Polyneuropathy in systemic sclerosis: exploring the causes and biomarkers.

Introduction: Systemic sclerosis (SSc) is a rare autoimmune disease with multiple organ involvement; however, the contribution of the nervous system (NS) remains relatively understudied. There are no specific data on the role of the autoimmune response and inflammation in the development of peripheral nerve system (PNS) damage in SSc and markers to assess this damage have yet to be identified. Objectives: The primary objective of this study was to define the autoimmune mechanisms that lead to neuropathy by identifying antibodies (Abs) that target certain component of the NS or are associated with SSc. The secondary objective was to identify markers of NS damage that correlate with the detection and progression of polyneuropathy (PNP). Methods: This study included patients diagnosed with SSc who met ACR/EULAR 2013 classification criteria at two leading Latvian hospitals between January 2016 and December 2021. Patients underwent a nerve conduction study (NCS). The SSc-associated Abs, Abs against myelin-associated glycoprotein (MAG) and anti-ganglioside Abs (GM1, GM2, GD1a, GD1b and GQ1b) were analysed. Potential serum PNS biomarkers-neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), fibroblast growth factor 21 (FGF21) and growth/differentiation factor 15 (GDF15)-were measured. Results: We recruited 103 Caucasian patients diagnosed with SSc. SSc-associated Abs did not differ significantly between patients with and without PNP (p > 0.05). Anti-MAG and anti-ganglioside Abs in patients with PNP did not present a significant increase above the reference range. NfL, GFAP and GDF15 were significantly elevated in the presence of PNP (p < 0.05), with a moderate to high effect size (r = 0.36-0.65). Our regression analysis revealed a strong association between the HAQ-DI score, older age, male gender and the risk of developing PNP. Conclusion: The development of PNP in patients with SSc is most likely due to ageing, natural progression and the sequelae of the disease. Several serum biomarkers-NfL, GFAP and GDF15-could be used as relevant diagnostic biomarkers for PNP in patients with SSc. Future studies are warranted to validate the diagnostic efficacy of these biomarkers and to unravel the complex interplay of factors leading to PNP in patients with SSc.

Epidemiological and clinical characteristics of adult patients with chronic spontaneous urticaria in Latvia: insights from a two-centre study.

Chronic spontaneous urticaria (CSU) significantly impacts the quality of life of affected individuals. This study aimed to elucidate the epidemiological and clinical profiles of adult CSU patients in Latvia. Patient interviews and electronic medical records from two study centres in Riga, Latvia, were reviewed. PROMs, including UCT, UAS7, USS, and CU-Q2oL, were used to assess disease control, activity, severity, and quality of life. Statistical analysis was performed using Jamovi v. 2.3.28 and IBM SPSS v. 29.0.0.0. The cohort included 140 CSU patients (76.4% female; mean age 41.3 ± 14.9 years), mostly urban residents (87.1%) and non-smokers (53.6%). Urticaria with angioedema occurred in 52.1% and isolated urticaria in 47.9%, with 40% experiencing CSU for 1-5 years. Accompanying symptoms were reported by 63% and triggers by 72.9%. Allergy history and autoimmune disease diagnosis were noted in 49.3% and 29.3%. Treatment mainly involved second-generation antihistamines (85.7%) and omalizumab (17.9%). Mean scores for USS, UCT, and UAS7 were 28.8 (SD: 17.8), 8.2 (SD: 3.7), and 17.2 (SD: 14.1). UAS7 indicated severe CSU in 28.6%, and UCT suggested poorly controlled disease in 77.9%. CU-Q2oL total scores revealed mental status as the most affected domain (mean score: 51.7, SD: 28.7), with a significant association between accompanying symptoms and questionnaire scores. This study provides insights into the demographic and clinical aspects of CSU patients in Latvia, highlighting areas for potential improvement in patient care and emphasizing the need for further investigation into treatment outcomes and patient quality of life.

Exploring disease-specific metabolite signatures in hereditary angioedema patients.

