Growth and puberty in children with juvenile idiopathic arthritis

Are the nutritional status and growth parameters of children with juvenile idiopathic arthritis akin to their healthy peers? A single-center experience

OBJECTIVE

Proper nutrition is a significant contributor to growth achievement in patients with juvenile idiopathic arthritis (JIA). In this study, the aim was to analyze the growth parameters and nutritional status of children with JIA and then compare them with their healthy peers.

METHODS

A cross-sectional study was conducted with 54 patients with JIA and the same number of healthy peers. Growth parameter z-scores and nutrient distributions were analyzed and compared with a control group and among disease subgroups.

RESULTS

While the average height in the control group was significantly greater than in the patient group, there was similarity in terms of body weight and body mass index (BMI) (P < 0.001, P = 0.33, P = 0.14, respectively). Body weight and BMI z-scores of patients with high disease activity at the most recent visit were significantly lower (P = 0.03, P = 0.01, respectively). Both groups had similar energy and protein requirement-meeting percentages (P = 0.62, P = 0.51). JIA atients had higher carbohydrate intake (P = 0.04), and fat intake was higher in controls (P = 0.02). Energy obtained from junk food was higher in patients with entesitis-related arthritis (ERA) compared to oligoarticular JIA and polyarticular JIA (P = 0.03). Micronutrient intake in the ERA group was significantly lower for vitamin E, C, and folate (P = 0.02, P = 0.03, P < 0.001).

CONCLUSION

In our cohort, patients had a lower height score. As they have a diet characterized by adequate energy/protein, carbohydrate, and high fat intake, this may be a reflection of disease activity. Although some of the micronutrient intakes were less than normal in both groups, significant deficiencies were identified in the ERA group.

Minipuberty in Daughters of Women with Hypothyroidism during Pregnancy

Minipuberty is a term describing transient postnatal activation of the hypothalamic-pituitary-gonadal axis, likely playing an important role in the postnatal growth of female genital organs and breasts. Unlike infant boys, there are no data concerning the impact of gestational hypothyroidism on the course of minipuberty in infant girls. Therefore, the aim of the current study was to investigate the reproductive axis and genital organs in daughters of women with thyroid hypofunction during pregnancy. The study population included three matched groups of infant girls: offspring of women with thyroid hypofunction non-substituted or inadequately treated during gestation (group 1), descendants of women adequately substituted throughout pregnancy (group 2), and daughters of healthy women (group 3). Salivary concentrations of estradiol, progesterone, 17-hydroxyprogesterone, and androgens (testosterone, androstenedione, and dehydroepiandrosterone sulfate) and urine levels of gonadotropins were measured monthly from month 1 to month 6, once every two months between postnatal months 6 and 12, and once every three months between postnatal months 12 and 18. During each visit, we also determined ovarian volume, uterine length, and breast diameter. Concentrations of FSH, LH, and estradiol were lowest in group 1, and this group was also characterized by the shortest detection period for gonadotropins and estradiol. These differences were paralleled by differences in ovarian volume, uterine length, and breast diameter. There were no differences between groups 2 and 3 in levels of both hormones and in the size of the measured structures. The obtained results seem to indicate that non-substituted or inadequately substituted hypothyroidism during pregnancy may impair the course of minipuberty in the female offspring.

Identifying factors associated with substantially reduced adult height in patients with juvenile idiopathic arthritis: a retrospective cohort study

BACKGROUND

Juvenile idiopathic arthritis (JIA), an autoimmune disease affecting children or adolescents and causing joint or systemic symptoms, reportedly has a negative effect on the patients' body height. This study aimed to identify factors attributable to substantially reduced adult height (SRAH) in JIA patients.

METHODS

This single-center retrospective cohort study included patients from 2009 to 2019 in Taiwan. We collected JIA patients aged > 18 years at enrollment with a definite diagnosis and undergoing regular outpatient clinic follow-up or disease remission. Target height difference (THD), defined by adult height minus mid-parental height, was calculated for each patient. The calculation results yielded two groups, of which positive THD was defined as the optimal height (OH group) and those with THD below two standardized deviations as the SRAH group. Descriptive statistics and logistic regression analysis were used to analyze the data.

RESULTS

Of 92 JIA patients, 57 and 12 were in the OH and the SRAH groups. Earlier disease onset, especially before the six-year-old, was noted in the SRAH group (p = 0.026). The distribution of JIA subtypes differed significantly between the two groups (p < 0.001); enthesis-related arthritis was the commonest subtype in the OH group, and systemic JIA was the commonest in the SRAH group. Half of the patients in the SRAH group had an active disease status at enrollment, which was higher than the OH group (50.0% vs. 21.1%, p = 0.066). More patients in the SRAH group had received orthopedic surgery due to JIA (25% vs. 3.5%, p = 0.034). Multiple logistic regression analysis showed that SRAH was independently related to systemic JIA (OR = 37.6, 95%CI 1.2-1210.5; p = 0.041).

