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.

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 product were determined. If a suspected carrier showed skewed XCI in 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.

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.

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.

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.

Expanding the clinical features of autoinflammation and phospholipase Cγ2-associated antibody deficiency and immune dysregulation by description of a novel patient

BACKGROUND

Autoinflammation and phospholipase Cγ2-associated antibody deficiency and immune dysregulation (APLAID) is an exceedingly rare monogenic autoinflammatory disease. To date, only five cases have been reported with four distinct pathogenic mutations.

OBJECTIVES

We present a novel case of APLAID, corroborated by molecular analysis, with newly described clinical findings including central nervous system vasculitis (CNSV); and distinctive histopathological characteristics that may expand our knowledge of this rare disease's phenotype.

METHODS

This is a case report presentation of a 3-year-old boy, seen at a reference paediatric hospital in Mexico. His parents authorized the use of his clinical information and photographs.

RESULTS

A 3-day-old boy presented to the emergency department with a vesiculo-pustular rash that resolved within 1 week. Two months later, he developed widespread papules and pseudovesicles that evolved into infiltrated plaques. He also had periodical flares of conjunctivitis, diarrhoea and erythematous blistering acral plaques triggered by upper respiratory infections. By the age of 10 months, he experienced seizures and CNSV. Laboratory work-up showed mild neutropenia, decreased serum levels of immunoglobulins and B-cell lymphopenia. A skin biopsy revealed a dense, perivascular and interstitial histiocytic and granulomatous infiltrate, with palisading granulomas, and leucocytoclastic vasculitis with karyorrhexis. APLAID syndrome was confirmed by Sanger sequencing of PLCG2 gene [heterozygous genotype LRG_376t1:c.2543T>C or p.(Leu848Pro)].

CONCLUSIONS

Presence of CNSV has not been previously described in APLAID, however as the number of reported patients with APLAID is very small, it is possible that the overall spectrum of clinical manifestations has not been completely elucidated. The herein identified p.(Leu848Pro) variant was also documented in a Portuguese patient, suggesting that it could be a PLCG2 gene 'hot-spot'.

A Variety of Alu-Mediated Copy Number Variations Can Underlie IL-12Rβ1 Deficiency

PURPOSE

Inborn errors of IFN-γ immunity underlie Mendelian susceptibility to mycobacterial disease (MSMD). Autosomal recessive complete IL-12Rβ1 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-12Rβ1-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-12Rβ1 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-12Rβ1-deficient patients with a complete loss of IL-12Rβ1 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-12Rβ1 deficiency.

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.

Subcutaneous immunoglobulin for the treatment of deep morphoea in a child

Morphoea, also known as localized scleroderma, is a disorder characterized by excessive collagen deposition leading to thickening of the dermis and/or subcutaneous tissues. Intravenous IgG therapy has induced improvement in some fibrotic conditions. The primary indication for subcutaneous IgG (SCIG) is in primary immunodeficiency disorders as replacement therapy; however, recently there has been considerable interest in SCIG as an immunomodulatory agent. We report an 11-year-old girl with deep morphoea who was successfully treated with SCIG.

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.

Respuesta a la carta al Editor

Le agradecemos por darnos la oportunidad de contestar a la carta “Magnitud del tamaño del efecto y su importancia en la investigación pediátrica”1 del Dr. Tomás Caycho. También quisiéramos agradecer por las observaciones y comentarios del Dr. Caycho, a través de los cuales se señala la importancia y necesidad de reportar tamaño de efecto en los resultados de análisis estadístico en las investigaciones y de nuestro trabajo: “Calidad de vida de los pacientes con inmunodeficiencias primarias de anticuerpos”2 publicado en esta revista.

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.

DOCK8 deficiency impairs CD8 T cell survival and function in humans and mice

In humans, DOCK8 immunodeficiency syndrome is characterized by severe cutaneous viral infections. Thus, CD8 T cell function may be compromised in the absence of DOCK8. In this study, by analyzing mutant mice and humans, we demonstrate a critical, intrinsic role for DOCK8 in peripheral CD8 T cell survival and function. DOCK8 mutation selectively diminished the abundance of circulating naive CD8 T cells in both species, and in DOCK8-deficient humans, most CD8 T cells displayed an exhausted CD45RA(+)CCR7(-) phenotype. Analyses in mice revealed the CD8 T cell abnormalities to be cell autonomous and primarily postthymic. DOCK8 mutant naive CD8 T cells had a shorter lifespan and, upon encounter with antigen on dendritic cells, exhibited poor LFA-1 synaptic polarization and a delay in the first cell division. Although DOCK8 mutant T cells underwent near-normal primary clonal expansion after primary infection with recombinant influenza virus in vivo, they showed greatly reduced memory cell persistence and recall. These findings highlight a key role for DOCK8 in the survival and function of human and mouse CD8 T cells.

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.

Chronic granulomatous disease associated with atypical Kawasaki disease

Chronic granulomatous disease (CGD) is an infrequent inherited disorder characterized by recurrent infections and abnormal granuloma formation. Patients with CGD have an exuberant inflammatory response and an increased risk of developing autoimmunity. We present the case of a 1-year-old boy with CGD who developed several of the characteristic clinical features of Kawasaki Disease. His illness responded to intravenous immunoglobulin, aspirin, and corticosteroids.

Corticosteroid therapy for refractory infections in chronic granulomatous disease: case reports and review of the literature

BACKGROUND

Chronic granulomatous disease (CGD) is a primary phagocyte immunodeficiency. It is often accompanied by an exuberant and aberrant inflammatory response, with granulomata and obstruction of the gastrointestinal and genitourinary tracts and inflammatory bowel disease. Although corticosteroids are successful in managing the obstructive and inflammatory disorders of CGD, they are not ordinarily used for the management of infection because of the possibility of further compromising the patient's immune system.

OBJECTIVES

To discuss the pros and cons of the use of corticosteroids for the treatment of infections in CGD.

METHODS

We describe 2 patients with CGD and refractory infections who were successfully treated with systemic corticosteroids in addition to antimicrobial agents. We also review the medical literature in which corticosteroids have been used for CGD infection.

RESULTS

Our cases add to 3 other reports in which antibiotics and corticosteroids were used successfully in patients with CGD. However, in the presence of a potential pathogen, notably, aspergilla, corticosteroids may mask or favor dissemination of the fungus, especially in adults.

CONCLUSIONS

Corticosteroids may play an important adjunctive role in CGD refractory infections.

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.