Introduction: Hereditary angioedema (HAE) is a rare, life-threatening autosomal dominant genetic disorder caused by a deficient and/or dysfunctional C1 esterase inhibitor (C1-INH) (type 1 and type 2) leading to recurrent episodes of edema. This study aims to explore HAE patients' metabolomic profiles and identify novel potential diagnostic biomarkers for HAE. The study also examined distinguishing HAE from idiopathic angioedema (AE). Methods: Blood plasma samples from 10 HAE (types 1/2) patients, 15 patients with idiopathic AE, and 20 healthy controls were collected in Latvia and analyzed using LC-MS based targeted metabolomics workflow. T-test and fold change calculation were used to identify metabolites with significant differences between diseases and control groups. ROC analysis was performed to evaluate metabolite based classification model. Results: A total of 33 metabolites were detected and quantified. The results showed that isovalerylcarnitine, cystine, and hydroxyproline were the most significantly altered metabolites between the disease and control groups. Aspartic acid was identified as a significant metabolite that could differentiate between HAE and idiopathic AE. The mathematical combination of metabolites (hydroxyproline * cystine)/(creatinine * isovalerylcarnitine) was identified as the diagnosis signature for HAE. Furthermore, glycine/asparagine ratio could differentiate between HAE and idiopathic AE. Conclusion: Our study identified isovalerylcarnitine, cystine, and hydroxyproline as potential biomarkers for HAE diagnosis. Identifying new biomarkers may offer enhanced prospects for accurate, timely, and economical diagnosis of HAE, as well as tailored treatment selection for optimal patient care.

Hereditary or acquired? Comprehensive genetic testing assists in stratifying angioedema patients.

Hereditary angioedema (HAE) poses diagnostic challenges due to its episodic, non-specific symptoms and overlapping conditions. This study focuses on the genetic basis of HAE, particularly focusing on unresolved cases and those with normal C1-inhibitor levels (nC1-INH HAE). This study reveals that conventional testing identified pathogenic variants in only 10 patients (n = 32), emphasizing the necessity for an integrative approach using genome, exome, and transcriptome sequencing. Despite extensive genetic analyses, the diagnostic yield for nC1-INH HAE remains low in our study, the pathogenic variant for nC1-INH HAE was identified in only 1 patient (n = 21). Investigation into candidate genes yielded no pathogenic variants, prompting a re-evaluation of patients' diagnoses. This study advocates for a nuanced approach to genetic testing, recognizing its limitations and emphasizing the need for continuous clinical assessment. The complex genetic landscape of nC1-INH HAE necessitates further research for a more comprehensive understanding. In conclusion, this study contributes valuable insights into the genetic intricacies of HAE, highlighting the challenges in diagnosis and the evolving nature of the disease. The findings underscore the importance of advanced sequencing techniques and an integrated diagnostic strategy in unravelling the complexities of HAE, particularly in nС1-INH HAE cases.

CRUSE® -An innovative mobile application for patient monitoring and management in chronic spontaneous urticaria.

BACKGROUND: Chronic spontaneous urticaria (CSU) is unpredictable and can severely impair patients' quality of life. Patients with CSU need a convenient, user-friendly platform to complete patient-reported outcome measures (PROMs) on their mobile devices. CRUSE® , the Chronic Urticaria Self Evaluation app, aims to address this unmet need. METHODS: CRUSE® was developed by an international steering committee of urticaria specialists. Priorities for the app based on recent findings in CSU were defined to allow patients to track and record their symptoms and medication use over time and send photographs. The CRUSE® app collects patient data such as age, sex, disease onset, triggers, medication, and CSU characteristics that can be sent securely to physicians, providing real-time insights. Additionally, CRUSE® contains PROMs to assess disease activity and control, which are individualised to patient profiles and clinical manifestations. RESULTS: CRUSE® was launched in Germany in March 2022 and is now available for free in 17 countries. It is adapted to the local language and displays a country-specific list of available urticaria medications. English and Ukrainian versions are available worldwide. From July 2022 to June 2023, 25,710 observations were documented by 2540 users; 72.7% were females, with a mean age of 39.6 years. At baseline, 93.7% and 51.3% of users had wheals and angioedema, respectively. Second-generation antihistamines were used in 74.0% of days. CONCLUSIONS: The initial data from CRUSE® show the wide use and utility of effectively tracking patients' disease activity and control, paving the way for personalised CSU management.