CONCLUSION

The subtype of systemic JIA, with its characteristics of early disease onset and active disease status, was the essential factor that significantly impacted adult height.

Causality between Sex Hormones and Bone Mineral Density in Childhood: Age- and Tanner-Stage-Matched Sex Hormone Level May Be an Early Indicator of Pediatric Bone Fragility

This study aimed to investigate the impact of hypogonadism on bone mineral density (BMD) in children and adolescents with chronic diseases to determine the relationship between sex hormones and BMD. This retrospective study included 672 children and adolescents with chronic diseases such as hemato-oncologic, rheumatoid, gastrointestinal, and endocrinologic diseases. The relationship between the sex- and Tanner-stage-matched Z-scores for sex hormones and the sex- and age-matched lumbar spine BMD (LSBMD) Z-scores was evaluated. Adjustments were made for confounders such as underlying diseases, age at diagnosis, and age- and sex-matched body mass index Z-scores. Patients had a mean LSBMD Z-score of -0.55 ± 1.31. In the multivariate regression analysis, male testosterone showed a positive association with the LSBMD Z-score (p < 0.001), whereas female estradiol, luteinizing hormone, and follicular-stimulating hormone showed no significant association with the LSBMD Z-scores. In the male group, the testosterone level was associated with LSBMD Z-scores > -1.0 (p < 0.001), > -2.0 (p < 0.001), and > -3.0 (p = 0.002), while the estradiol level was associated with LSBMD Z-scores > -2.0 (p = 0.001) and > -3.0 (p = 0.002) in the female group. In conclusion, sex hormones are associated with BMD in children and adolescents with chronic diseases. Therefore, various measures may be necessary to predict future skeletal problems and improve bone health in these patients.

Presentation of enthesitis-related arthritis and juvenile-onset spondyloarthritis: a cross-sectional study in a pediatric and adult clinic

BACKGROUND

Juvenile idiopathic arthritis (JIA) comprises a whole spectrum of chronic arthritis starting before 16 years of age. The study aims to explore the clinical and demographic descriptors, treatment, and disease progression of enthesitis-related arthritis (ERA) in comparison with juvenile-onset spondyloarthritis (SpA).

METHODS

Cross-sectional analysis of consecutive patients in two dedicated clinics, with a single visit and retrospective case-notes review. Arthritis, enthesitis and sacroiliitis were evaluated by scoring disease activity and damage. Continuous variables were reported by median, interquartile range; categorical variables were reported by the frequency comparison of the two groups.

RESULTS

Thirty-three cases were included, being 23 (69.7%) with ERA. The median age at diagnosis was 12.5 y (SpA) vs. 9 y (ERA) (p < 0.01); the time from symptom onset to diagnosis was 5.5 y (SpA) vs. 1.5 y (ERA) (p < 0.03). In both groups, the predominant presentation was a single joint or < 5 lower limb joints and asymmetric involvement, with a high frequency of enthesitis. There was a higher frequency of mid-tarsal and ankle synovitis in the ERA group and hip involvement in those with SpA. The comparison of the frequency of spine symptoms at presentation, 30% SpA vs. 21.7% ERA (p = 0.7), was not significant, and radiographic progression to spinal involvement occurred in 43.5% of ERA patients. The median time for spinal progression and age at onset was 2.2 and 12 y for ERA, and 4 and 16.5 y for SpA, respectively. Activity and damage scores were not significantly different between the groups. Treatment comparison resulted in 91.3% of ERA and 100% SpA being treated, predominantly with NSAIDs in both groups, followed by DMARDs and biologics, with a higher frequency of biologics in SpA.

CONCLUSION

The main differences were the late diagnoses of SpA, and the hip and spine involvement, with higher frequency of biologic treatment in juvenile-onset SpA compared to ERA.

Gut microbiota in regulation of childhood bone growth

Childhood stunting and wasting, or decreased linear and ponderal growth associated with undernutrition, continue to be a major global public health challenge. Although many of the current therapeutic and dietary interventions have significantly reduced childhood mortality caused by undernutrition, there remain great inefficacies in improving childhood stunting. Longitudinal bone growth in children is governed by different genetic, nutritional and other environmental factors acting systemically on the endocrine system and locally at the growth plate. Recent studies have shown that this intricate interplay between nutritional and hormonal regulation of the growth plate could involve the gut microbiota, highlighting the importance of a holistic approach in tackling childhood undernutrition. In this review, I focus on the mechanistic insights provided by these recent advances in gut microbiota research and discuss ongoing development of microbiota-based therapeutics in humans, which could be the missing link in solving undernutrition and childhood stunting.

