Clinico-mycological and therapeutic updates on tinea corporis/cruris in the era of Trichophyton indotineae

Trichophyton indotineae (TI) has emerged as a novel dermatophyte species causing treatment recalcitrant skin infections. While the earliest reports came from India, TI has now spread to many parts of the world and is rapidly becoming a global health concern. Accurate identification of TI requires elaborate mycological investigations not in the domain of routine microbiology laboratories. Extensive, non-inflammatory and atypical presentations are commonly seen with this novel species. TI shows an alarmingly high rate of mutations in the squalene epoxidase gene leading to lowered invitro susceptibility to terbinafine. This has also translated into a lowered clinical response and requirement of a higher dose and much longer durations of treatment with the drug. Although the species remains largely susceptible to Itraconazole (ITZ), prolonged treatment durations are required to achieve cure with ITZ as well. Fluconazole and griseofulvin do not have satisfactory invitro or clinical activity. Apart from requirement of prolonged treatment durations, relapse post successful treatment is a distressing and yet unexplained consequence of this "species-shift". Use of third generation azoles and combinations of systemic antifungals is unwarranted as both have not demonstrated clear superiority over ITZ given alone, and the former is an important class of drugs for invasive mycoses.

Consolidative Radiotherapy for Residual PET-Avid Disease on Day +30 Post CAR T-Cell Therapy in Non-Hodgkin Lymphoma

PURPOSE/OBJECTIVE(S)

Up to30% of non-Hodgkin lymphoma (NHL) patients achieve a partial response (PR) to anti-CD19 Chimeric Antigen Receptor T-cell Therapy (CART) on day +30. Most PR patients relapse and only 30% achieve spontaneous complete response (CR) without additional therapies. This study is the first to report on the role of consolidative radiotherapy (cRT) for PR PET-avid disease on day +30 post-CART in NHL.

MATERIALS/METHODS

Aretrospective review across 3 institutions from 2018 to 2022 identified 60 patients with B-cell NHL who received CART and achieved PR (Deauville 4-5) with <5 PET-avid disease sites on day +30. Progression-free survival (PFS) was defined from CART infusion to any disease progression. Overall survival (OS) was defined from CART infusion to death. Local relapse-free survival (LRFS), calculated based on the total number of PR sites, was defined from CART infusion to local relapse (LR) in the PR site identified on day +30. cRT was defined as comprehensive (compRT) - treated all PR PET-avid sites - or focal (focRT).

RESULTS

Followingday +30 PET scan, 45 PR patients were observed and 15 received cRT. Only one patient received consolidative systemic therapy and belonged to the cRT group. Prior to CART, bridging RT was given to 13 patients (9 in observation group and 4 in cRT group). There were no significant differences in the pre-CART and day +30 baseline characteristics, including the median size and SUVmax of the PR sites, between the two groups. However, the median number of PR sites on day +30 was higher in the cRT group (2 [range 1-3] vs 1 [range 1-3], p = 0.003). The median equivalent 2 Gy dose was 39.1 (Interquartile range 36.8-41) Gy, and the most common cRT regimen was 37.5 Gy in 15 fractions. The median follow-up was 21 months. Among the observed patients, 15 (33%) achieved spontaneous CR, and 27 (60%) experienced disease progression with all relapses involving the initial PR sites. Among patients who received cRT, 10 (67%) achieved CR, and 3 (20%) had disease progression with no relapses in the radiated PR sites. None of the 10 cRT patients achieving CR relapsed or required subsequent therapies. The 2-year PFS was 80% and 37% (p = 0.012) and the 2-year OS was 78% and 43% (p = 0.12) in the cRT and observation groups, respectively. Patients consolidated with compRT (n = 12) had superior 2-year PFS (92% vs 37%, p = 0.003) and 2-year OS (86% vs 43%, p = 0.048) compared to observed or focRT patients (n = 48). There were no grade 3+ RT-related toxicities. A total of 90 PR sites were identified; 64 were observed and 26 received cRT. Fourteen (22%) observed PR sites achieved spontaneous sustained CR and 42 (66%) experienced LR. Twenty-four (92%) PR sites consolidated with cRT achieved sustained CR and none experienced LR. The 2-year LRFS was 100% in the cRT sites and 31% in the observed sites (p<0.001).