COVID-19 Vaccination Coverage and Factors Influencing Vaccine Hesitancy among Patients with Inborn Errors of Immunity in Latvia: A Mixed-Methods Study.

BACKGROUND: The European Society for Immunodeficiencies recommends that all patients with inborn errors of immunity (IEI) without contraindications should receive SARS-CoV-2 vaccination. The aim of this study was to investigate the reasons that discourage IEI patients from receiving the recommended vaccination and to assess vaccination coverage among IEI patients in Latvia. METHODS: In this multicenter mixed-methods study, the vaccination status of all patients with IEI within two tertiary centers in Latvia was reviewed using electronic health records. Semi-structured interviews were conducted with 16 IEI patients who did not undergo vaccination, and a thematic analysis was performed. RESULTS: A total of 341 patients (49.3% female; median age 19.7 years (IQR:17)) were included in the quantitative part. The proportion of fully vaccinated individuals aged ≥ 12 years was 66.8%-70.9% with patients with selective IgA deficiency and 58.8% with other IEI (χ² = 14.12, p < 0.001). The proportion of fully vaccinated individuals aged 5-11 years was 11.1%. Age was associated with vaccination status: younger patients were found to have a significantly lower likelihood of receiving vaccination (U = 8585, p < 0.001). The five main themes identified were as follows: (1) fear and uncertainty; (2) risk and benefit assessment: COVID-19 vaccine-is it worth it? (3) external influences: the dark horse of the decision-making-people around us; (4) individuals against the system; and (5) beliefs about vaccination and COVID-19. Under-representation of certain IEI groups and recall bias are possible limitations of this study. CONCLUSIONS: While most reasons for hesitancy were similar to those previously described in the general population, disease-specific concerns were also identified.

Cytokine Response Following SARS-CoV-2 Antigen Stimulation in Patients with Predominantly Antibody Deficiencies.

Predominantly antibody deficiencies (PADs) are inborn disorders characterized by immune dysregulation and increased susceptibility to infections. Response to vaccination, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), may be impaired in these patients, and studies on responsiveness correlates, including cytokine signatures to antigen stimulation, are sparse. In this study, we aimed to describe the spike-specific cytokine response following whole-blood stimulation with SARS-CoV-2 spike peptides in patients with PAD (n = 16 with common variable immunodeficiency and n = 15 with selective IgA deficiency) and its relationship with the occurrence of coronavirus disease 2019 (COVID-19) during up to 10-month follow-up period. Spike-induced antibody and cytokine production was measured using ELISA (anti-spike IgG, IFN-γ) and xMAP technology (interleukin-1ß (IL-1ß), IL-4, IL-6, IL-10, IL-15, IL-17A, IL-21, TNF-α, TGF-ß1). No difference was found in the production of cytokines between patients with PAD and controls. Anti-spike IgG and cytokine levels did not predict contraction of COVID-19. The only cytokine that distinguished between vaccinated and naturally infected unvaccinated PAD patients was IFN-γ (median 0.64 (IQR = 1.08) in vaccinated vs. 0.10 (IQR = 0.28) in unvaccinated). This study describes the spike-specific cytokine response to SARS-CoV-2 antigens, which is not predictive of contracting COVID-19 during the follow-up.

Clinical Symptoms Influencing Parkinson's Patients' Quality of Life in Latvia: A Single-Center Cohort Study.