The role of radiography in diagnosing, monitoring and prognosing juvenile idiopathic arthritis

The current role of conventional radiography in the diagnosis, monitoring and prognosis of juvenile idiopathic arthritis (JIA) is reviewed, as its role has changed with the increasing use of ultrasound and magnetic resonance imaging, as well as with the introduction of biological drugs. Conventional radiography does not play an important role in the diagnosis of JIA, as this is based on history, clinical examination and laboratory findings. The main role of conventional radiography is in the detection and monitoring of growth disorders and chronic structural and morphological changes of the affected joints and bones, in addition to helping with the differential diagnosis of conditions that mimic JIA. Radiographic changes of the joints depend on the age of the child, the type and duration of arthritis and the specific joints affected. There are no standard protocols for arthritis monitoring and most indications for imaging are based on individual case-by-case decisions. The development of degenerative joint changes is considered a poor predictive factor, but there are no clear studies that more precisely define the predictive value of radiographic changes. Conventional radiography remains an important imaging modality in narrowing the differential diagnosis and in evaluating growth disorders and the developing destructive joint changes.

Temporomandibular involvement in children and adolescents with juvenile idiopathic arthritis: a 2-year prospective cohort study

This study aimed to clinically evaluate temporomandibular joint (TMJ) involvement in juvenile idiopathic arthritis (JIA) and the ability to identify and/or predict development of TMJ-deformities over time using cone beam computed tomography (CBCT). The predictive value of self-reported TMJ pain was also assessed. A prospective longitudinal cohort study comprising 54 children with JIA, 39 girls and 15 boys, was performed. All children had active disease at baseline, 50% with the subtype oligoarthritis. Repeated clinical orofacial and CBCT examinations were performed over a two-year period. At baseline, 39% had radiographic TMJ deformities (24% unilateral, 15% bilateral), at 2-year follow-up, 42% (p > 0.05). Both progressing and improving TMJ deformities were observed. An association was found between TMJ-deformities and self-reported TMJ pain at baseline (p = 0.01). Maximum unassisted mouth opening (MUO) was smaller for children with TMJ-deformities (p < 0.05). The prevalence of palpatory muscle pain was high (48-59%) but not predictive of development of TMJ-deformities. TMJ noises increased over time and crepitations were associated with TMJ-deformities (p < 0.05). In conclusion, in children with JIA, self-reported TMJ pain and dysfunction were common and predictive of TMJ deformities. TMJ deformities were associated with smaller MUO and palpatory TMJ pain as well as crepitations. Trial registration. ClinicalTrials.gov Protocol id: 2010/2089-31/2.

Prospective study to characterize adalimumab exposure in pediatric patients with rheumatic diseases

BACKGROUND

In pediatric rheumatic diseases (PRD), adalimumab is dosed using fixed weight-based bands irrespective of methotrexate co-treatment, disease activity (DA) or other factors that might influence adalimumab pharmacokinetics (PK). In rheumatoid arthritis (RA) adalimumab exposure between 2-8 mg/L is associated with clinical response. PRD data on adalimumab is scarce. Therefore, this study aimed to analyze adalimumab PK and its variability in PRD treated with/without methotrexate.

METHODS

A two-center prospective study in PRD patients aged 2-18 years treated with adalimumab and methotrexate (GA-M) or adalimumab alone (GA) for ≥ 12 weeks was performed. Adalimumab concentrations were collected 1-9 (maximum concentration; Cmax), and 10-14 days (minimum concentration; Cmin) during ≥ 12 weeks following adalimumab start. Concentrations were analyzed with enzyme-linked immunosorbent assay (lower limit of quantification: 0.5 mg/L). Log-normalized Cmin were compared between GA-M and GA using a standard t-test.

RESULTS

Twenty-eight patients (14 per group), diagnosed with juvenile idiopathic arthritis (71.4%), non-infectious uveitis (25%) or chronic recurrent multifocal osteomyelitis (3.6%) completed the study. GA-M included more females (71.4%; GA 35.7%, p = 0.13). At first study visit, children in GA-M had a slightly longer exposure to adalimumab (17.8 months [IQR 9.6, 21.6]) compared to GA (15.8 months [IQR 8.5, 30.8], p = 0.8). Adalimumab dosing was similar between both groups (median dose 40 mg every 14 days) and observed DA was low. Children in GA-M had a 27% higher median overall exposure compared to GA, although median Cmin adalimumab values were statistically not different (p = 0.3). Cmin values ≥ 8 mg/L (upper limit RA) were more frequently observed in GA-M versus GA (79% versus 64%). Overall, a wide range of Cmin values was observed in PRD (0.5 to 26 mg/L).

