giant coronary aneurysms was the delay in the diagnosis of Kawasaki disease. This finding highlights the importance of maintaining a high suspicion of the disease, which would enable an early diagnosis and prompt treatment and decrease the risk for developing giant coronary aneurysms.

Kawasaki Disease Complicated With Macrophage Activation Syndrome: A Systematic Review.

Macrophage activation syndrome (MAS), also known as secondary hemophagocytic lymphohistiocytosis, is a rare and potentially fatal complication of Kawasaki disease (KD). We report 2 cases, performed a literature search, and analyze the characteristics of MAS associated with KD. A total of 69 patients were evaluated, 34 reported the date of the diagnosis of MAS and KD, 6% had a diagnosis of MAS before KD, 21% had a simultaneous presentation, and 73% had the diagnosis of MAS after KD. Different treatment approaches were observed with corticosteroids administered in 87%, cyclosporine in 49%, etoposide (VP-16) in 39%, and monoclonal anti-TNF in 6% of cases. Coronary abnormalities were especially high in this group of patients (46%) and 9 patients died (13%). The persistence of fever with splenomegaly, hyperferritinemia, thrombocytopenia, and elevated aspartate aminotransferase (AST) should prompt the consideration of MAS complicating KD.

Clinical Features, Non-Infectious Manifestations and Survival Analysis of 161 Children with Primary Immunodeficiency in Mexico: A Single Center Experience Over two Decades.

PURPOSE: The hallmark of Primary immunodeficiencies (PID) is unusual infection, although other immunological non-infectious manifestations such as autoimmunity, allergy and cancer are often present. Most published reports focus on one disease or defect groups, so that a global prevalence of non-infectious manifestations of PID is hard to find. We aimed to describe the clinical features of our pediatric patients with PID, as well as the frequency and evolution of allergy, cancer and autoimmunity. METHODS: We reviewed all the available charts of patients being followed for PID from 1991 to the spring of 2012 at the National Institute of Pediatrics, Mexico City, to describe their demographic, clinical and laboratory features. Their diagnoses were established by pediatric immunologists in accordance to ESID criteria, including routine immunological workup and specialized diagnostic assays. We divided patients by decade of diagnosis to analyze their survival curves. RESULTS: There were 168 charts available, from which we excluded one duplicate and six equivocal diagnoses. We studied the charts of 161 PID patients (68% male, 86% alive), mostly from the center of the country, with a positive family history in 27% and known consanguinity in 11%. Eighty percent of the patients were diagnosed during the last decade. Current median age was 124 months; median age at onset of infections, 12 months; median age at diagnosis, 52 months; median age at death, 67.5 months. Severe infection and bleeding were the cause of 22 deaths. Eighty-six percent of all patients had at least one infection, while non-infectious manifestations had a global prevalence of 36%, namely: autoimmunity 19%, allergies 17%, and cancer 2.4%. Survival curves were not significantly different when compared by decade of diagnosis. CONCLUSIONS: Compared to other registry reports, we found a lower prevalence of antibody defects, and of associated allergy and cancer. We could only locate two isolated IgA deficiencies and four cases of cancer among our PID patients. Although antibody defects are the most prevalent group (30%), the distribution we found is similar to that reported in Iran, Kuwait, Egypt and Taiwan, with a close 27% share for phagocyte defects, and 26% for the formerly called "well-defined" syndromes. Of note, autoimmune and inflammatory complications are high among our patients with chronic granulomatous disease, as has been reported in both the United States and Japan, but not in Europe.

Intravenous immunoglobulin treatment for macrophage activation syndrome complicating chronic granulomatous disease.

OBJECTIVES: Chronic granulomatous disease is a rare phagocyte disorder characterized by an increased susceptibility to infections and inflammatory complications. We describe two patients with chronic granulomatous disease (CGD) complicated by macrophage activation syndrome (MAS) (secondary hemophagocytic lymphohistiocytosis) treated with intravenous immunoglobulin (IVIG). METHODS: A report of two cases of CGD complicated by MAS who were successfully treated with IVIG was made, and a comparison was made with ten other cases reported in the literature. RESULTS: MAS is a severe potentially fatal complication of CGD. Most cases are associated with Burkholderia cepacia and leishmaniasis infection. The treatment of these patients varies between centers, and one example is the use of the HLH-2004 protocol. IVIG could be an effective first line option for this complication in CGD patients. CONCLUSIONS: The exaggerated inflammatory response characteristic of CGD patients could play a role in the development of this complication. IVIG appears to be a safe and effective first line treatment in these patients.