Background and Objectives: Parkinson's disease (PD) is a chronic, progressive illness with a profound impact on health-related quality of life, and it is crucial to know what factors influence the quality of life throughout the course of the disease. This study aimed to evaluate PD patients' motor and non-motor symptoms to compare symptom severity between PD clinical phenotypes and to assess the impact of disease symptoms on quality of life in a cohort of Latvian patients. Materials and Methods: We evaluated 43 patients with Parkinson's disease. Fourteen patients had tremor dominant (TD) PD, twenty-five patients had postural instability/gait difficulty (PIGD), and four patients had a mixed phenotype. Results: The patients' mean age was 65.21 years, and the disease's mean duration was 7 years. The most common non-motor symptoms were fatigue (95.3%), sleep disturbance (83.7%), daytime sleepiness (83.7%), and pain and other sensations (81.4%). PIGD patients had a higher prevalence of depressed mood, daytime sleepiness, constipation, lightheadedness on standing, cognitive impairment, and severe gastrointestinal and urinary disturbances (as assessed using the SCOPA-AUT domains) compared with TD patients. A high prevalence of fatigue was assessed in both disease subtypes. Health-related quality of life significantly statistically correlated with MDS-UPDRS parts III and IV (r = 0.704), the Hoehn and Yahr scale (r = 0.723), as well as the SCOPA-AUT scale's gastrointestinal (r = 0.639), cardiovascular (r = 0.586), thermoregulatory (r = 0.566) and pupillomotor domains (r = 0.597). Conclusions: The severity of motor symptoms, as well as non-motor symptoms, such as fatigue, apathy, sleep problems and daytime sleepiness, pain, and disturbances in gastrointestinal and cardiovascular function, negatively affect PD patients' health-related quality of life. Thermoregulatory and pupillomotor symptoms also significantly affect PD patients' well-being.

Plasma neurofilament light chain level is not a biomarker of Charcot-Marie-Tooth disease progression: Results of 3-year follow-up study.

BACKGROUND AND PURPOSE: Charcot-Marie-Tooth disease (CMT) is a hereditary, slowly progressive neuropathy. Currently, there are no effective pharmacological treatments or sensitive disease activity biomarkers available. The aim of this study was to demonstrate the change in plasma neurofilament light chain (NfL) over time in a CMT cohort and analyse the association between CMT severity and NfL level. METHODS: Initially, 101 CMT patients and 64 controls were enrolled in the study. Repeated evaluation was performed in 73 patients and 28 controls at a 3-year interval. Disease severity assessment included clinical evaluation with CMT Neuropathy Score version 2 (CMTNSv2). Plasma NfL concentration was measured using the Simoa (single molecule array) NfL assay. RESULTS: Plasma NfL concentration was increased in the CMT group compared with controls (p < 0.001). Overall NfL level increased over the 3-year interval in both CMT (p = 0.012) and control (p = 0.001) groups. However, in 22 of 73 CMT patients and seven of 28 controls, the NfL level decreased from the baseline. Analysing the association between 3-year change in plasma NfL and disease severity (CMTNSv2), there was no correlation in the CMT group (r = 0.228, p = 0.052) or different CMT subgroups. CONCLUSIONS: Our study verifies increased plasma NfL concentrations in patients with CMT compared with controls. Longitudinal 3-year data showed a variable change in NfL levels between CMT subtypes. There was no association between change in NfL over time and disease severity. These findings suggests that NfL is not a biomarker for CMT progression.

National survey on clinical and genetic characteristics of patients with hereditary angioedema in Latvia.

