Long-COVID are often accompanied by the development of autoimmun disorders. Such dysregulation of the immune system can be caused by reactivation of "sluggish" herpesvirus infection in patients after COVID-19. The one of the possible causes of autoimmunization is a change in the cytotoxic functions of NK cells under the influence of HHV6. The aim of research was to study the expression of receptor-ligand Fas-FasL, regulating marker CD38 and inhibitory receptor TIM-3 on NK cells in patients with long-COVID after mild, moderate, and severe stage of COVID-19 in the anamnesis with or without reactivation of HHV-6 and to identify risk factors for the formation of autoimmune disorders in these patients. This study investigated 124 adults (73 female and 51 male) aged 18 to 65 years with long-COVID. The groups of patients with long-COVID were divided depending on mild, moderate, and severe forms of COVID-19 in the anamnesis and with/without reactivation of HHV-6. The control group included 20 healthy participants. Molecular genetic studies (PCR) were performed for all patients to detect the existence of DNA HHV6. Multiparametric flow cytometry was performed on 124 EDTA peripheral blood samples collected from long-COVID patients and 20 healthy controls. There was defined an imbalance between acute antiviral mechanisms, the response contributing to tissue damage and immunopathology, probably autoimmunity in patients with long-COVID after different forms of COVID-19 with reactivation of HHV-6. The presence of HHV-6 in groups with long-COVID was accompanied by higher expression of FasL and CD38, especially in patients, who had a severe form of COVID-19 in the anamnesis. The decrease in TIM-3 in patients with reactivation of HHV-6 compared to patients without HHV-6 puts the preservation of immunological tolerance at risk of Th1-dependent immune responses. The reactivation of HHV-6 is accompanied by higher expression of FasL and CD38, which indicates increased hyperactivation of NK cells, their cytotoxic activity, and subsequent exhaustion. NK cells of these patients lose their immunoregulatory ability, this creates prerequisites for the development of immunopathology, probably autoimmune processes.

Keywords: Autoimmune disease; Exhaustion of cells; Human herpesvirus 6; Long-COVID; NK cells.

УДК: 616.8-053.2:613.2+618.3
Поширеність харчової алергії (ХА) стрімко зростає, особливо серед дітей раннього віку. Введення прикорму є критичним періодом у формуванні імунної толерантності до харчових алергенів. Метод Baby-led weaning (BLW), що передбачає самостійне вживання їжі немовлятами, потенційно може змінювати профіль сенсибілізації до алергенів. Вплив BLW на розвиток ХА залишається недостатньо вивченим.
Мета роботи – порівняти рівень сенсибілізації до харчових алергенів серед дітей, які отримували прикорм за методикою BLW і традиційним способом, з урахуванням наявності атопічного дерматиту (АД).
Матеріали і методи. Досліджено 120 дітей, розподілених на чотири групи залежно від типу прикорму (BLW або традиційний) та наявності АД. Рівень сенсибілізації до харчових алергенів оцінювали за допомогою панелі «Харчова-4» (22 алергени) методом імуноферментного аналізу (ІФА).
Результати та їх обговорення. Найвищі рівні сенсибілізації до харчових алергенів виявлено у дітей з АД незалежно від типу прикорму (p = 0,301). Водночас серед дітей без АД немовлята на BLW прикормі мали вищий рівень сенсибілізації до харчових алергенів порівняно з групою традиційного прикорму (p = 0,015). Сенсибілізація до білків коровʼячого молока частіше зустрічалася у дітей з АД на BLW прикормі, ніж у немовлят із традиційним прикормом. Також у дітей, які отримували BLW, частіше виявляли сенсибілізацію до додаткових харчових алергенів. Окрім цього, рівень загального IgE у дітей без АД, які отримували BLW прикорм, був вищим, ніж у дітей на традиційному прикормі (p = 0,029).
Висновки Немовлята на BLW прикормі, незалежно від наявності АД, демонструють підвищену схильність до сенсибілізації харчовими алергенами порівняно з традиційним прикормом. Це вказує на необхідність подальших досліджень щодо безпечності BLW у контексті розвитку ХА
Background. The prevalence of food allergy (FA) is rapidly increasing, particularly among young children. The introduction of complementary feeding is a critical period for the development of immune tolerance to food allergens. Baby-led weaning (BLW), a feeding method that allows infants to self-feed, may potentially alter the sensiti-zation profile to allergens. However, the impact of BLW on FA development remains insufficiently studied.
Purpose – to compare the level of sensitization to food allergens among children introduced to complementary feeding using the BLW method versus the traditional approach, considering the presence of atopic dermatitis (AD).
Materials and Methods A total of 120 children were examined and divided into four groups based on the type of complementary feeding (BLW or traditional) and the presence of AD. Sensitization to food allergens was assessed using the «Food-4» panel (22 allergens) by enzyme-linked immunosorbent assay (ELISA).
Results The highest levels of sensitization to food allergens were observed in child- ren with AD, regardless of the feeding method (p = 0.301). However, among childrenи without AD, infants following the BLW method had a significantly higher level of sensitization to food allergens compared to those receiving traditional complementary feeding (p = 0.015). Sensitization to cowʼs milk proteins was more frequently detected in BLW-fed infants with AD compared to children with AD on traditional complementary feeding. Additionally, BLW-fed infants showed sensitization to a wider range of food allergens. Furthermore, among children without AD, those following the BLW method had higher total IgE levels than those on traditional complementary
feeding (p = 0.029).
Conclusions  Infants introduced to complementary feeding via the BLW method, regardless of the presence of AD, exhibit a higher tendency toward food allergen sensitization compared to those following traditional feeding. These findings highlight the need for further research on the safety of BLW in the context of FA developmen

