Abatacept increases T cell exhaustion in early RA individuals who carry HLA risk alleles

Exhausted CD8 T cells (TEX) are associated with worse outcome in cancer yet better outcome in autoimmunity. Building on our past findings of increased TIGIT+KLRG1+ TEX with teplizumab therapy in type 1 diabetes (T1D), in the absence of treatment we found that the frequency of TIGIT+KLRG1+ TEX is stable within an individual but differs across individuals in both T1D and healthy control (HC) cohorts. This TIGIT+KLRG1+ CD8 TEX population shares an exhaustion-associated EOMES gene signature in HC, T1D, rheumatoid arthritis (RA), and cancer subjects, expresses multiple inhibitory receptors, and is hyporesponsive in vitro, together suggesting co-expression of TIGIT and KLRG1 may broadly define human peripheral exhausted cells. In HC and RA subjects, lower levels of EOMES transcriptional modules and frequency of TIGIT+KLRG1+ TEX were associated with RA HLA risk alleles (DR0401, 0404, 0405, 0408, 1001) even when considering disease status and cytomegalovirus (CMV) seropositivity. Moreover, the frequency of TIGIT+KLRG1+ TEX was significantly increased in RA HLA risk but not non-risk subjects treated with abatacept (CTLA4Ig). The DR4 association and selective modulation with abatacept suggests that therapeutic modulation of TEX may be more effective in DR4 subjects and TEX may be indirectly influenced by cellular interactions that are blocked by abatacept.

Exploration of Tumor Biopsy Gene Signatures to Understand the Role of the Tumor Microenvironment in Outcomes to Lisocabtagene Maraleucel

In the TRANSCEND NHL 001 study, 53% of patients with relapsed/refractory large B-cell lymphoma (LBCL) treated with lisocabtagene maraleucel (liso-cel) achieved a complete response (CR). To determine characteristics of patients who did and did not achieve a CR, we examined the tumor biology and microenvironment from lymph node tumor biopsies. LBCL biopsies from liso-cel-treated patients were taken pretreatment and ∼11 days posttreatment for RNA sequencing (RNA-seq) and multiplex immunofluorescence (mIF). We analyzed gene expression data from pretreatment biopsies (N = 78) to identify gene sets enriched in patients who achieved a CR to those with progressive disease. Pretreatment biopsies from month-3 CR patients displayed higher expression levels of T-cell and stroma-associated genes, and lower expression of cell-cycle genes. To interpret whether LBCL samples were "follicular lymphoma (FL)-like," we constructed an independent gene expression signature and found that patients with a higher "FL-like" gene expression score had longer progression-free survival (PFS). Cell of origin was not associated with response or PFS, but double-hit gene expression was associated with shorter PFS. The day 11 posttreatment samples (RNA-seq, N = 73; mIF, N = 53) had higher levels of chimeric antigen receptor (CAR) T-cell densities and CAR gene expression, general immune infiltration, and immune activation in patients with CR. Further, the majority of T cells in the day 11 samples were endogenous. Gene expression signatures in liso-cel-treated patients with LBCL can inform the development of combination therapies and next-generation CAR T-cell therapies.

Phase 1 TRANSCEND CLL 004 study of lisocabtagene maraleucel in patients with relapsed/refractory CLL or SLL

Bruton tyrosine kinase inhibitors (BTKi) and venetoclax are currently used to treat newly diagnosed and relapsed/refractory chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). However, most patients eventually develop resistance to these therapies, underscoring the need for effective new therapies. We report results of the phase 1 dose-escalation portion of the multicenter, open-label, phase 1/2 TRANSCEND CLL 004 (NCT03331198) study of lisocabtagene maraleucel (liso-cel), an autologous CD19-directed chimeric antigen receptor (CAR) T-cell therapy, in patients with relapsed/refractory CLL/SLL. Patients with standard- or high-risk features treated with ≥3 or ≥2 prior therapies, respectively, including a BTKi, received liso-cel at 1 of 2 dose levels (50 × 106 or 100 × 106 CAR+ T cells). Primary objectives included safety and determining recommended dose; antitumor activity by 2018 International Workshop on CLL guidelines was exploratory. Minimal residual disease (MRD) was assessed in blood and marrow. Twenty-three of 25 enrolled patients received liso-cel and were evaluable for safety. Patients had a median of 4 (range, 2-11) prior therapies (100% had ibrutinib; 65% had venetoclax) and 83% had high-risk features including mutated TP53 and del(17p). Seventy-four percent of patients had cytokine release syndrome (9% grade 3) and 39% had neurological events (22% grade 3/4). Of 22 efficacy-evaluable patients, 82% and 45% achieved overall and complete responses, respectively. Of 20 MRD-evaluable patients, 75% and 65% achieved undetectable MRD in blood and marrow, respectively. Safety and efficacy were similar between dose levels. The phase 2 portion of the study is ongoing at 100 × 106 CAR+ T cells. This trial was registered at clinicaltrials.gov as NCT03331198.

449 Concurrent ibrutinib enhances T cell function in patients with chronic lymphocytic leukemia (CLL) treated with lisocabtagene maraleucel (liso-cel), a chimeric antigen receptor (CAR) T cell therapy

Background

CLL is an incurable hematologic malignancy characterized by progressive accumulation of clonally derived CD19+ B-cell lymphocytes. CAR T cell therapies are promising treatments but inherent T cell dysfunction has limited their development in CLL. Preclinical studies suggest ibrutinib may modulate CAR T cells directly to improve their function independently of antitumor effects. Liso-cel is an autologous, CD19-directed, defined composition, 4–1BB CAR T cell product administered at equal target doses of CD8+ and CD4+ CAR+ T cells. The ongoing TRANSCEND CLL 004 study evaluates the efficacy and safety of liso-cel alone (monotherapy) or with concurrent ibrutinib (combination) in relapsed/refractory (R/R) CLL.1 We investigated the effect of ibrutinib on post-infusion CAR+ and endogenous T cells relative to monotherapy using a novel cell-sorting, low-input RNA-seq method for analysis of patient cells beyond peak expansion, including 1 and 2 months after liso-cel infusion.