Bronchiolitis Obliterans With Anti-Epiplakin Antibodies in a Boy With Paraneoplastic Pemphigus.

Paraneoplastic pemphigus is a rare and severe autoimmune blistering disease characterized by a recalcitrant and severe mucositis, and polymorphic cutaneous lesions, associated with benign and malignant neoplasms. Paraneoplastic pemphigus is caused by production of autoantibodies against various epidermal proteins involved in cell adhesion. Bronchiolitis obliterans (BO) is one of the leading causes of mortality in these patients. Recent advances have associated the presence of anti-epiplakin antibodies with the development of BO in adult patients. Here we describe the first pediatric patient in whom the association of anti-epiplakin antibodies and BO have been reported so far.

Atypical patterns of STAT3 phosphorylation in subpopulations B cells in patients with common variable immunodeficiency.

BACKGROUND: Common Variable Immunodeficiency (CVID) is a heterogeneous disorder characterized by defective B cell differentiation and antibody production. Interleukin (IL)-21 activates STAT3, a potent regulator of B cell differentiation into plasma cells. We have studied the phosphorylation of STAT3 in CVID patients and its contribution to B cells subsets. METHODS: We studied 23 CVID patients and 14 healthy donors (HD), determining pSTAT3 in naïve and memory B cells, stimulated with IL-21 at 15 and 60 min. RESULTS: pSTAT3 was increased in total (p = 0.044), naïve (p = 0.023), and memory (p = 0.001) B cells at 60 min in CVID patients compared with HD. We classified patients by the percentage of isotype-switched memory B cells. We observed an increase in pSTAT3 at 60 min in memory B cells in both CVID groups of patients (p = 0.026, p = 0.007, respectively). Interestingly, the analysis of each group individually; demonstrated that patients with decreased memory B cells exhibited an increase in pSTAT3 at 60 min (p = 0.023), while HD had an expected decrease in pSTAT3 (p = 0.045). CONCLUSION: CVID patients showed an increased atypical of pSTAT3, which could affect the differentiation of B cells. Further studies in the IL-21 pathway are necessary to understand how this alteration could promote differentiation defects in patient B cells.

Improved HUMARA for the Detection of X-Linked Agammaglobulinemia Carriers.

Background: Fragment analysis of exon 1 of the human androgen receptor, known as HUMARA, is a polymerase chain reaction (PCR)-based method for detecting X-linked agammaglobulinemia (XLA) carriers. This method takes advantage of X-chromosome inactivation (XCI) in female cells. XLA is caused by mutations in the Bruton tyrosine kinase (BTK) gene, located in Xq22.1. In this study, XCI is nonrandom or skewed in B-cells. B-cells with an active X-chromosome carrying a BTK mutation do not mature. Peripheral B-cells in XLA carriers inactivate the mutated X-chromosome. Methods: HUMARA was performed using DNA from purified B-cells and total leukocytes. DNA was digested using methylation-sensitive HhaI. The PCR of the HUMARA polymorphic marker was performed with the HhaI digested samples. The lengths of the PCR products were determined. If a suspected carrier showed skewed XCI in their B-cells, the marker length that corresponded with the length determined in the index patient indicated their carrier status. Results: HUMARA was conducted on purified B-cells; this allowed easier identification of the mutated or inactive allele, as the active allele was enzymatically digested. Analysis of 30 possible carriers using modified HUMARA corroborated that the carrier status in all samples that were heterozygous for the marker using XCI calculation for leukocytes showed a Gaussian distribution, while the carrier B-cell DNA showed a skewed XCI. Conclusion: Carrier status was successfully determined for most of the analyzed samples. B-cell enrichment resulted in precise carrier determination data, reduced the sample size, and facilitated inactive and active allele identification.

Multisystem Inflammatory Syndrome in Children in Western Countries? Decreasing Incidence as the Pandemic Progresses?: An Observational Multicenter International Cross-sectional Study.

