B-cell and T-cell receptor repertoire in chronic inflammatory demyelinating polyneuropathy, a prospective cohort study.

The immunopathophysiological mechanisms underlying chronic inflammatory demyelinating polyneuropathy (CIDP) in an individual patient are largely unknown. Better understanding of these mechanisms may aid development of biomarkers and targeted therapies. Both B- and T-cell dominant mechanisms have been implicated. We therefore investigated whether B-cell and T-cell receptor (BCR/TCR) repertoires might function as immunological biomarkers in CIDP. In this prospective cohort study, we longitudinally sampled peripheral blood of CIDP patients in three different phases of CIDP: starting induction treatment (IT), starting withdrawal from IVIg maintenance treatment (MT), and patients in remission (R). BCR and TCR repertoires were analyzed using RNA based high throughput sequencing. In baseline samples, the number of total clones, the number of dominant BCR and TCR clones and their impact on the repertoire was similar for patients in the IT, MT, and remission groups compared with healthy controls. Baseline samples in the IT or MT did not predict treatment response or potential relapse at follow-up. Treatment responders in the IT group showed a potential IVIg-induced increase in the number of dominant BCR clones and their impact at follow-up (baseline1.0 [IQR 1.0-2.8] vs. 6 m 3.5 [0.3-6.8]; P < .05, Wilcoxon test). Although the BCR repertoire changed over time, the TCR repertoire remained robustly stable. We conclude that TCR and BCR repertoire distributions do not predict disease activity, treatment response or response to treatment withdrawal.

Spinning straw into gold: description of a disruptive rheumatology research platform inspired by the COVID-19 pandemic.

Clinical research projects often use traditional methods in which data collection and signing informed consent forms rely on patients' visits to the research institutes. However, during challenging times when the medical community is in dire need of information, such as the current COVID-19 pandemic, it becomes more urgent to use digital platforms that can rapidly collect data on large numbers of patients. In the current manuscript, we describe a novel digital rheumatology research platform, consisting of almost 5000 patients with autoimmune diseases and healthy controls, that was set up rapidly during the COVID-19 pandemic, but which is sustainable for the future. Using this platform, uniform patient data can be collected via questionnaires and stored in a single database readily available for analysis. In addition, the platform facilitates two-way communication between patients and researchers, so patients become true research partners. Furthermore, blood collection via a finger prick for routine and specific laboratory measurements has been implemented in this large cohort of patients, which may not only be applicable for research settings but also for clinical care. Finally, we discuss the challenges and potential future applications of our platform, including supplying tailored information to selected patient groups and facilitation of patient recruitment for clinical trials.

Intestinal CD8+ T cell responses are abundantly induced early in human development but show impaired cytotoxic effector capacities.

Gastrointestinal viral infections are a major global cause of disease and mortality in infants. Cytotoxic CD8+ T cells are critical to achieve viral control. However, studies investigating the development of CD8+ T cell immunity in human tissues early in life are lacking. Here, we investigated the maturation of the CD8+ T cell compartment in human fetal, infant and adult intestinal tissues. CD8+ T cells exhibiting a memory phenotype were already detected in fetal intestines and increased after birth. Infant intestines preferentially harbored effector CCR7-CD45RA-CD127-KLRG1+/- CD8+ T cells compared to tissue-resident memory CD69+CD103+CD8+ T cells detected in adults. Functional cytotoxic capacity, including cytokine and granzyme B production of infant intestinal effector CD8+ T cells was, however, markedly reduced compared to adult intestinal CD8+ T cells. This was in line with the high expression of the inhibitory molecule PD-1 by infant intestinal effector CD8+ T cells. Taken together, we demonstrate that intestinal CD8+ T cell responses are induced early in human development, however exhibit a reduced functionality. The impaired CD8+ T cell functionality early in life contributes to tolerance during foreign antigen exposure after birth, however functions as an immune correlate for the increased susceptibility to gastrointestinal viral infections in infancy.

IgG4:IgG RNA ratio differentiates active disease from remission in granulomatosis with polyangiitis: a new disease activity marker? A cross-sectional and longitudinal study.