BACKGROUND: Hereditary angioedema (HAE) is a rare and life-threatening inborn error of immunity. HAE is mostly caused by pathogenic variations in the serine protease inhibitor gene 1 (SERPING1), leading to deficient or dysfunctional C1-inhibitor (C1-INH), overproduction of bradykinin, and development of recurrent subcutaneous and/or submucosal oedema. The prevalence of HAE is 1 in 50,000 - 100000 people worldwide. We aimed to describe the clinical features and genetic spectrum of hereditary angioedema with C1-INH deficiency (C1-INH-HAE) in Latvia. METHODS: All patients from Latvia diagnosed with HAE (types I/II) from 2006 to March 2022 were included in the study. Laboratory tests and clinical data were analysed, and genetic tests with Sanger sequencing and whole genome sequencing were performed. RESULTS: The study identified 10 C1-INH-HAE patients (nine females, one male) from eight families. The point prevalence of HAE in Latvia is 0.53 per 100 000 inhabitants. Of all patients, seven (70%) had HAE type I and three (30%) had HAE type II. The median age of patients was 54 years and the median age at onset of symptoms was 15 years. A significant delay (median 20.5 years) until diagnosis was observed, and 60% of patients had a positive family history of angioedema. All HAE patients have been hospitalised a median two times during their lifetime. Skin (100%), abdominal (80%), and airway (80%) oedema were the most frequent symptoms. Triggering factors (60%) and prodromal symptoms (90%) were referred. Attacks were severe in 50% of patients, moderate in 10%, and mild in 40%. Pathogenic variations of SERPING1 were identified in eight patients (six families), confirming the diagnosis molecularly. In two patients (two families), no pathogenic variations in the genes were found even after whole genome sequencing. CONCLUSIONS: Current data shows a significant delay and clear underdiagnosis of HAE in Latvia. Higher awareness and better information and communication between doctors would improve the diagnosis and management of HAE; as would screening of family members, patients with recurrent angioedema unresponsive to antihistamines and glucocorticoids, and patients with recurrent episodes of severe, unexplained abdominal pain.

Clinical and genetic characterization of Netherton syndrome due to SPINK5 founder variant in Latvian population.

OBJECTIVE: Netherton syndrome (NS) (OMIM:256500) is a very rare autosomal recessive multisystem disorder mostly affecting ectodermal derivatives (skin and hair) and immune system. It is caused by biallelic loss-of-function variants in the SPINK5 gene, encoding the protease inhibitor lymphoepithelial Kazal-type-related inhibitor (LEKTI). MATERIAL, METHODS AND RESULTS: Here, we describe NS clinical and genetic features of homogenous patient group: 9 individuals from 7 families with similar ethnic background and who have the same SPINK5 variant (NM_006846.4: c.1048C > T, p.(Arg350*)) in homozygous or compound heterozygous states, suggesting that it is a common founder variant in Latvian population. Indeed, we were able to show that the variant is common in general Latvian population, and it shares the same haplotype among the NS individual. It is estimated that the variant arose >1000 years ago. Clinically, all nine patients exhibited typical NS skin changes (scaly erythroderma, ichthyosis linearis circumflexa, itchy skin), except for one patient who has a different skin manifestation-epidermodysplasia. Additionally, we show that developmental delay, previously underrecognized in NS, is a common feature among these patients. CONCLUSIONS: This study shows that the phenotype of NS individuals with the same genotype is highly homogeneous.

Prevalence of polyneuropathies among systemic sclerosis patients and impact on health-related quality of life.

INTRODUCTION: Systemic sclerosis (SSc) is a chronic rheumatic disease that affects multiple organ systems, including the peripheral nervous system. However, studies into the involvement of polyneuropathies (PNP) have shown inconsistent results. The aim of this study was to determine the prevalence of small (SFN) and large (LFN) fibre neuropathy among SSc patients and the impact on health-related quality of life (HRQoL). MATERIAL AND METHODS: The study enrolled 67 patients with diagnosed SSc. The severity of neuropathic symptoms was evaluated using shortened and revised total neuropathy scoring criteria. Nerve conduction studies were used for LFN, and quantitative sensory testing was used to evaluate SFN. Neuropathic pain was evaluated using a Douleur Neuropathique en 4 questionnaire, and the severity of anxiety symptoms was assessed using a Generalised Anxiety Disorder-7 scale. The Health Assessment Questionnaire-Disability Index was used to assess HRQoL. Previous data on antinuclear autoantibodies (ANA) test results was obtained. Statistical analysis was performed using SPSS software. RESULTS: LFN was diagnosed in 47.8% (n = 32/67) and SFN in 40.3% (n = 27/67) of the subjects. ANA positivity was not associated with the presence of LFN/SFN. The severity of neuropathic pain had a significant correlation with anxiety symptoms (r = 0.61, p < 0.001), the severity of neuropathy symptoms (r = 0.51, p < 0.001) and HRQoL (r = 0.45, p < 0.001). The severity of neuropathy symptoms correlated with HRQoL (r = 0.39, p = 0.001). CONCLUSIONS: We demonstrated that PNP are found in almost all SSc patients. Also, SFN is as common as LFN. Additionally, we found that the severity of neuropathy symptoms and neuropathic pain are both associated with a worse HRQoL.

