Expression of autoimmunity in the transition from childhood to adulthood: role of cytokines and gender

Complex patterns on HEp-2 indirect immunofluorescence assay in a large sample referred for anti-cell autoantibodies detection

Introduction

The combination of patterns is a frequent and challenging situation in the daily laboratory routine of autoantibodies testing using HEp-2 cells indirect immunofluorescence assay (HEp-2-IFA). Recently, the Brazilian Consensus on Autoantibodies (BCA) named these combinations as complex patterns (CPs) and organized them into 3 subtypes: multiple, mixed, and composite. This study aimed to describe the most frequent combinations of HEp-2-IIF patterns according to this new nomenclature.

Methods

Routine HEp-2-IFA results reported in January and June 2017 were reviewed using the new BCA classification. Visual pattern recognition was performed by experts on HEp-2-IFA readings, using the International Consensus on Antinuclear Antibodies (ANA) Patterns (ICAP) and BCA recommendations.

Results

54,990 serum samples from different patients were tested for ANA-HEp-2, and 11,478 (20.9%) were positive at a titer ≥ 1/80. Among these positive samples, 1,111 (9.7%) displayed CPs, divided into 95 different combinations. A higher proportion of CPs was observed in the pediatric age group. Multiple, mixed, and composite patterns were present in 85.3, 5.4, and 9.5% of the samples, respectively. In the multiple/mixed pattern group (n=1,005), double, triple, and quadruple combinations (ICAP/BCA codes) were observed in 97.7%, 2.2%, and 0.1%, respectively. The double nuclear pattern was the most prevalent combination observed (67.6%). The most common CPs registered were AC-4 (nuclear fine speckled) + AC-6,7 (nuclear discrete dots) (n=264); AC-2 (nuclear dense fine speckled) + AC-6,7 (n=201); AC-4+AC-8,9,10 (nucleolar) (n=129); and AC-3 (centromere)+AC-4 (n=124). All of these combinations were in the multiple subgroup.

Conclusion

Almost 10% of positive results in the HEp-2 procedure displayed CPs. Among the 3 subtypes of CPs proposed, the multiple pattern was the most prevalent, especially in the pediatric population. The AC-4, AC-2, and AC-6,7 were the most prevalent single patterns observed in the combinations described in this study. There was a significant association between age and the prevalence of most combined patterns. The AC-4+AC-6,7 combination was the most prevalent complex pattern detected regardless of the age group. The AC-2+AC-6,7 was more prevalent in younger individuals. The concepts involved in the CPs definition should add value to the reading and interpretation of the HEp-2-IIF assay.

Measuring attack on self: The need for field-friendly methods development and research on autoimmunity in human biology

BACKGROUND

Autoimmune and inflammatory disorder (AIID) prevalence appears to be increasing in all but the world's poorest regions and countries. Autoimmune diseases occur when there is a breakdown in processes that regulate inflammation and self-recognition by immune cells. Very few field-based studies have been conducted among Indigenous populations and underserved communities with limited access to medical care. This is due, in part, to the fact that autoimmune diseases are difficult to diagnose, even in clinical settings. In remote field settings these difficulties are compounded by the absence of infrastructure necessary for sample storage and analysis, and the lack of hospital/clinic access for more invasive diagnostic procedures. Because of these limitations, little is known about the prevalence of autoimmunity outside wealthy regions and clinical settings.

AIMS

The present paper discusses why AIID are of critical importance in human biology research and why more work needs to be devoted to validating, testing, and utilizing methods for detecting autoantibodies and other biomarkers related to autoimmunity in field-friendly, minimally invasively-collected samples. This paper reviews some of the methods used to diagnose AIIDs in clinical settings, and highlights methods that have been used in studies within human biology and related fields, emphasizing the invasiveness of specific methods and their feasibility in remote field settings.

DISCUSSION AND CONCLUSIONS

Risk for AIID is affected by several reproductive, dietary, environmental, and genetic factors. Human biologists have unique perspectives that they can bring to autoimmunity research, and more population-based studies on autoimmunity are needed within these and related fields.

Clustered Cardiovascular Risk Factors Are Associated with Inflammatory Markers in Adolescents

BACKGROUND

Clusters of cardiovascular risk (CVR) factors are associated with an increased risk of developing cardiovascular diseases (CVDs). This cross-sectional study assessed the associations between classic CVR factor clusters and inflammatory markers in Brazilian adolescents.

METHODS

Measurements included anthropometric, clinical and biochemical parameters and selected inflammatory markers in 487 adolescents (236 boys/251 girls; 12.06 ± 1.41 years).