OBJECTIVES: An important limitation in granulomatosis with polyangiitis (GPA) is the lack of disease activity markers. Immunoglobulin G4-positive (IgG4+) B cells and plasma cells are implicated in the pathogenesis of GPA. We hypothesized that the presence of these cells in peripheral blood could serve as disease activity parameter in GPA. METHODS: We included 35 proteinase 3-antineutrophil cytoplasmic antibodies-positive patients with GPA in a cross-sectional study. Active disease was defined as Birmingham Vasculitis Activity Score (BVAS) ≥ 3 (n = 15), remission as BVAS of 0 (n = 17), and low disease activity (LDA) as BVAS of 1-2 and clinical remission (n = 3). Healthy subjects (n = 10), patients with systemic lupus erythematosus (n = 24), and patients with rheumatoid arthritis (n = 19) functioned as control subjects. An additional longitudinal study was performed in ten patients with GPA. Using a validated qPCR test, we measured the IgG4:IgG RNA ratio in all groups and compared the results with known biomarkers. RESULTS: The median qPCR score was higher in active GPA (21.4; IQR 12.1-29.6) than in remission/LDA (3.3; IQR 1.6-5.6) (Mann-Whitney U test, p < 0.0001) and outperformed other known disease activity parameters in detecting activity. A cutoff qPCR score of 11.2% differentiated active disease from remission/LDA accurately (AUC 0.993). The qPCR test correlated well with the BVAS (Spearman r = 0.77, p < 0.0001). In the longitudinal study, a decrease in BVAS correlated with qPCR score reduction (paired t test, p < 0.05). CONCLUSIONS: The IgG4:IgG RNA ratio in GPA accurately distinguishes active disease from remission and correlates well with disease activity in these single-center studies. If these results are confirmed in larger longitudinal studies, this test might help to steer treatment decisions in patients with GPA.

Why don't neurosurgery patients return for neuropsychological follow-up? Predictors for voluntary appointment keeping and reasons for cancellation.

Neuropsychological follow-up appointments are important for patients who have had intracranial surgery because cognitive deficits are common in this population and prognosis is not always optimistic. Unfortunately some patients cancel or do not show up. The current study attempted to identify predictors of non-attendance in this population. A total of 428 patients recruited over 2 years with a scheduled neuropsychological follow-up appointment after intracranial surgery in the St. Elisabeth Hospital, Tilburg, The Netherlands were included. Demographic, clinical, and other miscellaneous variables were extracted from medical records. Of this total population, 42% were non-attenders. The predictors of non-attendance were as follows: patients who had subdural hematomas and/or malignant tumors (compared to those who had other diagnoses prior to intracranial surgery); those who had been transferred to another hospital (compared to those sent home); those who had been referred for further medical treatment before the appointment; a shorter time interval between discharge and follow-up appointment; and finally, if the patient's home was further away from the hospital. Patients who undergo intracranial surgery are a very heterogeneous group with different needs. Neuropsychological follow-up after surgery may be important for some patients (the better-functioning and/or those with cognitive complaints) but perhaps not for others (those with more severe prognoses and/or no complaints). We provide suggestions which should increase attendance in those who could benefit from follow-up neuropsychological assessment.

Rheumatoid arthritis synovial tissue harbours dominant B-cell and plasma-cell clones associated with autoreactivity.

OBJECTIVE: To identify potential autoreactive B-cell and plasma-cell clones by quantitatively analysing the complete human B-cell receptor (BCR) repertoire in synovium and peripheral blood in early and established rheumatoid arthritis (RA). METHODS: The BCR repertoire was screened in synovium and blood of six patients with early RA (ERA) (<6 months) and six with established RA (ESRA) (>20 months). In two patients, the repertoires in different joints were compared. Repertoires were analysed by next-generation sequencing from mRNA, generating >10 000 BCR heavy-chain sequence reads per sample. For each clone, the degree of expansion was calculated as the percentage of the total number of reads encoding the specific clonal sequence. Clones with a frequency ≥ 0.5% were considered dominant. RESULTS: Multiple dominant clones were found in inflamed synovium but hardly any in blood. Within an individual patient, the same dominant clones were detected in different joints. The majority of the synovial clones were class-switched; however, the fraction of clones that expressed IgM was higher in ESRA than ERA patients. Dominant synovial clones showed autoreactive features: in ERA in particular the clones were enriched for immunoglobulin heavy chain gene segment V4-34 (IGHV4-34) and showed longer CDR3 lengths. Dominant synovial clones that did not encode IGHV4-34 also had longer CDR3s than peripheral blood. CONCLUSIONS: In RA, the synovium forms a niche where expanded--potentially autoreactive--B cells and plasma cells reside. The inflamed target tissue, especially in the earliest phase of disease, seems to be the most promising compartment for studying autoreactive cells.

Deep sequencing of antiviral T-cell responses to HCMV and EBV in humans reveals a stable repertoire that is maintained for many years.

CD8(+) T-cell responses against latent viruses can cover considerable portions of the CD8(+) T-cell compartment for many decades, yet their initiation and maintenance remains poorly characterized in humans. A key question is whether the clonal repertoire that is raised during the initial antiviral response can be maintained over these long periods. To investigate this we combined next-generation sequencing of the T-cell receptor repertoire with tetramer-sorting to identify, quantify and longitudinally follow virus-specific clones within the CD8(+) T-cell compartment. Using this approach we studied primary infections of human cytomegalovirus (hCMV) and Epstein Barr virus (EBV) in renal transplant recipients. For both viruses we found that nearly all virus-specific CD8(+) T-cell clones that appeared during the early phase of infection were maintained at high frequencies during the 5-year follow-up and hardly any new anti-viral clones appeared. Both in transplant recipients and in healthy carriers the clones specific for these latent viruses were highly dominant within the CD8(+) T-cell receptor Vß repertoire. These findings suggest that the initial antiviral response in humans is maintained in a stable fashion without signs of contraction or changes of the clonal repertoire.