CONCLUSION

This study revealed a high heterogeneity in adalimumab exposure in PRD. Adalimumab exposure tended to be higher with methotrexate co-treatment compared to adalimumab monotherapy although differences were not statistically significant. Most children showed adalimumab exposure exceeding those reported for RA with clinical response, particularly with methotrexate co-treatment. This highlights the need of further investigations to establish model-based personalized treatment strategies in PRD to avoid under- and overexposure.

TRIAL REGISTRATION

NCT04042792 , registered 02.08.2019.

GH therapy in children with juvenile idiopathic arthritis: a four-decade review

Chronic inflammatory conditions, such as juvenile idiopathic arthritis, are associated with growth failure. Growth failure appears to be correlated with both the effects of inflammation and negative effects of glucocorticoids (used as therapeutic option) on the growth hormone axis and locally on the growth plate and bone metabolism. In the last decade, the introduction of biologics has changed the disease course regarding consequences and outcomes. Anyway in some cases, treatment with biologics has failed in restoring normal growth in patients with juvenile idiopathic arthritis; in contrast, several studies have reported improved height velocity and growth rate in patients with juvenile idiopathic arthritis treated with growth hormone. This study aimed to evaluate the impact of growth hormone treatment on the growth and pubertal development in juvenile idiopathic arthritis patients through a narrative review of the literature over the last four decades.

Intestinal flora and linear growth in children

The gut microbiota plays a critical role in human growth and development as well as the regulation of human pathophysiological processes. According to research, the gut microbiota controls the host's growth and development in areas such as nutrition, metabolism, endocrine hormones, and immune modulation. The human gut microbiota has an important role in child and adolescent growth, especially when nutritional conditions are poor. In this review, we focus on recent findings about the gut microbiota's influence on child growth, including the relationship between the gut microbiota and linear growth during pregnancy, infancy, childhood, and adolescence. Furthermore, we also review some mechanisms by which intestinal flora influence the host's linear growth. Although the data supports a link between intestinal flora and linear development in children, our review has limitations that prohibit us from fully verifying the causal relationship between gut flora and linear development in children. Improving the gut microbiota, in conjunction with renutrition techniques, has the potential to ameliorate the growth and development impairments currently associated with chronic illness and malnutrition in children.

Functional hypogonadism in adolescence: an overlooked cause of secondary hypogonadism

Hypogonadism is a clinical syndrome resulting from failure to produce physiological concentrations of sex steroid hormones with accompanying symptoms, such as slowed growth and delayed pubertal maturation. Hypogonadism may arise from gonadal disease (primary hypogonadism), dysfunction of the hypothalamic-pituitary axis (secondary hypogonadism) or functional hypogonadism. Disrupted puberty (delayed or absent) leading to hypogonadism can have a significant impact on both the physical and psychosocial well-being of adolescents with lasting effects. The diagnosis of hypogonadism in teenagers can be challenging as the most common cause of delayed puberty in both sexes is self-limited, also known as constitutional delay of growth and puberty (CDGP). Although an underlying congenital cause should always be considered in a teenager with hypogonadism, acquired conditions such as obesity, diabetes mellitus, other chronic diseases and medications have all been associated with low sex steroid hormone levels. In this review, we highlight some forms of functional hypogonadism in adolescents and the clinical challenges to differentiate normal variants from pathological states.

The benefits of physical therapy in juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in children and an important cause of short-term and long-term disability. Recommended physiotherapy activity programs are essential for controlling JIA associated complications such as stiffness, deformity, muscle contractures, and cramps. It is uncertain if physiotherapy (PT) can significantly enhance prognosis and quality of life (QOL). In this review we focused on the specific effects of various PT on JIA manifestations. To conduct a literature review, the databases PubMed, Scopus, and DOAJ (last access in June 2023) were searched. The PubMed search returned a total of 952 articles, Scopus returned 108, and DOAJ returned no results. After screening, the final list included 18 papers on PT treatment for JIA patients. In children with JIA, targeted PT exercise may have the ability to improve strength, posture, aerobic conditioning, gait, functional mobility, and reduce pain.