CONCLUSION

NHL patients who achieve PR by PET to CART are at high risk of local progression. cRT for residual PET-avid disease on day +30 post-CART appears to alter the pattern of relapse and improve LRFS and PFS.

Variations in atrial fibrillation ablation utilization and reimbursement among medicare beneficiaries: an observational study from 2013 to 2019

Background

Atrial fibrillation (AF) pulmonary vein isolation ablation has been utilized increasingly yet variably in the USA.

Purpose

To identify variations in AF ablation utilization and reimbursement among Medicare beneficiaries (MB).

Methodology

We used a 100% sample of MB who underwent AF ablation from 2013 to 2019. We stratified data geographically (Northeast, South, West, and Midwest), identified the mean AF prevalence and the number of AF ablations per 100,000 MB, and examined the correlation between AF prevalence and ablation. We also examined the number of cardiologists performing AF ablation per 100,000 MB and the average number of AF ablation per individual cardiologist (ablation/cardiologist), as well as average submitted charge (ASC) for AF ablation. Additionally, we stratified data per urban versus rural areas as well as the gender of performing cardiologists and examined ablation/cardiologist and the ASC.

Results

Geographic analysis: The mean AF prevalence, the rates AF ablation per 100,000 MB, the number of cardiologists per 100,000 MB, and ablation/cardiologist have shown a steady increase in all regions across years. In all years, the mean AF prevalence was significantly different among regions with the highest prevalence in the Northeast and the lowest in the West (all P&lt;0.001), however, there was no significant difference in the rates of AF ablation per 100,000 MB (all P≥0.056). There was significant correlation between AF prevalence and ablation only in the Midwest and the West, with 46.4% and 43.4% positive correlation respectively (P≤0.0001). The number of cardiologists performing AF ablation per 100,000 MB was not significantly different among regions in all years (All P≥0.48), however, ablation/cardiologist was significantly higher in the West and the South compared to the Northeast and the Midwest (All P&lt;0.0001). On the contrary, the ASC has shown steady decrease in all regions. The ASC was significantly different among regions in all year (all P≤0.003) with higher ASC in the Midwest and the Northeast compared to the south and the West.

Urban vs rural analysis: Ablation/cardiologist was not significantly different between urban and rural areas in all years (all P≥0.068) except in 2013 when it was significantly higher in urban areas (P=0.004). The ASC was significantly higher in rural areas only in 2015 and 2019 (P=0.037 and P=0.029 respectively) however, there was no significant difference in the rest of the years (P≥0.07).

Gender analysis: Ablation/cardiologist was not significantly different between male and female cardiologists in all years (P≥0.056) except in 2017 when the average was significantly higher per male cardiologists (P=0.007). The ASC was not significantly different in all years (P≥0.362).

Conclusion

There are variations in AF ablation utilization and reimbursement among MB in the USA according to geographic, urban and rural regions, and the gender of performing cardiologists.

Funding Acknowledgement

Type of funding sources: None.

201 Compliance to New BOAST's Guidelines for Paediatric Supracondylar Fractures in the Middle of COVID Pandemic

Aim

Amid COVID pressures, standards of surgical practices need constant reviewing to maintain patient safety and streamline care pathways. Newly published BOAST (British Orthopaedic Association Standards for Trauma and Orthopaedics) guidelines for paediatric supracondylar fractures became a benchmark against which a restructured DGH trauma unit's performance can be appraised.

Method

Theatre records were analysed between April-2020 and September-2020. Data were collected to reveal time to theatre, operative techniques, documentations of ulnar nerve protection, complications, follow-up plans, time to first post-op radiograph and to wire removal.