Methods

CAR+ and endogenous T cells from patients in TRANSCEND CLL 004 (NCT03331198; monotherapy, n=16; combination, n=19) were isolated from peripheral blood mononuclear cells by fluorescence-activated cell sorting. RNA-seq was performed using cell lysate as input material. CAR+ T cell pharmacokinetics were assessed by flow cytometry. Serum interleukin-6 was measured by electrochemiluminescent multiplex immunoassay. Minimal residual disease (<10−4) was evaluated by flow cytometry in peripheral blood and next-generation sequencing in bone marrow.

Results

Gene set enrichment analyses revealed positive enrichment of cell proliferation-associated gene sets and negative enrichment of inflammation-associated gene sets at peak expansion in CAR+ T cells from combination relative to monotherapy patients. Similar, but less marked, proliferation- and inflammation-associated gene expression changes were also observed in endogenous T cells. Accordingly, increased CAR+ T cell expansion and reduced serum interleukin-6 were observed in combination patients. In addition, an independently derived CLL ibrutinib gene expression score2 was increased and sustained in CAR+ and endogenous T cells from combination but not monotherapy patients over time. A higher ibrutinib score trended with a higher rate of undetectable minimal residual disease, longer progression-free survival (PFS), and longer duration of response. Lastly, a T cell exhaustion-related gene signature was significantly reduced in CAR+ but not endogenous T cells with combination treatment, and this reduction was associated with improved PFS.

Conclusions

Concurrent ibrutinib treatment in patients with R/R CLL resulted in measurable effects in CAR+ and endogenous T cells, including changes in gene signatures related to proliferation, inflammation, and T cell exhaustion. These changes were associated with enhanced CAR T cell function and efficacy.

Acknowledgements

We would like to thank the patients, caregivers, investigators, and study personnel. This study was funded by Juno Therapeutics, a Bristol-Myers Squibb Company. All authors contributed to and approved the abstract; writing and editorial assistance were provided by Allison Green, PhD, of The Lockwood Group (Stamford, CT, USA), funded by Bristol Myers Squibb.

Trial Registration

NCT03331198

References

Wierda WG, Dorritie KA, Munoz J, et al. TRANSCEND CLL 004: phase 1 cohort of lisocabtagene maraleucel (liso-cel) combined with ibrutinib (IBR) for patients (pts) with R/R CLL/SLL. Hematol Oncol 2021;39(S2):141–143.

Rendeiro AF, Krausgruber T, Fortelny N, et al. Chromatin mapping and single-cell immune profiling define the temporal dynamics of ibrutinib response in CLL. Nat Commun 2020;11:577.

Ethics Approval

This study used patient cells obtained from a clinical trial that was done in accordance with with the Declaration of Helsinki, International Conference on Harmonization Good Clinical Practice guidelines, institutional review boards at participating institutions approved the study protocol and amendments, and all patients provided written informed consent.

The impact of COVID-19 on epilepsy care: Perspectives from UK healthcare workers

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We surveyed UK healthcare workers (HCWs) involved in the care of people with epilepsy.

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During the pandemic, 70% of respondents held most consultations remotely.

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HCWs experienced increased mental strain and concern for colleagues/family members.

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HCWs reported being less confident in diagnosing epilepsy remotely.

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Clinicians were more reluctant to withdraw seizure medications during the pandemic.

The COVID-19 pandemic has created an immense pressure on healthcare providers, resulting in a shift to remote consultations and the redeployment of healthcare workers (HCWs). We present survey data from the United Kingdom (UK) HCWs to outline how changes in healthcare provision impact clinicians' wellbeing and ability to provide adequate care. We designed an online survey to gather the experiences of HCWs providing care to people with epilepsy. We received seventy-nine responses from UK-based HCWs, of whom 43% reported an impact on their mental health. Changes to service delivery have resulted in 71% of clinicians performing > 75% of their consultations remotely. Diagnosing and treating epilepsy has changed, with a fifth of respondents being significantly less confident in diagnosing epilepsy. Ultimately, these results show that COVID-19 has had an overall negative impact on HCWs and their ability to provide epilepsy care. These results must be considered when reorganizing health services to ensure optimal outcomes for people with epilepsy.

Lisocabtagene maraleucel (liso-cel) for treatment of second-line (2L) transplant noneligible (TNE) relapsed/refractory (R/R) aggressive large B-cell non-Hodgkin lymphoma (NHL): Updated results from the PILOT study

8040

Background: Patients (pts) with aggressive large B-cell NHL who are R/R after first-line immunochemotherapy and not eligible for high-dose chemotherapy and HSCT have a poor prognosis and no established standard of care. The ongoing, open-label phase 2 PILOT study is the first to assess the safety and efficacy of liso-cel, an investigational, CD19-directed, defined composition, 4-1BB CAR T cell product infused at equal target doses of CD8+ and CD4+ CAR+ T cells, as 2L therapy in TNE pts (NCT03483103). Methods: Eligible pts had aggressive R/R diffuse large B-cell lymphoma NOS (de novo or transformed follicular lymphoma [FL]), high-grade B-cell lymphoma, or FL grade 3B with 1 line of prior therapy containing an anthracycline and anti-CD20 agent. Pts were deemed TNE by meeting ≥1 criteria: age ≥70 y, ECOG PS 2, or impaired organ function (DLCO ≤60% [but SaO2 ≥92% and CTCAE ≤1 dyspnea], LVEF ≥40% to < 50%, creatinine clearance > 30 to < 60 mL/min, or AST/ALT > 2 to ≤5 × ULN). Liso-cel (100 × 106 CAR+ T cells) was administered 2–7 days after lymphodepletion (LD) with fludarabine/cyclophosphamide. The primary endpoint is ORR; key secondary endpoints are AEs and CR rate. Results: At data cutoff, 25 pts had LD followed by liso-cel infusion. Pt characteristics are summarized in the Table. Overall, 48% (n = 12) had high tumor burden and 48% were primary refractory. 18/25 (72%) pts had grade ≥3 treatment-emergent AEs, 40% of which were cytopenias. No grade 5 AEs occurred within the first 30 days after liso-cel. Five pts (20%) had cytokine release syndrome (CRS) and 3 (12%) had neurological events (NEs). No grade 3/4 CRS was observed; 2 pts (8%) had grade 3/4 NEs. Five pts (20%) received tocilizumab and/or dexamethasone for CRS/NEs. At a median follow-up of 3.5 mo, the ORR was 80% (95% CI, 59–93; n = 20); 48% of pts (n = 12) achieved CR. Conclusions: These interim data suggest that elderly and/or comorbid pts with R/R aggressive large B-cell NHL, who are not eligible for high-dose chemotherapy and HSCT, can receive 2L liso-cel with similar safety and efficacy to 3L+ pts as previously reported (Abramson, ASH 2019 #241). Updated data with longer follow-up will be presented. Clinical trial information: NCT03483103 . [Table: see text]