RESULTS

After stratifying the population by gender and adjusting for potential confounding variables, principal component analysis was performed and it produced 5 independent components in both genders: adiposity, glucose metabolism, blood pressure, high-density lipoprotein (HDL)/triacylglycerols (TG), and cholesterol/low-density lipoprotein. Glucose metabolism was inversely associated with interleukin-1β (IL-1β) in both genders (r = -0.026; r = -0.021); blood pressure was inversely associated with tumor necrosis factor alpha (TNF-α) in girls (r = -0.046); HDL/TG was positively associated with interleukin-6 in girls (r = 0.012), with IL-1β (r = 0.010) TNF-α (r = 0.045) in boys, and inversely associated with adiponectin in both genders (r = -0.015; r = -0.013).

CONCLUSION

The results suggest that lipid metabolism alterations, as potential early events in the development of CVDs, have a strong link to the inflammatory process, in contrast to other clusters of risk factors.

Musculoskeletal pain in schoolchildren across puberty: a 3-year follow-up study

BACKGROUND

Chronic Musculoskeletal Pain (MSP) in children can be due to non-inflammatory conditions, such as the benign joint hypermobility syndrome (BJHS) or idiopathic MSP (IMSP). Aim of the study was to evaluate type and persistence of MSP in a cohort of schoolchildren with MSP followed for 3 years, in order to identify the main risk factors.

METHODS

Healthy schoolchildren, aged 8-13 years, underwent a general and rheumatologic examination, focusing on presence of chronic MSP, defined as continuous or recurrent pain lasting more than 3 months and heavily interfering with daily life activities, presence of generalized joint hypermobility, the body mass index and the pubertal stage. All symptomatic subjects were re-evaluated 3 years later with the same methods.

RESULTS

Seventy of the 88 symptomatic subjects of the initial cohort of 289 were re-evaluated 3 years later. Of these, 38 (54.3 %) still presented MSP, including 19 with BJHS and 19 with IMSP. Main symptoms were lower limbs arthralgia and myalgia. MSP persisted more in females than in males (p = 0.038) and in pubertal rather than pre-pubertal subjects (p = 0.022); these subjects recovered significantly more both from BJHS (p = 0.004) and IMSP (p = 0.016). Gender did not influence the distribution of MSP according to pubertal stage.

CONCLUSIONS

Female gender, BJHS and pubertal stage are important risk factors for persistence of MSP. Further studies are needed to evaluate the natural history of MSP towards adulthood and the role of the pubertal age.

Prevalence of antinuclear antibodies in schoolchildren during puberty and possible relationship with musculoskeletal pain: a longitudinal study

OBJECTIVE

The role of antinuclear antibodies (ANA) in children has still to be elucidated. The aim of our study was to evaluate the prevalence and persistence of ANA in schoolchildren during the puberty switch, and the possible relationship with chronic noninflammatory musculoskeletal pain (MSP).

METHODS

Children aged 8-13 years and attending 4 public schools underwent a clinical examination, focusing on pubertal stage and presence of chronic noninflammatory MSP. Laboratory tests to determine the autoantibody-profile were also performed. Subjects with ANA positivity (titer ≥ 1:80) and/or chronic noninflammatory MSP were re-evaluated 3 years later.

RESULTS

Two hundred sixty-one subjects enrolled in the study and 12.3% were ANA-positive, equally distributed in terms of sex and pubertal status. Three years later, in the group of patients studied for chronic noninflammatory MSP (n = 67), ANA positivity significantly increased from 13.4% to 44.8%. In the ANA-positive cohort at baseline (n = 28), 92.9% of subjects were confirmed as being ANA-positive with a significantly increased titer. No association between ANA positivity and chronic noninflammatory MSP was found.

CONCLUSION

ANA prevalence and titers increase during puberty, especially in females, but have no relationship with chronic noninflammatory MSP. This finding may be related to the complex hormonal changes during the puberty switch period and opens new insights into autoimmunity.

Central role of the gut epithelial barrier in the pathogenesis of chronic intestinal inflammation: lessons learned from animal models and human genetics

The gut mucosa is constantly challenged by a bombardment of foreign antigens and environmental microorganisms. As such, the precise regulation of the intestinal barrier allows the maintenance of mucosal immune homeostasis and prevents the onset of uncontrolled inflammation. In support of this concept, emerging evidence points to defects in components of the epithelial barrier as etiologic factors in the pathogenesis of inflammatory bowel diseases (IBDs). In fact, the integrity of the intestinal barrier relies on different elements, including robust innate immune responses, epithelial paracellular permeability, epithelial cell integrity, as well as the production of mucus. The purpose of this review is to systematically evaluate how alterations in the aforementioned epithelial components can lead to the disruption of intestinal immune homeostasis, and subsequent inflammation. In this regard, the wealth of data from mouse models of intestinal inflammation and human genetics are pivotal in understanding pathogenic pathways, for example, that are initiated from the specific loss of function of a single protein leading to the onset of intestinal disease. On the other hand, several recently proposed therapeutic approaches to treat human IBD are targeted at enhancing different elements of gut barrier function, further supporting a primary role of the epithelium in the pathogenesis of chronic intestinal inflammation and emphasizing the importance of maintaining a healthy and effective intestinal barrier.