Long-Term Immunological Memory of SARS-CoV-2 Is Present in Patients with Primary Antibody Deficiencies for up to a Year after Vaccination.

Some studies have found increased coronavirus disease-19 (COVID-19)-related morbidity and mortality in patients with primary antibody deficiencies. Immunization against COVID-19 may, therefore, be particularly important in these patients. However, the durability of the immune response remains unclear in such patients. In this study, we evaluated the cellular and humoral response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens in a cross-sectional study of 32 patients with primary antibody deficiency (n = 17 with common variable immunodeficiency (CVID) and n = 15 with selective IgA deficiency) and 15 healthy controls. Serological and cellular responses were determined using enzyme-linked immunosorbent assay and interferon-gamma release assays. The subsets of B and T lymphocytes were measured using flow cytometry. Of the 32 patients, 28 had completed the vaccination regimen with a median time after vaccination of 173 days (IQR = 142): 27 patients showed a positive spike-peptide-specific antibody response, and 26 patients showed a positive spike-peptide-specific T-cell response. The median level of antibody response in CVID patients (5.47 ratio (IQR = 4.08)) was lower compared to healthy controls (9.43 ratio (IQR = 2.13)). No difference in anti-spike T-cell response was found between the groups. The results of this study indicate that markers of the sustained SARS-CoV-2 spike-specific immune response are detectable several months after vaccination in patients with primary antibody deficiencies comparable to controls.

Care of patients with inborn errors of immunity in thirty J Project countries between 2004 and 2021.

Introduction: The J Project (JP) physician education and clinical research collaboration program was started in 2004 and includes by now 32 countries mostly in Eastern and Central Europe (ECE). Until the end of 2021, 344 inborn errors of immunity (IEI)-focused meetings were organized by the JP to raise awareness and facilitate the diagnosis and treatment of patients with IEI. Results: In this study, meeting profiles and major diagnostic and treatment parameters were studied. JP center leaders reported patients' data from 30 countries representing a total population of 506 567 565. Two countries reported patients from JP centers (Konya, Turkey and Cairo University, Egypt). Diagnostic criteria were based on the 2020 update of classification by the IUIS Expert Committee on IEI. The number of JP meetings increased from 6 per year in 2004 and 2005 to 44 and 63 in 2020 and 2021, respectively. The cumulative number of meetings per country varied from 1 to 59 in various countries reflecting partly but not entirely the population of the respective countries. Altogether, 24,879 patients were reported giving an average prevalence of 4.9. Most of the patients had predominantly antibody deficiency (46,32%) followed by patients with combined immunodeficiencies (14.3%). The percentages of patients with bone marrow failure and phenocopies of IEI were less than 1 each. The number of patients was remarkably higher that those reported to the ESID Registry in 13 countries. Immunoglobulin (IgG) substitution was provided to 7,572 patients (5,693 intravenously) and 1,480 patients received hematopoietic stem cell therapy (HSCT). Searching for basic diagnostic parameters revealed the availability of immunochemistry and flow cytometry in 27 and 28 countries, respectively, and targeted gene sequencing and new generation sequencing was available in 21 and 18 countries. The number of IEI centers and experts in the field were 260 and 690, respectively. We found high correlation between the number of IEI centers and patients treated with intravenous IgG (IVIG) (correlation coefficient, cc, 0,916) and with those who were treated with HSCT (cc, 0,905). Similar correlation was found when the number of experts was compared with those treated with HSCT. However, the number of patients treated with subcutaneous Ig (SCIG) only slightly correlated with the number of experts (cc, 0,489) and no correlation was found between the number of centers and patients on SCIG (cc, 0,174). Conclusions: 1) this is the first study describing major diagnostic and treatment parameters of IEI care in countries of the JP; 2) the data suggest that the JP had tremendous impact on the development of IEI care in ECE; 3) our data help to define major future targets of JP activity in various countries; 4) we suggest that the number of IEI centers and IEI experts closely correlate to the most important treatment parameters; 5) we propose that specialist education among medical professionals plays pivotal role in increasing levels of diagnostics and adequate care of this vulnerable and still highly neglected patient population; 6) this study also provides the basis for further analysis of more specific aspects of IEI care including genetic diagnostics, disease specific prevalence, newborn screening and professional collaboration in JP countries.