Efficient CRISPR/Cas9 Disruption of Autoimmune-Associated Genes Reveals Key Signaling Programs in Primary Human T Cells

Risk of autoimmunity is associated with multiple genetic variants. Genome-wide association studies have linked single-nucleotide polymorphisms in the phosphatases PTPN22 (rs2476601) and PTPN2 (rs1893217) to increased risk for multiple autoimmune diseases. Previous mouse studies of loss of function or risk variants in these genes revealed hyperactive T cell responses, whereas studies of human lymphocytes revealed contrasting phenotypes. To better understand this dichotomy, we established a robust gene editing platform to rapidly address the consequences of loss of function of candidate genes in primary human CD4+ T cells. Using CRISPR/Cas9, we obtained efficient gene disruption (>80%) of target genes encoding proteins involved in Ag and cytokine receptor signaling pathways including PTPN22 and PTPN2 Loss-of-function data in all genes studied correlated with previous data from mouse models. Further analyses of PTPN2 gene-disrupted T cells demonstrated dynamic effects, by which hyperactive IL-2R signaling promoted compensatory transcriptional events, eventually resulting in T cells that were hyporesponsive to IL-2. These results imply that altered phosphatase activity promotes evolving phenotypes based on Ag experience and/or other programming signals. This approach enables the discovery of molecular mechanisms modulating risk of autoimmunity that have been difficult to parse in traditional mouse models or cross-sectional human studies.

TRANSCEND CLL 004: Minimal residual disease (MRD) negative responses after lisocabtagene maraleucel (Liso-Cel; JCAR017), a CD19-directed CAR T cell product, in patients (pts) with relapsed/refractory chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL)

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Background: Eradication of MRD in CLL patients may be necessary for deep and durable responses. We assessed safety, pharmacokinetics, and efficacy of liso-cel, an investigational, anti-CD19 CAR T cell product administered as a defined composition of CD4+/CD8+ CAR T cells, in the ongoing phase 1/2 TRANSCEND CLL 004 study. Methods: Eligible pts had CLL/SLL, received ≥2 prior lines of therapy (including Bruton’s tyrosine kinase inhibitors [BTKi] unless medically contraindicated), and had ECOG PS ≤1. Post lymphodepleting chemotherapy, pts received liso-cel infusion at either dose level (DL)1 = 50 × 106 or DL2 = 100 × 106 total CAR+ T cells. Patients were monitored for dose-limiting toxicities (DLTs). Response was assessed by iwCLL 2008 criteria. MRD was assessed by flow cytometry in blood (10−4) and by NGS in bone marrow (BM; 10−6). Results: At data cutoff, 16 pts received liso-cel: DL1, n = 6; DL2, n = 10. 75% of pts had high-risk features ( TP53 mutation, complex karyotype, or del17p); 100% had prior ibrutinib and 50% had prior venetoclax. Median (range) number of prior lines of therapy was 4.5 (2‒11). There was 1 DLT of grade (G) 4 hypertension (DL2). The most common G3/4 treatment-emergent adverse events were cytopenias (thrombocytopenia, 75%; anemia, 69%; neutropenia, 63%; leukopenia, 56%). 1 pt had G3 cytokine release syndrome (CRS); 3 pts had G3 neurological events (NE). Best overall response rate (ORR) in 15 evaluable pts was 87% (13/15). 7 pts (47%) achieved complete remission with/without complete blood count recovery (CR/CRi). ORR at 6 mo was 83% (5/6). 10/15 pts (67%) achieved undetectable MRD (uMRD) in blood by day 30 and in 7/8 pts (88%) in BM. MRD-negative CRs were seen in patients who had failed both BTKi and venetoclax. Median time to peak blood CAR+ T cell level was 16 days (4‒30). Conclusions: In this study of heavily pretreated pts with standard- and high-risk CLL/SLL and previous ibrutinib treatment, liso-cel-related toxicities (ie, CRS and NEs), were manageable. Pts rapidly achieved CR/CRi and uMRD. Additional follow-up will be presented. Clinical trial information: NCT03331198.

Circulating integrin alpha4/beta7+ lymphocytes targeted by vedolizumab have a pro-inflammatory phenotype

Integrin alpha4/beta7 on circulating lymphocytes identifies them as gut-tropic, and can be targeted by the humanized antibody vedolizumab to treat inflammatory bowel disease (IBD). We found lymphocytes expressing alpha4/beta7 were significantly more responsive to the pro-inflammatory cytokines IL-6, IL-7, and IL-21, and less responsive to the regulatory T cell (Treg)-supporting cytokine IL-2. Alpha4/beta7 was expressed by a smaller percent of FOXP3 + Helios+ thymically-derived Tregs (tTregs) than FOXP3 + Helios- peripherally-derived Tregs (pTregs) or FOXP3- effector T cells. Integrin alpha4/beta7+ CD4 T cells were also rare among cells expressing the Th2 marker CRTh2, but enriched in cells bearing the circulating T follicular helper cell marker CXCR5. Thus the effect of this anti-integrin therapy on the mucosal immune system may be more qualitative than quantitative, and selectively replace pro-inflammatory effector cells with Tregs and Th2 cells to facilitate immune tolerance in the mucosa without globally depleting lymphocytes from the intestinal mucosa.

Remodeling T cell compartments during anti-CD3 immunotherapy of type 1 diabetes

The immunological mechanism(s) of action whereby teplizumab preserves C-peptide levels in the progression of patients with recent onset type 1 diabetes (T1D) is still not well understood. In the present study, we evaluated the kinetics of T cell modulation in peripheral blood following two 14-day courses of teplizumab therapy one year apart in recent onset T1D participants in the AbATE clinical trial. Transient rises in PD-1+Foxp3+ Treg and potentially anergic (CD57-KLRG1-PD-1+) cells in the circulating CD4 T cell compartment were paralleled by more profound increases in circulating CD8 T cells with traits of exhaustion (CD57-KLRG1+PD-1+, TIGIT+KLRG1+, and persistent down-modulation of CD127). The observed phenotypic changes across cell types were associated with favorable response to treatment in the subgroup of study participants that did not develop anti-drug antibodies after the first course of therapy. These findings provide new insights on the duration and complexity of T cell modulation with teplizumab therapy in recent onset T1D, and in addition, suggest that coordinated immune mechanisms of tolerance that favor CD4 Treg function and restrain CD4 non-Treg and CD8 T cell activation may contribute to treatment success.