The role of the innate and adaptive immune system in pediatric inflammatory bowel disease

Recent translational studies have provided new insights into the pathogenesis of pediatric-onset inflammatory bowel disease. Registry studies have identified distinct clinical phenotypes with increasing age of onset; this has led to a revision of the clinical phenotyping system, now termed the Paris classification system. It is recognized that there are infantile (age, <1 years), very early onset (VEO) (age, 1-10 years), and early onset (age, 10-17 years) forms of disease. Rare genetic mutations affecting antimicrobial and anti-inflammatory pathways have been discovered in infantile and VEO forms, although genetic pathways identified in early onset disease have been similar to adult-onset inflammatory bowel disease. An increasing incidence in the infantile and VEO forms has suggested an important environmental influence. This is likely ultimately expressed through alterations in the enteric flora (dysbiosis) and dysregulated immune responses to the flora, which are recognized as a critical trigger for mucosal inflammation. These data should ultimately guide new pathogenic models of disease, which will inform both therapy in individual patients and disease prevention in their at-risk family members.

The roles of the immune system in women's reproduction: evolutionary constraints and life history trade-offs

Life history theory posits that, as long as survival is assured, finite resources are available for reproduction, maintenance, and growth/storage. To maximize lifetime reproductive success, resources are subject to trade-offs both within individuals and between current and future investment. For women, reproducing is costly and time-consuming; the bulk of available resources must be allocated to reproduction at the expense of more flexible systems like immune function. When reproducing women contract infectious diseases, the resources required for immune activation can fundamentally shift the patterns of resource allocation. Adding to the complexity of the reproductive-immune trade-offs in women are the pleiotropic effects of many immune factors, which were modified to serve key roles in mammalian reproduction. In this review, we explore the complex intersections between immune function and female reproduction to situate proximate immunological processes within a life history framework. After a brief overview of the immune system, we discuss some important physiological roles of immune factors in women's reproduction and the conflicts that may arise when these factors must play dual roles. We then discuss the influence of reproductive-immune trade-offs on the patterning of lifetime reproductive success: (1) the effect of immune activation/infectious disease on the timing of life history events; (2) the role of the immune system, immune activation, and infectious disease on resource allocation within individual reproductive events, particularly pregnancy; and (3) the role of the immune system in shaping the offspring's patterns of future life history trade-offs. We close with a discussion of future directions in reproductive immunology for anthropologists.

The multiple sclerosis trait and the development of multiple sclerosis: Genetic vulnerability and environmental effect

The remarkably low rate of concordance of multiple sclerosis (MS) in monozygotic twins has never been fully explained but it implies the possibility of a systemic condition called the multiple sclerosis trait (MST), which is quite different from asymptomatic MS. It results from the action of an antigenic challenge on the immune system of a genetically vulnerable person that does not cause damage to the nervous parenchyma; it may never evolve into the disease MS. A subsequent environmental viral-antigenic event in some MST-carriers can change the trait into the disease. This event could be an infection, which need not be symptomatic, or a vaccination. The MS may become symptomatic, remain asymptomatic, or manifested only by lesions visible by MRI. It is likely that the development of the MST, called activation, occurs early in life, while the transition from MST to MS, called acquisition, takes place at puberty in most patients. Differences in prevalence between pre-puberal migrants, and the locally born children of migrants, and their population of origin may also be explained by the MST.

Hormonal modulation of B cell development and repertoire selection

Systemic lupus erythematosus is an autoimmune disorder characterized by the production of pathogenic autoantibodies, primarily to nuclear antigens. The etiology of SLE is not entirely understood, but it is well-appreciated that multiple factors such as genetics and environment contribute to disease progression and pathogenesis. There is also convincing evidence that gender plays an import role in SLE since the incidence of disease occurs with a female to male ratio of 9:1. While it is plausible that some sex-linked genes may contribute to the genetic predisposition for the disease, other likely culprits for this gender bias are the sex hormones estrogen and prolactin. The data implicating estrogen and prolactin in SLE, until recently, were largely circumstantial. However, within the last few years, data collected from both human and mouse studies have provided compelling evidence that alterations in sex hormone levels can alter tolerance of autoreactive B cells and exacerbate disease. In this review, we will discuss recent data demonstrating a role for estrogen and prolactin in SLE and the effect of these hormones on B cell maturation, selection and activation.