Inflamed target tissue provides a specific niche for highly expanded T-cell clones in early human autoimmune disease.

OBJECTIVE: To profile quantitatively the T-cell repertoire in multiple joints and peripheral blood of patients with recent onset (early) or established rheumatoid arthritis (RA) using a novel next-generation sequencing protocol to identify potential autoreactive clones. METHODS: Synovium of patients with recent onset (early) RA (<6 months) (n=6) or established RA (>18 months) (n=6) was screened for T-cell clones by sequencing over 10 000 T-cell receptors (TCR) per sample. T cells from paired blood samples were analysed for comparison. From two patients synovial T cells were obtained from multiple inflamed joints. The degree of expansion of each individual clone was based on its unique CDR3 sequence frequency within a sample. Clones with a frequency of over 0.5% were considered to be highly expanded clones (HEC). RESULTS: In early RA synovium, the T-cell repertoire was dominated by 35 HEC (median, range 2-70) accounting for 56% of the TCR sequenced. The clonal dominance in the synovium was patient specific and significantly greater than in established RA (median of 11 HEC (range 5-24) in established RA synovium accounting for 9.8% of T cells; p<0.01). 34% (range 28-40%) of the most expanded T-cell clones were shared between different joints in the same patients, compared with only 4% (range 0-8%) between synovium and blood (p=0.01). CONCLUSIONS: In RA, a systemic autoimmune disease, the inflamed synovium forms a niche for specific expanded T-cell clones, especially in early disease. This suggests that, at least in RA, autoreactive T cells should be addressed specifically in the inflamed tissue, preferably in the early phase of the disease.

Different stages of rheumatoid arthritis: features of the synovium in the preclinical phase.

BACKGROUND: The aetiology of rheumatoid arthritis (RA), a prototype immune-mediated inflammatory disorder, is poorly understood. It is currently unknown whether the disease process starts in the synovium, the primary target of RA, or at other sites in the body. OBJECTIVE: To examine, in a prospective study, the presence of synovitis in people with an increased risk of developing RA. METHODS: Thirteen people without evidence of arthritis, who were positive for IgM rheumatoid factor and/or anticitrullinated protein antibodies, were included in the study. To evaluate synovial inflammatory changes, all participants underwent dynamic contrast-enhanced MRI and arthroscopic synovial biopsy sampling of a knee joint at inclusion. Results were compared with knee MRI data and synovial biopsy data of 6 and 10 healthy controls, respectively. RESULTS: MRI findings evaluated by measurement of maximal enhancement, rate of enhancement, synovial volume and enhancement shape curve distribution were similar between the autoantibody-positive subjects and the healthy controls. Consistent with these findings, all but one autoantibody-positive subject showed very low scores for phenotypic markers, adhesion molecules and vascularity, all in the same range as those in normal controls. The one person with higher scores had patellofemoral joint space narrowing. CONCLUSION: Subclinical inflammation of the synovium does not coincide with the appearance of serum autoantibodies during the pre-RA stage. Thus, systemic autoimmunity precedes the development of synovitis, suggesting that a 'second hit' is involved. This study supports the rationale for exploring preventive strategies aimed at interfering with the humoral immune response before synovial inflammation develops.

Enhanced gene transfer to arthritic joints using adeno-associated virus type 5: implications for intra-articular gene therapy.

BACKGROUND: Gene therapy of the joint has great potential as a new therapeutic approach for the treatment of rheumatoid arthritis (RA). The vector chosen is of crucial importance for clinical success. OBJECTIVE: To investigate the tropism and transduction efficiency in arthritic joints in vivo, and in synovial cells in vitro, using five different serotypes of recombinant adeno-associated virus (rAAV) encoding beta-galactosidase or green fluorescent protein genes. METHODS: rAAV was injected into the ankle joints of rats with adjuvant arthritis after the onset of disease. Synovial tissue was examined at different time points for beta-galactosidase protein and gene expression by in situ staining and polymerase chain reaction (PCR) analysis, respectively. In addition, the ability of rAAV to transduce primary human fibroblast-like synoviocytes from patients with RA was investigated in vitro. RESULTS: Intra-articular injection of the rAAV5 serotype resulted in the highest synovial transduction, followed by much lower expression using rAAV2. Expression of the transgene was already detectable 7 days after injection and lasted for at least 4 weeks. Only background staining was seen for serotypes 1, 3, and 4. Importantly, there was a minimal humoral immune response to rAAV5 compared with rAAV2. Additionally, it was found that both rAAV2 and rAAV5 can efficiently transduce human fibroblast-like synoviocytes obtained from patients with RA. CONCLUSION: Intra-articular rAAV mediated gene therapy in RA might be improved by using rAAV5 rather than other serotypes.