"Neuroimmunoendocrinology" in Children with Rheumatic Diseases: How Glucocorticoids Are the Orchestra Director

The neural, the endocrine, and the immune systems are studied as distinct districts in physiological and pathological settings. However, these systems must be investigated with an integrative approach, while also considering that therapeutic agents, such as glucocorticoids, can induce a reversible or irreversible change of this homeostasis. Children and adolescents affected by rheumatic diseases frequently need treatment with corticosteroids, and the treatment must sometimes be continued for a long time. In the biological era, the treat-to-target strategy allowed a real revolution in treatment, with significant steroid dose sparing or, in many patients, steroid treatment withdrawal. In this review, the impact of glucocorticoids on endocrine, immune, and neurologic targets is analyzed, and the crosstalk between these systems is highlighted. In this narrative review, we explore the reasoning as to why glucocorticoids can disrupt this homeostasis, we summarize some of the key results supporting the impact of glucocorticoids treatment on endocrine, immune, and neurologic systems, and we discuss the data reported in the international literature.

Disability and disease-related damage in Thai children and adolescents with juvenile idiopathic arthritis

BACKGROUND

Children and adolescents with juvenile idiopathic arthritis (JIA) may suffer from disability and disease-related damage. This study aimed to investigate the prevalence of disability and damage, and identify the factors associated with articular and extra-articular damage in children and adolescents with JIA in a resource-restricted setting in Thailand.

METHODS

This cross-sectional study enrolled JIA patients during June 2019-June 2021. Disability was assessed using the Child Health Assessment Questionnaire (CHAQ) and Steinbrocker classification criteria. Damage was evaluated using the Juvenile Arthritis Damage Index (JADI) and the modified-JADI (mJADI) tools.

RESULTS

There were 101 patients (50.5% female) with median age of 11.8 years. Median disease duration was 32.7 months. Enthesitis-related arthritis (ERA) was the most common subtype (33.7%), followed by systemic JIA (25.7%). Thirty-three (32.7%) patients had delayed diagnosis ≥ 6 months. Moderate to severe disability was found in 20 (19.8%) patients. Patients with Steinbrocker functional classification > class I were seen in 17.9%. Thirty-seven (36.6%) patients had articular damage. Extra-articular complications were observed in 24.8%. Growth failure and striae were the most common complications in 7.8%. Leg-length discrepancy was documented in 5.0%. Ocular damage was found in 1 patient with ERA. Multivariable logistic regression analysis revealed Steinbrocker functional classification > class I (aOR: 18.1, 95% CI: 3.9-84.6; p < 0.001), delayed diagnosis ≥ 6 months (aOR: 8.5, 95%CI: 2.7-27.0; p < 0.001), and ERA (aOR: 5.7, 95%CI: 1.8-18.3; p = 0.004) as independent predictors of articular damage. Systemic corticosteroids use was the independent predictor of extra-articular damage (aOR: 3.8, 95%CI: 1.3-11.1; p = 0.013).

CONCLUSIONS

Disability and disease-related damage was identified in one-fifth and one-third of JIA patients. Early detection and treatment are essential for preventing permanent damage.

Juvenile idiopathic arthritis-associated genetic loci exhibit spatially constrained gene regulatory effects across multiple tissues and immune cell types

Juvenile idiopathic arthritis (JIA) is an autoimmune, inflammatory joint disease with complex genetic etiology. Previous GWAS have found many genetic loci associated with JIA. However, the biological mechanism behind JIA remains unknown mainly because most risk loci are located in non-coding genetic regions. Interestingly, increasing evidence has found that regulatory elements in the non-coding regions can regulate the expression of distant target genes through spatial (physical) interactions. Here, we used information on the 3D genome organization (Hi-C data) to identify target genes that physically interact with SNPs within JIA risk loci. Subsequent analysis of these SNP-gene pairs using data from tissue and immune cell type-specific expression quantitative trait loci (eQTL) databases allowed the identification of risk loci that regulate the expression of their target genes. In total, we identified 59 JIA-risk loci that regulate the expression of 210 target genes across diverse tissues and immune cell types. Functional annotation of spatial eQTLs within JIA risk loci identified significant overlap with gene regulatory elements (i.e., enhancers and transcription factor binding sites). We found target genes involved in immune-related pathways such as antigen processing and presentation (e.g., ERAP2, HLA class I and II), the release of pro-inflammatory cytokines (e.g., LTBR, TYK2), proliferation and differentiation of specific immune cell types (e.g., AURKA in Th17 cells), and genes involved in physiological mechanisms related to pathological joint inflammation (e.g., LRG1 in arteries). Notably, many of the tissues where JIA-risk loci act as spatial eQTLs are not classically considered central to JIA pathology. Overall, our findings highlight the potential tissue and immune cell type-specific regulatory changes contributing to JIA pathogenesis. Future integration of our data with clinical studies can contribute to the development of improved JIA therapy.