Зростання поширеності алергічних захворювань робить питання раннього надходження харчових алергенів до організму немовлят актуальним. Доведено, що діти з атопічним дерматитом (АД) більш схильні до розвитку харчової алергії (ХА), тоді як алергени можуть провокувати загострення АД. Один із сучасних підходів до підгодовування немовлят (введення в раціон дитини твердої їжі) є метод baby-led weaning (BLW), що передбачає самостійне керування дитини процесом споживання їжі.
Мета роботи – оцінити рівень сенсибілізації дітей грудного віку з/без АД до різних алергенів залежно від виду підгодовування (прикорму).
Матеріали і методи. Обстежено 120 дітей, розподілених на чотири групи за видом підгодовування (BLW або традиційне) та наявністю АД. Сенсибілізацію визначали за допомогою ALEX2®-MADX (MedTech, Vienna).
Результати. Найвищий рівень гіперчутливості виявили у дітей з АД, яким вводили у раціон тверді продукти за методом BLW, найнижчий – у немовлят без АД на традиційному (класичному) підгодовуванні (р=0.025). У групах без АД (метод BLW і традиційне підгодовування) частота гіперчутливості була однакова (50.0%). Сенсибілізація була найвищою у дітей з АД, яким вводили тверду їжу за методом BLW- (p=0.005). Навіть у групі без АД на BLW-підгодовуванні (23.3%) вона була значно вища, ніж у немовлят на традиційному підгодовуванню (6.67%, p=0.041). Найчастіше
сенсибілізація простежувалася до білків коров’ячого молока (p=0.043) та білка курячого яйця (p=0.048).
Висновки. Виявлено взаємозв’язок між введенням твердої їжі за методом BLW і вищими рівнями сенсибілізації, особливо у дітей із АД. Немовлятам на BLWпідгодовуванні і у яких простежується сенсибілізація до харчових алергенів рекомендоване контрольоване введення продуктів та додаткове тестування на специфічні IgE для профілактики тяжких алергічних реакцій.
Ключові слова: Baby-led weaning, види підгодовування (прикорм), атопічний дерматит, харчова алергія.