Attenuated IL-2R signaling in CD4 memory T cells of T1D subjects is intrinsic and dependent on activation state

The IL-2/IL-2R pathway is implicated in type 1 diabetes (T1D). While its role in regulatory T cell (Treg) biology is well characterized, mechanisms that influence IL-2 responses in effector T cells (Teff) are less well understood. We compared IL-2 responses in 95 healthy control and 98 T1D subjects. In T1D, low IL-2 responsiveness was most pronounced in memory Teff. Unlike Treg, CD25 expression did not influence the Teff responses. Reduced IL-2 responses in memory Teff were not rescued by resting, remained lower after activation and proliferation, and were absent in type 2 diabetes. Comparing basal IL-2 responses in resting versus activated cells, memory Teff displayed lower, but more sustained, responses to IL-2 overtime. These results suggest that T1D-associated defects in the Teff compartment are due to intrinsic factors related to activation. Evaluation of both Teff and Treg IL-2R signaling defects in T1D subjects may inform selection of therapies.

Partial exhaustion of CD8 T cells and clinical response to teplizumab in new-onset type 1 diabetes

Biologic treatment of T1D typically results in transient stabilization of C-peptide levels (a surrogate for endogenous insulin secretion) in some patients, followed by progression at the same rate as in untreated control groups. Here, we used integrated systems biology and flow cytometry approaches with clinical trial blood samples to elucidate pathways associated with C-peptide stabilization in T1D subjects treated with the anti-CD3 monoclonal antibody teplizumab. We identified a population of CD8 T cells that accumulated in subjects with the best response to treatment (responders) and showed that these cells phenotypically resembled exhausted T cells by expressing high levels of the transcription factor EOMES, effector molecules, and multiple inhibitory receptors (IRs), including TIGIT and KLRG1. These cells expanded after treatment, with levels peaking after 3-6 months. To functionally characterize these exhausted-like T cells, we isolated memory CD8 TIGIT+KLRG1+ T cells from responders and showed that they exhibited expanded TCR clonotypes, indicative of prior in vivo expansion; recognized a broad-based spectrum expressed of environmental and auto-antigens; and were hypo-proliferative during polyclonal stimulation, increasing expression of IR genes and decreasing cell cycle genes. Triggering these cells with a recombinant ligand for TIGIT during polyclonal stimulation further downregulated their activation, demonstrating their exhausted phenotype was not terminal. These findings identify and functionally characterize a partially exhausted cell type associated with response to teplizumab therapy and suggest that pathways regulating T cell exhaustion may play a role in successful immune interventions for T1D.

Avidity-dependent programming of autoreactive T cells in T1D

Fate determination for autoreactive T cells relies on a series of avidity-dependent interactions during T cell selection, represented by two general types of signals, one based on antigen expression and density during T cell development, and one based on genes that interpret the avidity of TCR interaction to guide developmental outcome. We used proinsulin-specific HLA class II tetramers to purify and determine transcriptional signatures for autoreactive T cells under differential selection in type 1 diabetes (T1D), in which insulin (INS) genotypes consist of protective and susceptible alleles that regulate the level of proinsulin expression in the thymus. Upregulation of steroid nuclear receptor family 4A (NR4A) and early growth response family genes in proinsulin-specific T cells was observed in individuals with susceptible INS-VNTR genotypes, suggesting a mechanism for avidity-dependent fate determination of the T cell repertoire in T1D. The NR4A genes act as translators of TCR signal strength that guide central and peripheral T cell fate decisions through transcriptional modification. We propose that maintenance of an NR4A-guided program in low avidity autoreactive T cells in T1D reflects their prior developmental experience influenced by proinsulin expression, identifying a pathway permissive for autoimmunity.

A harmonized approach to intracellular cytokine staining gating: Results from an international multiconsortia proficiency panel conducted by the Cancer Immunotherapy Consortium (CIC/CRI)

Previous results from two proficiency panels of intracellular cytokine staining (ICS) from the Cancer Immunotherapy Consortium and panels from the National Institute of Allergy and Infectious Disease and the Association for Cancer Immunotherapy highlight the variability across laboratories in reported % CD8+ or % CD4+ cytokine-positive cells. One of the main causes of interassay variability in flow cytometry-based assays is due to differences in gating strategies between laboratories, which may prohibit the generation of robust results within single centers and across institutions. To study how gating strategies affect the variation in reported results, a gating panel was organized where all participants analyzed the same set of Flow Cytometry Standard (FCS) files from a four-color ICS assay using their own gating protocol (Phase I) and a gating protocol drafted by consensus from the organizers of the panel (Phase II). Focusing on analysis removed donor, assay, and instrument variation, enabling us to quantify the variability caused by gating alone. One hundred ten participating laboratories applied 110 different gating approaches. This led to high variability in the reported percentage of cytokine-positive cells and consequently in response detection in Phase I. However, variability was dramatically reduced when all laboratories used the same gating strategy (Phase II). Proximity of the cytokine gate to the negative population most impacted true-positive and false-positive response detection. Recommendations are provided for the (1) placement of the cytokine-positive gate, (2) identification of CD4+ CD8+ double-positive T cells, (3) placement of lymphocyte gate, (4) inclusion of dim cells, (5) gate uniformity, and 6) proper adjustment of the biexponential scaling.

What really happens to tuberculosis patients classified as lost to follow-up in West Yorkshire?

Tuberculosis (TB) patients who do not complete treatment pose a potential public health risk. In West Yorkshire, local clinicians suspected that this risk was overestimated by the national Enhanced Tuberculosis Surveillance system. We audited patients who failed to complete treatment and were categorised as lost-to-follow-up (LTFU) between 2004 and 2008, using a combination of hand searching existing records and obtaining additional information from clinicians. In the study period 2,031 TB cases with reported outcome were notified in West Yorkshire, 23% (n=474) did not complete treatment, and 199 (42%) of those were categorised as LTFU 12 months after notification. Of these 199, 49% (n=98) remained LTFU after the audit, 51% (n=101) were re-classified to the following categories: 24% (n=47) transferred abroad, 16% (n=31) recommenced and completed treatment, 6% (n=13) transferred to another clinic in the United Kingdom (UK), and 5% (n=10) died. These patients therefore no-longer posed a public health risk. Further training for clinicians to improve accuracy of outcome reporting has been initiated. Nationally, the collection of treatment outcome data needs to be strengthened and extending the follow-up for treatment outcome monitoring should be considered.