Why and How Should We Assess the Cardiovascular Risk in Patients with Juvenile Idiopathic Arthritis? A Single-Centre Experience with Carotid Intima-Media Measurements

Background: Children diagnosed with juvenile idiopathic arthritis (JIA) are thought to be more likely to develop cardiovascular disease in adulthood. The factors modulating the cardiovascular risk, involving exposure to secondhand smoking, sedentary lifestyle and abnormal body mass index, might have had a stronger impact during the COVID-19 pandemic. The lack of reliable prognostic markers for a higher probability of cardiovascular events might be solved by carotid intima-media thickness (cIMT) measurement. The paramount goal of the study was to assess its usefulness in JIA patients. Materials and Methods: The results of cIMT measured by a single physician in 45 children diagnosed with JIA were compared to 37 age- and sex-matched healthy counterparts. The analysis also involved anthropometric parameters, laboratory tests, and a survey regarding lifestyle-related factors. Results: Four JIA patients appeared to have cIMT above the 94th percentile. A positive correlation between erythrocytes sedimentation rate (ESR) and right carotid artery percentiles was found. Passive smoking increased the cardiovascular risk regardless of JIA. Doubling the daily screen time during the pandemic led to a significant reduction in children’s physical activity. However, the number of enrolled subjects was not enough to make significant recommendations. Conclusions: cIMT measurements remain an interesting perspective for future cardiovascular screening of children with JIA. It has yet to be determined whether it should be considered in all JIA patients on a reliable basis.

Nutritional Aspects of Juvenile Idiopathic Arthritis: An A to Z for Dietitians

Juvenile idiopathic arthritis (JIA) represents a chronic, autoimmune, rheumatic musculoskeletal disease with a diagnosis before 16 years of age. Chronic arthritis is a common manifestation in all JIA subtypes. The nature of JIA, in combination to its therapy often results in the development of nutrition-, gastrointestinal (GI)- or metabolic-related issues. The most-common therapy-related nutritional issues involve methotrexate (MTX) and glucocorticosteroids (GCC) adverse events. MTX is a folic acid antagonist, thus supplementation with folic acid in required for improving GI side effects and correcting low serum levels. On the other hand, long-term GCC administration is often associated with hyperglycemia, insulin resistance and growth delay. This relationship is further aggravated when more joints are affected and greater doses of GCC are being administered. Apart from stature, body mass index z-scores are also suboptimal in JIA. Other signs of malnutrition include decreased phase angle and muscle mass, especially among patients with polyarthritis JIA. Evidence also points to the existence of an inverse relationship between disease activity and overweight/obesity. Specific dietary patterns, including the anti-inflammatory diet, might confer improvements in selected JIA outcomes, but the level of available research is yet insufficient to draw safe conclusions. The majority of patients exhibit suboptimal vitamin D status; hence, supplementation is recommended. Collectively, the evidence indicates that, due to the age of onset and the complexity of the disease, along with its pharmacotherapy, children with JIA are prone to the development of several nutritional problems, warranting expert monitoring. Vitamin deficiencies, oral and GI-problems limiting dietary intake, faltering growth, overweight and obesity, physical inactivity, or impaired bone health are among the many nutritional issues in JIA requiring dietitian support.

Bone health in childhood and adolescence: an overview on dual-energy X-ray absorptiometry scanning, fracture surveillance and bisphosphonate therapy for low-middle-income countries

Bone accrual in childhood determines bone health in later life. Loss of bone strength in early life can lead to increased morbidity and reduced quality of life in childhood and adolescence. Increased availability of assessment tools and bisphosphonate therapy, together with increased awareness on the significance of fracture history and risk factors, have led to greater opportunities, to improve detection and optimize management of children and adolescents with bone fragility globally, including those in lower resource settings. Bone mineral density z-scores and bone mineral content are surrogate measures of bone strength, which can be measured by dual-energy X-ray absorptiometry (DXA), in growing individuals. DXA can aid in the diagnosis and management of primary and secondary bone fragility disorders in childhood. DXA helps evaluate children with clinically significant fractures, and monitor those with bone fragility disorders, or at high risk for compromised bone strength. Obtaining DXA images can however be challenging, especially in younger children, due to difficulty in positioning and movement artefacts, while paediatric DXA interpretation can be confounded by effects of growth and puberty. Furthermore, access to DXA facilities as well as appropriate paediatric reference norms and expertise for interpretation, may not be easily available especially in lower resource settings. Pediatric bone experts are now placing increasing emphasis on the fracture phenotype and clinical context to diagnose osteoporosis over bone mineral density (BMD) by DXA. Low trauma vertebral fractures are now recognized as a hallmark of bone fragility, and spinal fracture surveillance by either conventional lateral thoracolumbar radiographs or vertebral fracture assessment by DXA is gaining increasing importance in diagnosing childhood osteoporosis, and initiating bone protective therapy. Furthermore, it is now understood that even a single, low-trauma long bone fracture can signal osteoporosis in those with risk factors for bone fragility. Intravenous bisphosphonate therapy is the mainstay of treatment for childhood bone fragility disorders. Other supportive measures to improve bone strength include optimizing nutrition, encouraging weight bearing physical activity within the limits of the underlying condition, and treating any associated endocrinopathies. With this paradigm shift in childhood osteoporosis evaluation and management, lack of DXA facilities to assess BMD at baseline and/or provide serial monitoring is not a major barrier for initiating IV bisphosphonate therapy in children in whom it is clinically indicated and would benefit from its use. DXA is useful, however, to monitor treatment response and optimal timing for treatment discontinuation in children with transient risk factors for osteoporosis. Overall, there is lack of awareness and paucity of guidelines on utilizing and adopting available resources to manage paediatric bone disorders optimally in lower-resource settings. We provide an evidence-based approach to the assessment and management of bone fragility disorders in children and adolescents, with appropriate considerations for lower resource settings including LMIC countries.