BACKGROUND: SARS-CoV-2 variations as well as immune protection after previous infections and/or vaccination may have altered the incidence of multisystemic inflammatory syndrome in children (MIS-C). We aimed to report an international time-series analysis of the incidence of MIS-C to determine if there was a shift in the regions or countries included into the study. METHODS: This is a multicenter, international, cross-sectional study. We collected the MIS-C incidence from the participant regions and countries for the period July 2020 to November 2021. We assessed the ratio between MIS-C cases and COVID-19 pediatric cases in children <18 years diagnosed 4 weeks earlier (average time for the temporal association observed in this disease) for the study period. We performed a binomial regression analysis for 8 participating sites [Bogotá (Colombia), Chile, Costa Rica, Lazio (Italy), Mexico DF, Panama, The Netherlands and Catalonia (Spain)]. RESULTS: We included 904 cases of MIS-C, among a reference population of 17,906,432 children. We estimated a global significant decrease trend ratio in MIS-C cases/COVID-19 diagnosed cases in the previous month ( P < 0.001). When analyzing separately each of the sites, Chile and The Netherlands maintained a significant decrease trend ( P < 0.001), but this ratio was not statistically significant for the rest of sites. CONCLUSIONS: To our knowledge, this is the first international study describing a global reduction in the trend of the MIS-C incidence during the pandemic. COVID-19 vaccination and other factors possibly linked to the virus itself and/or community transmission may have played a role in preventing new MIS-C cases.

Intravenous immunoglobulin therapy for hypocomplementemic urticarial vasculitis associated with systemic lupus erythematosus in a child.

Hypocomplementemic urticarial vasculitis is a type of urticarial vasculitis with multisystemic involvement and poor prognosis, sometimes associated with systemic lupus erythematosus. Several therapies have been attempted with no consensus on an effective therapeutic regimen. Intravenous immunoglobulin has been used in severe manifestations of systemic lupus erythematosus and recently in hypocomplementemic urticarial vasculitis. We present a 7-year-old girl with hypocomplementemic urticarial vasculitis associated with systemic lupus erythematosus and pneumonia who responded favorably to intravenous immunoglobulin.

Failing to Make Ends Meet: The Broad Clinical Spectrum of DNA Ligase IV Deficiency. Case Series and Review of the Literature.

DNA repair defects are inborn errors of immunity that result in increased apoptosis and oncogenesis. DNA Ligase 4-deficient patients suffer from a wide range of clinical manifestations since early in life, including: microcephaly, dysmorphic facial features, growth failure, developmental delay, mental retardation; hip dysplasia, and other skeletal malformations; as well as a severe combined immunodeficiency, radiosensitivity, and progressive bone marrow failure; or, they may present later in life with hematological neoplasias that respond catastrophically to chemo- and radiotherapy; or, they could be asymptomatic. We describe the clinical, laboratory, and genetic features of five Mexican patients with LIG4 deficiency, together with a review of 36 other patients available in PubMed Medline. Four out of five of our patients are dead from lymphoma or bone marrow failure, with severe infection and massive bleeding; the fifth patient is asymptomatic despite a persistent CD4+ lymphopenia. Most patients reported in the literature are microcephalic females with growth failure, sinopulmonary infections, hypogammaglobulinemia, very low B-cells, and radiosensitivity; while bone marrow failure and malignancy may develop at a later age. Dysmorphic facial features, congenital hip dysplasia, chronic liver disease, gradual pancytopenia, lymphoma or leukemia, thrombocytopenia, and gastrointestinal bleeding have been reported as well. Most mutations are compound heterozygous, and all of them are hypomorphic, with two common truncating mutations accounting for the majority of patients. Stem-cell transplantation after reduced intensity conditioning regimes may be curative.

Catastrophic Kawasaki disease or juvenile Polyarteritis nodosa?

OBJECTIVE: Juvenile Polyarteritis nodosa (PAN) and Kawasaki Disease (KD) are disseminated vasculitides of unknown cause affecting small- and medium-sized vessels in children. We present an unusually severe case that fulfilled criteria for both KD and PAN. The diagnosis, overlapping clinical features, and treatment options for the 2 diseases are discussed. METHODS: A 3-year-old girl with systemic vasculitis is presented. We compare our case to 4 other cases reported in the literature which presented with a similar diagnostic dilemma. A review of the medical literature and a qualitative analysis of the diseases were performed, with emphasis on overlapping features, atypical cases, and treatment options. RESULTS: Many features of KD and PAN are shared; however, there are some clinical features that could help differentiate one from the other. Fever, weight loss, rash, abdominal pain, arthritis, coronary arteritis, peripheral gangrene, anemia, leukocytosis, thrombocytosis, and elevated C-reactive protein are among many of the features that are shared by both diseases. However, KD also has unique clinical features that include conjunctivitis, changes in the lips and mouth, desquamation of the fingertips, and gallbladder hydrops, whereas renal involvement in KD is rare. CONCLUSIONS: Occasionally juvenile PAN and KD share clinical manifestations, and when they do, it may be impossible to differentiate between them. Treatment should be directed according to the severity and persistence of these clinical manifestations.