What really happens to tuberculosis patients classified as lost to follow-up in West Yorkshire?

Tuberculosis (TB) patients who do not complete treatment pose a potential public health risk. In West Yorkshire, local clinicians suspected that this risk was overestimated by the national Enhanced Tuberculosis Surveillance system. We audited patients who failed to complete treatment and were categorised as lost-to-follow-up (LTFU) between 2004 and 2008, using a combination of hand searching existing records and obtaining additional information from clinicians. In the study period 2,031 TB cases with reported outcome were notified in West Yorkshire, 23% (n=474) did not complete treatment, and 199 (42%) of those were categorised as LTFU 12 months after notification. Of these 199, 49% (n=98) remained LTFU after the audit, 51% (n=101) were re-classified to the following categories: 24% (n=47) transferred abroad, 16% (n=31) recommenced and completed treatment, 6% (n=13) transferred to another clinic in the United Kingdom (UK), and 5% (n=10) died. These patients therefore no-longer posed a public health risk. Further training for clinicians to improve accuracy of outcome reporting has been initiated. Nationally, the collection of treatment outcome data needs to be strengthened and extending the follow-up for treatment outcome monitoring should be considered.

Hypoxia triggers a HIF-mediated differentiation of peripheral blood mononuclear cells into osteoclasts

BACKGROUND

The source and mechanisms leading to osteoclast (OC) generation during tooth movement are not clearly understood. We hypothesized that during tooth movement, OC differentiate from peripheral blood mononuclear cells (PBMNC) downstream of the global hypoxia-inducible transcription factor hypoxia-inducible factor (HIF)-1α.

OBJECTIVE

The objective of this study was to demonstrate up-regulation of OC growth factors from osteoblasts (OB) and subsequent conversion of PBMNC into functional OC under hypoxic stress.

MATERIAL AND METHODS

Human primary PBMNC were cocultured with/without OB and subjected to either hypoxia (2.5% O2) or normoxia (21% O2) over 14 days. Levels of HIF, vascular endothelial growth factor (VEGF) and receptor activator for nuclear factor kappa-β ligand (RANKL) were measured. Conversion of PBMNC into OC was measured using resorption and TRAP assays.

RESULTS

Functional OC were only observed in response to hypoxia during coculture of PBMNC and OB and only after up-regulation of HIF, VEGF and RANKL in the hypoxic conditions. YC-1, a HIF inhibitor, reduced OC formation in response to hypoxia.

CONCLUSION

Hypoxia triggers the differentiation of PBMNC into functional OC in the presence of OB in a HIF-dependent manner as would occur during orthodontic loading of the periodontal ligament space.

Immunology of Diabetes Society T-Cell Workshop: HLA class II tetramer-directed epitope validation initiative

BACKGROUND

Islet-antigen-specific CD4+ T cells are known to promote auto-immune destruction in T1D. Measuring T-cell number and function provides an important biomarker. In response to this need, we evaluated responses to proinsulin and GAD epitopes in a multicentre study.

METHODS

A tetramer-based assay was used in five participating centres to measure T-cell reactivities to DR0401-restricted epitopes. Three participating centres concurrently performed ELISPOT or immunoblot assays. Each centre used blind-coded, centrally distributed peptide and tetramer reagents.

RESULTS

All participating centres detected responses to auto-antigens and the positive control antigen, and in some cases cloned the corresponding T cells. However, response rates varied among centres. In total, 74% of patients were positive for at least one islet epitope. The most commonly recognized epitope was GAD270-285. Only a minority of the patients tested by tetramer and ELISPOT were concordant for both assays.

CONCLUSIONS

This study successfully detected GAD and proinsulin responses using centrally distributed blind-coded reagents. Centres with little previous experience using class II tetramer reagents implemented the assay. The variability in response rates observed for different centres suggests technical difficulties and/or heterogeneity within the local patient populations tested. Dual analysis by tetramer and ELISPOT or immunoblot assays was frequently discordant, suggesting that these assays detect distinct cell populations. Future efforts should investigate shared blood samples to evaluate assay reproducibility and longitudinal samples to identify changes in T-cell phenotype that correlate with changes in disease course.

Immunology of Diabetes Society T-Cell Workshop: HLA class I tetramer-directed epitope validation initiative T-Cell Workshop Report-HLA Class I Tetramer Validation Initiative

BACKGROUND

Identification of T-cell reactivity to β-cell antigen epitopes is an important goal for studying pathogenesis and for designing and monitoring of immunotherapeutic interventions in type 1 diabetes (T1D).

METHODS

We performed a multicentre validation of known human leukocyte antigen (HLA) class I CD8+ T-cell epitopes. To this end, peripheral blood T-cell responses were measured in 35 recently (<2 years) diagnosed HLA-A*02:01+ T1D patients using blind-coded HLA-A2 tetramers (TMrs) and pentamers (PMrs), encompassing two epitopes of preproinsulin (PPI; PPIA12-20 and PPIB10-18) and two epitopes of glutamic acid decarboxylase (GAD; GAD114-122 and GAD536-545). We also compared the readout of TMrs and PMrs with a CD8+ T-cell interferon-γ enzyme-linked immunospot assay.

RESULTS

Despite the minute frequencies of autoreactive cells detected by TMrs/PMrs, most (73-77%) T1D patients had responses to one or more of the epitopes used. All four epitopes were recognized by T1D patients, with a prevalence ranging from 5 to 25%. TMrs and PMrs detected more positive responses to the β-cell epitopes than CD8+ T-cell interferon-γ enzyme-linked immunospot. However, concordance between positive responses to TMrs and PMrs was limited.

CONCLUSIONS

Using a multicentre blind-coded setup and three different T-cell assays, we have validated PPI and GAD epitopes as commonly recognized CD8+ T-cell targets in recently diagnosed T1D patients. Both TMrs and PMrs showed higher detection sensitivity than the CD8+ T-cell interferon-γ enzyme-linked immunospot assay. However, there are some important methodological issues that need to be addressed in using these sensitive techniques for detecting low frequency responses.