Inborn error of immunity as the cause of recurrent pericarditis.

Familial Mediterranean fever (FMF) is an autoinflammatory disease caused by a pyrin dysfunction, leading to uncontrolled interleukin-1 production that triggers the attacks. Here we report a case of a 36-year-old female patient repeatedly admitted to the cardiology ward with recurrent episodes of pericarditis, with intervals of 1 and 2 months between the episodes. During the attacks, chest pain and fever were the only symptoms. Following the administration of steroids and non-steroidal anti-inflammatory drugs, the patient became afebrile. She also had lymphoma and thyroid carcinoma in anamnesis essential for differential diagnosis. Laboratory tests for infection and autoimmune disease were all negative, and the positron emission tomography-CT scan did not reveal lymphoma relapse. Genetic testing revealed a mutation in the MEFV gene. It is very rare for pericarditis to be the first and only manifestation of FMF.

Plasma neurofilament light chain as a potential biomarker in Charcot-Marie-Tooth disease.

BACKGROUND AND PURPOSE: Charcot-Marie-Tooth (CMT) disease is a chronic, slowly progressing disorder. The lack of specific disease progression biomarkers limits the execution of clinical trials. However, neurofilament light chain (NfL) has been suggested as a potential biomarker for peripheral nervous system disorders. METHODS: Ninety-six CMT disease patients and 60 healthy controls were enrolled in the study. Disease severity assessment included clinical evaluation with CMT Neuropathy Score version 2 (CMTNSv2). Blood plasma NfL concentrations were measured using the single-molecule array NfL assay. RESULTS: The NfL concentration was significantly higher in the CMT disease patient group than in the controls (p < 0.001). Of the CMT disease patients, those with type CMTX1 had a higher NfL level than those in the two other analysed subgroups (CMT1A and other CMT disease types) (p = 0.0498). The NfL concentration had a significant but weak correlation with the CMTNSv2 (rs  = 0.25, p = 0.012). In one CMT disease patient with an extremely elevated NfL level, overlap with chronic inflammatory demyelinating polyneuropathy was suspected. Receiver operating characteristic analysis showed that an NfL concentration of 8.9 pg/ml could be used to discriminate CMT disease patients from controls, with an area under the curve of 0.881. CONCLUSIONS: Our study confirmed that the plasma NfL concentration is significantly higher in CMT disease patients than in controls. Plasma NfL concentration was found to significantly, albeit weakly, reflect the clinical severity of CMT disease. In the future, NfL may be used, either individually or collaboratively, as a biomarker in the clinical context of suspected CMT disease; however, several issues need to be addressed first.

Neuroinflammatory Disease as an Isolated Manifestation of Hemophagocytic Lymphohistiocytosis.