Tissue-resident memory T cells: The key frontier in local synovitis memory of rheumatoid arthritis

Rheumatoid arthritis (RA) is a highly disabling, systemic autoimmune disease. It presents a remarkable tendency to recur, which renders it almost impossible for patients to live without drugs. Under such circumstances, many patients have to suffer the pain of recurrent attacks as well as the side effects of long-term medication. Current therapies for RA are primarily systemic treatments without targeting the problem that RA is more likely to recur locally. Emerging studies suggest the existence of a mechanism mediating local memory during RA, which is closely related to the persistent residence of tissue-resident memory T cells (T_RM). T_RM, one of the memory T cell subsets, reside in tissues providing immediate immune protection but driving recurrent local inflammation on the other hand. The heterogeneity among synovial T_RM is unclear, with the dominated CD8⁺ T_RM observed in inflamed synovium of RA patients coming into focus. Besides local arthritis relapse, T_RM may also contribute to extra-articular organ involvement in RA due to their migration potential. Future integration of single-cell RNA sequencing (scRNA-seq) with spatial transcriptomics to explore the gene expression patterns of T_RM in both temporal dimension and spatial dimension may help us identify specific therapeutic targets. Targeting synovial T_RM to suppress local arthritis flares while using systemic therapies to prevent extra-articular organ involvement may provide a new perspective to address RA recurrence.

Quantitative proteomics analysis to assess protein expression levels in the ovaries of pubescent goats

Background

Changes in the abundance of ovarian proteins play a key role in the regulation of reproduction. However, to date, no studies have investigated such changes in pubescent goats. Herein we applied isobaric tags for relative and absolute quantitation (iTRAQ) and liquid chromatography–tandem mass spectrometry to analyze the expression levels of ovarian proteins in pre-pubertal (n = 3) and pubertal (n = 3) goats.

Results

Overall, 7,550 proteins were recognized; 301 (176 up- and 125 downregulated) were identified as differentially abundant proteins (DAPs). Five DAPs were randomly selected for expression level validation by Western blotting; the results of Western blotting and iTRAQ analysis were consistent. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis indicated that DAPs were enriched in olfactory transduction, glutathione metabolism, and calcium signaling pathways. Besides, gene ontology functional enrichment analysis revealed that several DAPs enriched in biological processes were associated with cellular process, biological regulation, metabolic process, and response to stimulus. Protein–protein interaction network showed that proteins interacting with CDK1, HSPA1A, and UCK2 were the most abundant.

Conclusions

We identified 301 DAPs, which were enriched in olfactory transduction, glutathione metabolism, and calcium signaling pathways, suggesting the involvement of these processes in the onset of puberty. Further studies are warranted to more comprehensively explore the function of the identified DAPs and aforementioned signaling pathways to gain novel, deeper insights into the mechanisms underlying the onset of puberty.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08699-y.

Bone Health in Children with Rheumatic Disorders: Focus on Molecular Mechanisms, Diagnosis, and Management