Effect of acute hyperglycaemia, long-term glycaemic control and insulin on endothelial dysfunction and inflammation in Type 1 diabetic patients with different characteristics

OBJECTIVE

To investigate the possibility of reversing endothelial dysfunction and inflammation by glucose normalization, antioxidants and insulin per se, in different subgroups of Type 1 diabetic patients.

METHODS

Three subgroups of Type 1 diabetic patients were studied: patients within 1 month of diagnosis (subgroup 1); patients with approximately 5 years' disease duration and with glycated haemoglobin (HbA(1c)) <or= 7.0% (subgroup 2) or > 7.0% since diagnosis (subgroup 3). Participants underwent four procedures: 2-h hyperglycaemic clamp followed by: (A) 12 h near-normalization of blood glucose, with the addition of vitamin C during the last 6 h; (B) 12-h vitamin C and near-normalization of blood glucose for the last 6 h; (C) both vitamin C and near-normalization of blood glucose for 12 h; (D) hyperglycaemic-hyperinsulinaemic clamp for 12 h, with the addition of vitamin C during the last 6 h.

RESULTS

After 2 h of hyperglycaemia, markers of endothelial dysfunction, nitrotyrosine, 8-iso prostaglandin F2alpha, soluble intercellular adhesion molecule-1, soluble vascular adhesion molecule-1, interleukin (IL)-6 and IL-18 were increased in all the subgroups. Levels were normalized, at all time points, by treatments A, B and C in the subgroups 1 and 2. In the third subgroup, levels were normalized only by the simultaneous normalization of blood glucose and vitamin C treatment. During treatment D, the levels were improved at 6 h in all the subgroups, but normalized at 12 h only after vitamin C in subgroups 1 and 2, but not in subgroup 3.

CONCLUSIONS

This study suggests that different subgroups of Type 1 diabetic patients react identically to acute hyperglycaemia and insulin, but differently to glucose normalization.

A list of device-specific thresholds for the clinical interpretation of peripheral x-ray absorptiometry examinations

The UK National Osteoporosis Society (NOS) has recently issued new guidelines on the use of peripheral x-ray absorptiometry (pDXA) devices in managing osteoporosis. The NOS guidelines recommend a triage approach in which patients' bone mineral density (BMD) measurements are interpreted using upper and lower thresholds specific to each type of pDXA device. The thresholds are defined so that patients with osteoporosis at the hip or spine are identified with 90% sensitivity and 90% specificity. Patients with a pDXA result below the lower threshold are likely to have osteoporosis at the hip or spine, patients with a result above the upper threshold are unlikely to have osteoporosis, while those between the two thresholds require a hip and spine BMD examination for a definitive diagnosis. This report presents data from a multicenter study to establish the triage thresholds for a range of pDXA devices in use in the UK. The subjects were white female patients aged 55-70 years who met the normal referral criteria for a BMD examination. For each device, at least 70 women with osteoporosis at the hip or spine and 70 women without osteoporosis were enrolled. All women had hip and spine BMD measurements using axial DXA systems that were interpreted using the National Health and Nutrition Examination Survey (NHANES) reference range for the hip and the manufacturers' reference ranges for the spine. Data are presented for five different devices: the Osteometer DTX-200 (forearm BMD), the Schick AccuDEXA (hand BMD), the GE Lunar PIXI (heel BMD), the Alara MetriScan (hand BMD), and the Demetech Calscan (heel BMD). The clinical measurements were supplemented by theoretical modeling to estimate the age dependence of the triage thresholds and the effect of the correlation coefficient between pDXA and axial BMD on the percentage of women referred for an axial BMD examination. In summary, this study provides thresholds for implementing the new NOS guidelines for managing osteoporosis using pDXA devices. The figures reported apply to postmenopausal white women aged 55-70 years who meet the conventional criteria for a BMD examination. The results confirm that the thresholds are specific to each type of pDXA device and that the NOS triage algorithm requires 40% of women to have an axial DXA examination.

Noninvasive quantification of coronary blood flow reserve in humans using myocardial contrast echocardiography

BACKGROUND

We hypothesized that coronary blood flow (CBF) reserve could be quantified noninvasively in humans using myocardial contrast echocardiography (MCE).

METHODS AND RESULTS

Eleven patients with normal epicardial coronary arteries (group I) and 19 with single-vessel coronary stenosis (group II) underwent quantitative coronary angiography, MCE, and CBF velocity measurements at rest and during intravenous adenosine infusion. In group I patients, MCE-derived myocardial blood flow (MBF) velocity reserve (2.4+/-0.08) was similar to CBF velocity reserve using a Doppler flow wire (2.4+/-1.1). Patients with a single risk factor had a significantly higher MBF reserve (3.0+/-0.89) than those with >/=2 risk factors (1.7+/-0.22). In group II patients, significant differences were found in MBF velocity reserve in patients with mild (<50%), moderate (50% to 75%), or severe (>75%) stenoses (2.2+/-0.40, 1.6+/-0.65, and 0.55+/-0.19, respectively; P=0.005). A linear relation was found between flow velocity reserve determined using the 2 methods (r=0.76, P<0.001), and a curvilinear relation was noted between the percent coronary stenosis measured using quantitative coronary angiography and velocity reserve using both methods.

CONCLUSIONS

CBF reserve can be measured in humans using MCE. This method may allow the noninvasive assessment of coronary stenosis severity and the detection of microvascular dysfunction.

Quantification of renal blood flow with contrast-enhanced ultrasound

OBJECTIVES

The goal of this study was to determine the ability of contrast-enhanced ultrasound (CEU) to quantify renal tissue perfusion.

BACKGROUND

The kinetics of tracers used to assess renal perfusion are often complicated by countercurrent exchange, tubular transport or glomerular filtration. We hypothesized that, because gas-filled microbubbles are pure intravascular tracers with a rheology similar to that of red blood cells, CEU could be used to quantify renal tissue perfusion.

METHODS

During a continuous venous infusion of microbubbles (SonoVue), regional renal perfusion was quantified in nine dogs using CEU by destroying microbubbles and measuring their tissue replenishment with intermittent harmonic imaging. Both renal blood volume fraction and microbubble velocity were derived from pulsing-interval versus video-intensity plots. The product of the two was used to calculate renal nutrient blood flow. Renal arterial blood flow was independently measured with ultrasonic flow probes placed directly on the renal artery and was increased using dopamine and decreased by placement of a renal artery stenosis.