Isolated neuroinflammatory disease has been described in case reports of familial hemophagocytic lymphohistiocytosis (FHL), but the clinical spectrum of disease manifestations, response to therapy and prognosis remain poorly defined. We combined an international survey with a literature search to identify FHL patients with (i) initial presentation with isolated neurological symptoms; (ii) absence of cytopenia and splenomegaly at presentation; and (iii) systemic HLH features no earlier than 3 months after neurological presentation. Thirty-eight (20 unreported) patients were identified with initial diagnoses including acute demyelinating encephalopathy, leukoencephalopathy, CNS vasculitis, multiple sclerosis, and encephalitis. Median age at presentation was 6.5 years, most commonly with ataxia/gait disturbance (75%) and seizures (53%). Diffuse multifocal white matter changes (79%) and cerebellar involvement (61%) were common MRI findings. CSF cell count and protein were increased in 22/29 and 15/29 patients, respectively. Fourteen patients progressed to systemic inflammatory disease fulfilling HLH-2004 criteria at a mean of 36.9 months after initial neurological presentation. Mutations were detected in PRF1 in 23 patients (61%), RAB27A in 10 (26%), UNC13D in 3 (8%), LYST in 1 (3%), and STXBP2 in 1 (3%) with a mean interval to diagnosis of 28.3 months. Among 19 patients who underwent HSCT, 11 neurologically improved, 4 were stable, one relapsed, and 3 died. Among 14 non-transplanted patients, only 3 improved or had stable disease, one relapsed, and 10 died. Isolated CNS-HLH is a rare and often overlooked cause of inflammatory brain disease. HLH-directed therapy followed by HSCT seems to improve survival and outcome.

Clinical Phenotyping and Biomarkers in Spinal and Bulbar Muscular Atrophy.

Background: Spinal and bulbar muscular atrophy (SBMA) or Kennedy disease [OMIM: 313200] is a rare X-linked neuromuscular disease. Patients commonly present with muscle cramps, tremors, leg weakness, dysarthria and dysphagia. Methods: We deeply phenotyped and evaluated the possible extent of affected systems in all patients with SBMA in Latvia (n = 5). In addition, neurophysiological studies and blood analyses were used to perform a molecular diagnosis and evaluate biochemical values. We analyzed neurofilament light (NfL) as a possible biomarker. Results: Neurological examination revealed typical SBMA clinical manifestations; all patients had small or large nerve fiber neuropathy. Three of five patients had increased neurofilament light levels. Conclusion: The study confirms the systemic involvement in patients suffering from SBMA. Increased NfL concentration was associated with either peripheral neuropathy or decreased body mass index. The complex phenotype of the disease should be kept in mind, as it could help to diagnose patients with SBMA.

The effect of different workplace nanoparticles on the immune systems of employees.

Currently, nanoparticles are widely present in the environment and are being used in various industrial technologies. Nanoparticles affect immune functions, causing different immune responses. The aim of the current study was to evaluate several cytokines, interleukin (IL)-1b, IL-6, IL-8, tumour necrosis factor-a (TNF-α), interferon-γ, adhesive molecule sICAM-1, macrophage inhibitory protein 1a (MIP1a) and secretory immunoglobulin A, in nasal lavage fluid and in the peripheral blood of healthy subjects exposed to workplace nanoparticles. Thirty-six employees from three different environments were examined: 12 from a metalworking company, 12 from a woodworking company and 12 office workers. The nanoparticles in the different workplaces were detected in the air in the immediate vicinity of the employees. The particle number concentration and surface area values were significantly higher in the workplaces of the metal- and woodworking industries, but concentrations of mass were lower (the measurements were performed by an electrical low-pressure impactor ELPI+). Energy dispersive X-ray spectroscopy (EDS, an attachment to a high-resolution SEM) was used to provide elemental analysis or chemical characterization of the dust particles in a low-vacuum field-free mode operating at a potential of 15 kV spot 3.0. The technique used provided quantitative and spatial analyses of the distribution of elements through mapping (two to three parallel measurements) and point analysis (four to five parallel measurements). Samples from the metal industry contained more ultramicroscopic and nanometric particles, e.g. toxic metals such as Zn, Mn and Cr, and fewer microscopic dust particles. The nasal lavage and peripheral blood were taken at the beginning and the end of the working week, when immune indices were measured. Our data showed a statistically significant increased level of the pro-inflammatory cytokine TNF-α in serum in both exposed groups compared with office workers as well as a higher level of TNF-α in workers from the woodworking company compared with the metalworking employees. We found an elevated level of IL-6 in the exposed groups as well as an elevated level of IL-8 in the nasal lavage in woodworking employees after work.