Bone is an extremely dynamic and adaptive tissue, whose metabolism and homeostasis is influenced by many different hormonal, mechanical, nutritional, immunological and pharmacological stimuli. Genetic factors significantly affect bone health, through their influence on bone cells function, cartilage quality, calcium and vitamin D homeostasis, sex hormone metabolism and pubertal timing. In addition, optimal nutrition and physical activity contribute to bone mass acquisition in the growing age. All these factors influence the attainment of peak bone mass, a critical determinant of bone health and fracture risk in adulthood. Secondary osteoporosis is an important issue of clinical care in children with acute and chronic diseases. Systemic autoimmune disorders, like juvenile idiopathic arthritis, can affect the skeletal system, causing reduced bone mineral density and high risk of fragility fractures during childhood. In these patients, multiple factors contribute to reduce bone strength, including systemic inflammation with elevated cytokines, reduced physical activity, malabsorption and nutritional deficiency, inadequate daily calcium and vitamin D intake, use of glucocorticoids, poor growth and pubertal delay. In juvenile arthritis, osteoporosis is more prominent at the femoral neck and radius compared to the lumbar spine. Nevertheless, vertebral fractures are an important, often asymptomatic manifestation, especially in glucocorticoid-treated patients. A standardized diagnostic approach to the musculoskeletal system, including prophylaxis, therapy and follow up, is therefore mandatory in at risk children. Here we discuss the molecular mechanisms involved in skeletal homeostasis and the influence of inflammation and chronic disease on bone metabolism.

Implications of Evolving Disease Classification for Drug Approval in Juvenile Idiopathic Arthritis

The classification of inflammatory arthritis incorporates a sharp divide between diseases of childhood onset, grouped together as juvenile idiopathic arthritis, and diseases such as rheumatoid arthritis that begin by definition in adulthood. An important consequence of this divide is that regulatory authorities and many rheumatologists regard pediatric and adult arthritides as truly different, with the implication that drugs should be evaluated separately for each category. However, it is now clear that most forms of arthritis transcend the pediatric/adult boundary and that agents generally exhibit comparable success irrespective of age of onset, offering new opportunities in drug development and regulation focused on pharmacology and safety rather than efficacy. This paradigm shift will enable advances in arthritis treatment, originating either with adults or children, to translate more rapidly across the age spectrum.

Vitamin D Supplementation in Patients with Juvenile Idiopathic Arthritis

Vitamin D has been implicated in the pathogenesis of skeletal disorders and various autoimmune disorders. Vitamin D can be consumed from the diet or synthesized in the skin upon ultraviolet exposure and hydroxylation in the liver and kidneys. In its bioactive form, vitamin D exerts a potent immunomodulatory effect and is important for bone health. Juvenile idiopathic arthritis (JIA) is a collection of inflammatory joint diseases in children that share the manifestation of inflamed synovium, which can result in growth arrest, articular deformity, bone density loss, and disability. To evaluate the potential effect of vitamin D on JIA disease manifestations and outcomes, we review the role of vitamin D in bone metabolism, discuss the mechanism of vitamin D in modulating the innate and adaptive immune systems, evaluate the clinical significance of vitamin D in patients with JIA, and summarize the supplementation studies.

Spectrum of Clinical Research in Juvenile Idiopathic Arthritis: A Cross-Sectional Analysis of Registered Studies in Clinicaltrials.gov and Clinicaltrialsregister.eu

The management of juvenile idiopathic arthritis (JIA) has improved tremendously in recent years due to the introduction of new drug therapies but remains complex in terms of non-pharmaceutical issues. In order to determine the direction of scientific progress by characterizing the current spectrum of ongoing clinical research in JIA, we analyzed all ongoing studies in the field of JIA—registered in clinicaltrials.gov and clinicaltrialsregister.eu—concerning sponsoring, enrollment, duration, localization, and particularly objectives. The close of the database was 7 January 2021. After identifying double-registered studies, n = 72 went into further analysis. Of these, 61.1% were academia-sponsored and 37.5% were sponsored by the pharma industry. The majority of the studies was of the interventional type (77.8%), while others (22.2%) were observational. The median planned enrollments were 100 participants (interventional studies) and 175 participants (observational studies), respectively. The duration differed remarkably from one month to more than 15 years, with a median of 42.5 months. A total of 61.1% of studies were located in a single country, and 38.9% were in several. Europe and North America clearly dominated the study localizations. The study objectives were DMARDs (56.9%), followed by diagnostics and disease activity measurement (18.1%), and medication other than DMARD (12.5%), besides others. Studies on DMARDs were mainly sponsored by industry, predominantly interventional studies on established and novel biologics, with several on specific issues such as systemic JIA and others. The spectrum of registered studies is currently centered on drug therapy and diagnostics, while other issues in JIA play a subordinated role in current research. Drug development was transferred from adult rheumatology into the JIA population with little innovation for children. Future research should take specific pediatric needs better into account.

Early Sexual Health and Reproductive Implications in Pediatric Rheumatic Diseases

A comprehensive review of reproductive health subtopics, including puberty, menarche, sexual orientation, gender identity, and gynecologic cancers as they pertain to patients with pediatric rheumatic diseases and those who care for them. Rheumatic disease medications and their effect on reproductive health across childhood and adolescence are also reviewed.