RESULTS

An excellent correlation was found between cortical nutrient blood flow using microbubbles and ultrasonic flow probe-derived renal blood flow (r = 0.82, p < 0.001) over a wide range (2.5 fold) of flows.

CONCLUSIONS

Ultrasound examination during microbubble infusion can be used to quantify total organ as well as regional nutrient blood flow to the kidney.

A missense mutation in myosin VIIA prevents aminoglycoside accumulation in early postnatal cochlear hair cells

Myosin VIIA is expressed by sensory hair cells in the inner ear and proximal tubule cells in the kidney, the two primary targets of aminoglycoside antibiotics. Using cochlear cultures prepared from early postnatal Myo7a6J mice with a missense mutation in the head region of the myosin VIIA molecule we show that this myosin is required for aminoglycoside accumulation in cochlear hair cells. Hair cells in homozygous mutant Myo7a6J cochlear cultures have disorganized hair bundles, but are otherwise morphologically normal and transduce. However, and in contrast to hair cells from heterozygous Myo7a6J cultures, the homozygous Myo7a6J hair cells do not accumulate [3H]gentamicin and do not exhibit an ototoxic response on exposure to aminoglycoside. Possible roles for myosin VIIA in the process of aminoglycoside accumulation are discussed.

Identification of eukaryotic parvulin homologues: a new subfamily of peptidylprolyl cis-trans isomerases

We report here the existence of a subfamily of eukaryotic parvulin proteins that have strong sequence homology with E. coli parvulin, but lack the WW domain found in previously described eukarytoic parvulins. We hence term members of this subfamily EPVH (eukaryotic parvulin homologue). We describe the characterisation of hEPVH (human eukaryotic parvulin homologue). Immunogold labelling transmission electron microscopy reveals that hEPVH is preferentially localised in the mitochondrial matrix. The homology of hEPVH with its prokaryotic ancestor supports the hypothesis that this protein may have a mitochondrial function. An essential role in this organelle may explain the need for a high degree of conservation of this protein between distantly related species.

Respiratory insufficiency due to high anterior cervical cord infarction

OBJECTS AND METHODS

Respiratory dysfunction may occur as a result of lesions in the upper cervical spinal cord disturbing the descending pathways subserving automatic and volitional ventilatory control. Four patients are described who presented with acute respiratory insufficiency caused by infarction of the anterior portion of the upper cervical cord due to presumed anterior spinal artery occlusion.

RESULTS

Two patients presented after respiratory arrests; they were ventilated and there was no automatic or volitional respiratory effort. Both had signs of an extensive anterior spinal cord lesion at the C2 level and this was confirmed by MRI. One patient presented with a C4 infarction and required ventilation for three months. Ventilatory recovery was characterised by the development of an automatic respiratory pattern. The fourth patient required ventilation for two months after infarction at the C3 level. On attempted weaning he had prolonged periods of hypoventilation and apnoea during inattention and sleep indicating impairment of automatic respiratory control.

CONCLUSION

Infarction of the spinal cord at high cervical levels may be due to fibrocartilaginous embolism and involvement of the descending respiratory pathways may occur. Extensive lesions at C1/2 cause complete interruption of descending respiratory control leading to apnoea. Partial lesions at C3/4 cause selective interruption of automatic or voluntary pathways and give rise to characteristic respiratory patterns. The prognosis depends on the level and extent of the lesion.

Detection and identification of cannabis by DNA

The unambiguous identification of illicit substances, including Cannabis sativa, is a major concern of law enforcement agencies. Current methods of cannabis identification involve the use of techniques such as HPLC and GC to identify cannabinoids. A method for the identification of cannabis using DNA-specific primers has been developed and is described here. The nucleotide sequences between the trnL and trnF genes in the chloroplast of Cannabis sativa have been determined and Cannabis sativa-specific nucleotide sequences within the intergenic spacer between the trnL 3' exon and trnF gene identified. Primers, made to these sequences, have been tested on a range of different plant extracts but only give a PCR product in the presence of Cannabis sativa. The successful production of a PCR product using these primers identifies the presence of cannabis.

OBITUARY: Rostislav Viktorovich Kazakov: 1941-1997

No abstract

Longitudinal study of soluble adhesion molecules in multiple sclerosis: correlation with gadolinium enhanced magnetic resonance imaging

OBJECTIVE

To assess whether serial serum levels of soluble forms of intercellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1) are useful as surrogate markers of disease activity in multiple sclerosis (MS).

BACKGROUND

Increased levels of sICAM-1 and sVCAM-1 have been described in cross-sectional, but not longitudinal, studies of patients with MS. Although they appear to correlate with clinical and MRI markers of disease activity, their role as potential surrogate markers remains undefined.

METHODS

Serial serum levels of sICAM-1 and sVCAM-1 were measured in patients with MS undergoing monthly gadolinium-enhanced MRI studies of the brain (462 gadolinium-enhanced MRI in 57 patients) and in 12 normal control subjects. Ten patients had primary progressive (PP), 22 relapsing remitting (RR), and 25 secondary progressive (SP) disease.

RESULTS

Levels of sICAM-1 and sVCAM-1 were increased intermittently in patients with all subtypes of MS. Median levels of sICAM-1 were elevated in patients with MS compared with normal controls (normal controls median [interquartile range] = 176[119-209] compared with PP = 502[194-1768], RR = 419[158-481], and SP = 352[196-469] ng/mL; p = 0.04). After excluding patients with PP MS, patients with high sICAM-1 levels had a greater number of gadolinium-enhancing lesions per study (1.9[0.9-4.3]) than patients with normal levels (0.4[0-2.7], p = 0.03), and patients with MRI studies with no gadolinium-enhancing lesions had lower associated sICAM-1 levels (200 ng/mL[85-561]) than patients with only persistent (349 ng/mL[82-615]) or new enhancing lesions (497 ng/mL[108-667], p = 0.03). Patients with RR or SP disease that progressed clinically during the study had a greater number of gadolinium-enhancing lesions per MRI study (3.5[0.4-5.5]) than did patients in whom disease did not progress (1.2 [0.3-2.7], p = 0.03). The patients with progressive disease tended to have higher sICAM-1 levels (469 ng/mL [196-1019]) than patients in whom disease did not progress (353 ng/mL [171-469], p = 0.07). Although MS patients tended to have higher sVCAM-1 levels than did normal controls, this finding was not significant. No correlation could be found between levels of sVCAM-1 and gadolinium enhancement on MRI.