Pain in both peripheral and axial joints is a major symptom in patients with psoriaticarthritis (PsA) and axial spondyloarthritis (axSpA). Emerging evidence demonstrates pain mechanisms,beyond those related to inflammation or joint damage, based on aberrant processing of nociceptivestimuli peripherally as well as centrally. The Janus kinase/signal transducers and activators of transcrip-tion (JAK-STAT) signaling pathway has been implicated in the processing of pain beyond its role inmediating inflammation and inhibitors of this pathway approved for the treatment of axSpA and PsAhave been shown to alleviate a broad array of pain outcomes in both axial and peripheral joints.Areas covered: We review recent definitions and standardization of the nomenclature for categorizingchronic pain according to causality, assessment tools to evaluate nociplastic pain, the pathophysiologic roleof JAK-STAT signaling in nociplastic pain, evidence for the presence of nociplastic pain in axSpA and PsA,and the impact of JAK inhibitors (JAKi) on pain outcomes in clinical trials (PubMed: 01/01/2019-04/01-2024).Expert opinion: Nociplastic pain assessment has been confined almost entirely to the use of a limitednumber of questionnaires in cross-sectional studies of these diseases. Though effective for alleviatingpain, it is unclear if JAKi specifically impact nociplastic pain.ARTICLE HISTORYReceived 20 May 2024Accepted 30 August 2024KEYWORDSAnkylosing spondylitis; axialspondyloarthritis; nociplasticpain; janus kinases; psoriaticarthritis1. IntroductionPain is a key symptom of the inflammatory arthritis that may affectaxial and peripheral joints in patients with axSpA and PsA. Recentavailability of bDMARD and targeted synthetic DMARD (tsDMARD)agents targeting cytokines implicated in inflammation has led toa significantly beneficial impact on pain as well as other symptomsrelated to joint inflammation. However, remission of pain aftersuch treatment occurs in only 20–25% of patients, irrespective ofthe DMARD that is used. Moreover, evaluation of the severity ofand changes in inflammation using objective measures of inflam-mation, such as serum C-reactive protein (CRP) and magneticresonance imaging (MRI) parameters of joint inflammation, hasdemonstrated only limited correlation with assessments of painseverity and change with treatment, this being limited to patientswith short symptom duration and dissipating over time.Conversely, recent work in axSpA has demonstrated beneficialeffects of a specific bDMARD on pain in the apparent absence ofany objective features of inflammation [1].The recent introduction of JAKi for the treatment of PsA andaxSpA has further put the spotlight on our understanding ofmechanisms accounting for pain in these conditions because ofobservations demonstrating a rapid onset of significant pain reliefin clinical trials [2,3]. This has coincided with recent studies inanimal models suggesting a role for JAK-STAT signaling, andcytokines modulated by JAK signaling pathways, in peripheraland central processing of afferent pain signals [4,5]. There is alsoincreasing awareness that abnormalities of central and peripheralpain processing pathways, unrelated to abnormalities of neural ornon-neural tissues such as joints, may be important contributorsto the perception of pain in patients with axSpA and PsA.This manuscript aims to review the recent literature thatfocuses on a consensus-based mechanistic framework fordefining different categories of pain, outcome tools for theassessment of these different categories of pain, evidence forthe presence of pain in axSpA and PsA that may be unrelatedto inflammation or joint damage, the evidence supportinga role for JAK-STAT signaling in non-inflammatory pain, andwhat is known from clinical trials about the impact of treat-ment with JAKi on pain that may be unrelated to anti-inflammatory effects. The review will focus particularly onnociplastic pain, which is an emerging area of considerableinterest to clinicians because of its prevalence in patients withaxSpA and PsA, and the possibility that JAKi could havediverse mechanistic effects in ameliorating pain.2. Nomenclature of chronic pain and relevantoutcome tools2.1. Pain definitions and the international associationfor the study of pain frameworkIn 2020, the International Association for the Study of Pain(IASP) updated the general definition of pain for the first timeCONTACT Walter P. Maksymowych walter.maksymowych@ualberta.ca Department of Medicine, University of Alberta, 568 Heritage Medical ResearchBuilding, Edmonton, Alberta T6R 2G8, CanadaEXPERT REVIEW OF CLINICAL IMMUNOLOGY2025, VOL. 21, NO. 2, 137–152https://doi.org/10.1080/1744666X.2024.2400294© 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by-nc-nd/4.0/),which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way.The terms on which this article has been published allow the posting of the Accepted Manuscript in a repository by the author(s) or with their consent.

This update addresses new developments in imaging of axial spondyloarthritis from the past 5 years. These have focused mostly on enhanced CT and MRI-based technologies that bring greater precision to the assessment of both inflammatory and structural lesions in the sacroiliac joint. An international consensus has recommended a 4-sequence MRI for routine diagnostic evaluation of the sacroiliac joint aimed at depicting the location and extent of inflammation as well as an erosion-sensitive sequence for structural damage. The latter include high resolution thin slice sequences that accentuate the interface between subchondral bone and the overlying cartilage and joint space as well as synthetic CT, a deep learning-based technique that transforms certain MRI sequences into images resembling CT. Algorithms based on deep learning derived from plain radiographic, CT, and MRI datasets are increasingly more accurate at identifying sacroiliitis and individual lesions observed on images of the sacroiliac joints and spine.

Keywords: Axial spondyloarthritis; Computed tomography; Deep learning; Diagnosis; Magnetic resonance imaging; Prognosis; Sacroiliac joint; Spine.