CONCLUSIONS

Patients with MS have elevated levels of sICAM-1, which correlate with gadolinium enhancement on MRI and possibly short-term disease progression. Soluble ICAM-1, and not sVCAM-1, may therefore be suitable as a long-term surrogate marker of disease activity in MS.

CAMPATH-IH in multiple sclerosis

In a pilot study, seven patients with multiple sclerosis were treated with CAMPATH-IH which targets the CD52 antigen present on lymphocytes and monocytes. There was a substantial reduction in disease activity as measured by gadoliunium-enhancing lesions on MRI. Encouraged by this result a further seven patients have been treated with CAMPATH-IH; four also received anti-CD4 antibody. Lymphopaenia developed rapidly and was sustained for at least one year. In 12 patients, the first infusion of antibody was characterised by significant exacerbation or re-awakening of pre-existing symptoms lasting several hours. These clinical effects of antibody treatment correlated with increased levels of circulating cytokines. Peak levels of tumour necrosis factor alpha (TNF alpha) and interferon gamma (IFN gamma) occurred at 2 h whereas the rise in interleukin-6 (IL-6) was significantly delayed and peaked at 4 h after starting antibody treatment. The neurological symptoms could not be attributed directly to pyrexia and were not provoked (in one patient) by an artificial rise in temperature. In the remaining two patients, a single pre-treatment with intravenous methylprednisolone (500 mg) prevented both the transient increase in neurological symptoms and the cytokine release. Our results suggest that soluble immune mediators contribute to symptom production in multiple sclerosis by directly or indirectly blocking conduction through partially demyelinated pathways.

Quantification of MRI lesion load in multiple sclerosis: a comparison of three computer-assisted techniques

Several computer-assisted techniques for measuring multiple sclerosis lesion load on MR images have been developed to provide a quantitative and sensitive means for monitoring disease activity, particularly in the context of treatment trials. We have evaluated three techniques: manual outlining (similar to that of the North American interferon beta-1b trial), semiautomated lesion contouring (local lesion based threshold), and intensity-based thresholding for the whole brain. Contiguous, 5 mm-thick, axial, T2-weighted images of the brain were obtained on a 1.5T MR imager in eight patients with clinically definite multiple sclerosis. Analyses of the scans were performed twice, independently by three operators, using the three different techniques. The coefficient of variation of the measurement techniques was: (a) intrarater precision, 9.0 +/- 5.2 (mean +/- SD) (range 0.4-18.5) for the manual outlining, 2.5 +/- 2.1 (0.1-7.7) for the contour technique, and 7.5 +/- 6.9 (0.2-22.0) for the global threshold technique; (b) interrater precision, 11.0 +/- 5.8 (4.9-21.7) for the manual outlining, 4.5 +/- 1.6 (1.8-6.6) for the contour technique, and 11.4 +/- 4.9 (2.8-19.2) for the global threshold technique (0.0 = perfect precision). The absolute lesion loads measured were very similar using the manual outlining and the contour techniques but were significantly smaller using the global threshold technique. We conclude that the contour technique is a promising tool for use in treatment trials. Further studies are needed to assess sensitivity to changes in lesion load over time.

Encore, a gene required for the regulation of germ line mitosis and oocyte differentiation during Drosophila oogenesis

During Drosophila oogenesis, a stem cell daughter undergoes precisely four rounds of mitosis to generate a cyst of 16 cells interconnected by cytoplasmic bridges. One of the cells becomes the oocyte while the remaining 15 cells differentiate as nurse cells. We hve identified a gene, encore, that is involved both in regulating the number of germline mitoses and in the process of oocyte differentation. Mutations in encore result in exactly one extra round of mitosis in the germline. Genetic and molecular studies indicate that this mitotic defect may be mediated through the gene bag-of-marbles. The isolation and characterization of multiple alleles of encore revealed that they were all temperature sensitive for this phenotype. Mutations in encore also affect the process of oocyte differentiation. Egg chambers are produced in which the oocyte nucleus has undergone endoreplication often resulting in the formation of 16 nurse cells. We argue that these two phenotypes produced by mutations in encore represent two independent requirements for encore during oogenesis.

Mapping of the linear site on the Fas/APO-1 molecule targeted by the prototypic anti-Fas mAb

Fas/APO-1 is a member of the nerve growth factor/tumor necrosis factor (TNF) family of receptors and has been shown to mediate apoptotic cell death upon binding of specific mAb. We report here that the prototypic anti-human Fas mAb (clone CH-11) induces apoptosis by binding to a linear epitope present on the extracellular domain of the Fas/APO-1 protein. Synthetic peptides corresponding to this epitope blocked the apoptotic effect of the antibody in a susceptible Jurkat T cell line. Based upon the similarity between the Fas/APO-1 protein and the recently crystallized soluble TNF receptor type I, we generated a molecular model of Fas/APO-1, Our computer modeling indicates that the antibody binding region forms a hairpin loop on the surface of the Fas/ APO-1 protein. These findings further our understanding of the Fas/APO-1-mediated apoptotic signal and may provide a useful tool in future investigations of programmed cell death.

High resolution magnetic resonance imaging of the anterior visual pathway in patients with optic neuropathies using fast spin echo and phased array local coils

High resolution MRI of the anterior visual pathways was evaluated using frequency selective fat suppressed fast spin echo (FSE) sequences in conjunction with phased array local coils in patients with optic neuropathies. Fifteen normal controls and 57 patients were examined. Coronal T2 weighted fat suppressed FSE images were obtained in 11 minutes with an in plane resolution of 0.39 x 0.39 mm. The optic nerve and its sheath containing CSF were clearly differentiated. Central retinal vessels were often visible. In demyelinating optic neuritis and in anterior ischaemic optic neuropathy high signal within the nerve was readily delineated. Meningiomas and gliomas involving the optic nerve were precisely visualised both in the orbit and intracranially. Extrinsic compression of the optic nerves was readily visualised in carotid artery ectasia and dysthyroid eye disease. Enlarged subarachnoid spaces around the optic nerves were demonstrated in benign intracranial hypertension. High resolution MRI of the anterior visual pathway represents an advance in the diagnosis and management of patients presenting with optic neuropathy.