Results

90% of patients underwent operations within 24–48 hour. Although there was no incidence of iatrogenic nerve injury, documentation of ulnar nerve protection was not identified in 45% of crossed wire fixations. Wire size was not mentioned in 14%. 33% did not have first follow-up with radiograph within 4–10 days, and 43% of patients did not have the wires removed till 4 weeks post op.

Conclusion

This re-audit highlights the need to improve in documentation for ulnar nerve protection and to identify the delays in follow-up appointments. Although BOAST no longer recommends a fixed timeframe for follow-up plan, first radiograph within 4–10 days and wire removal within 4 weeks are still reasonable locally.

Stimulation of a subset of natural killer T cells by CD103+ DC is required for GM-CSF and protection from pneumococcal infection

Innate-like T cells, including invariant natural killer T cells, mucosal-associated invariant T cells, and γδ T cells, are present in various barrier tissues, including the lung, where they carry out protective responses during infections. Here, we investigate their roles during pulmonary pneumococcal infection. Following infection, innate-like T cells rapidly increase in lung tissue, in part through recruitment, but T cell antigen receptor activation and cytokine production occur mostly in interleukin-17-producing NKT17 and γδ T cells. NKT17 cells are preferentially located within lung tissue prior to infection, as are CD103⁺ dendritic cells, which are important both for antigen presentation to NKT17 cells and γδ T cell activation. Whereas interleukin-17-producing γδ T cells are numerous, granulocyte-macrophage colony-stimulating factor is exclusive to NKT17 cells and is required for optimal protection. These studies demonstrate how particular cellular interactions and responses of functional subsets of innate-like T cells contribute to protection from pathogenic lung infection.

'Mind if I record this?' Patients making audio-visual recordings of consultations: a survey of surgeons' experiences

INTRODUCTION

Audio-visual recordings made by patients of their clinical encounters are increasingly common. This may be done with or without their doctors' knowledge or consent and is considered admissible legal evidence. Many surgeons may feel uncomfortable with being recorded and lack knowledge regarding the legal implications. The aim of this study was to gauge how surgeons react to being recorded, and what specific medico-legal insight they have regarding these matters.

METHODS

In total, 150 surveys were distributed to surgeons in two hospitals in South Wales by email, Survey Monkey and paper copy between 28 October 2019 and 9 March 2020. The survey was anonymous and recorded level of training, as well as four simple questions regarding how surgeons may react to being recorded and what they felt their legal rights were.

RESULTS

There were 91 respondents: 28 consultants, 36 registrars and 27 junior surgical trainees. Of the respondents, 56% were uncomfortable with being recorded and 23% would stop a consultation if their patient insisted on recording it. These issues were most marked for junior surgical trainees. Sixty-two per cent of respondents were unaware of their legal rights and 21% believed they were legally able to refuse to continue a consultation. This belief was particularly marked among consultants.

CONCLUSION

Many surgeons are uncomfortable with being recorded and lack knowledge regarding their medico-legal standing. Education and guidance from the Royal Colleges would help address this issue and avoid misunderstanding when surgeons are faced with these potentially difficult scenarios.

Symphytum officinale augments osteogenesis in human bone marrow-derived mesenchymal stem cells in vitro as they differentiate into osteoblasts

ETHNOPHARMACOLOGICAL RELEVANCE

Mesenchymal stem cells (MSCs) are multipotent stem cells possessing regenerative potential. Symphytum officinale (SO) is a medicinal plant and in homoeopathic literature, believed to accelerate bone healing.

AIM OF THE STUDY

This study aimed to determine if homoeopathic doses of SO could augment osteogenesis in MSCs as they differentiate into osteoblasts in vitro.

MATERIALS AND METHODS

Bone marrow samples were obtained from patients who underwent bone grafting procedures (n = 15). MSCs were isolated, expanded and characterized by flow cytometry (CD90, CD105). Cytotoxicity of SO was evaluated by MTT assay. Osteogenic differentiation was induced in MSCs with β-glycerophosphate, ascorbic acid and dexamethasone over 2 weeks. Different homoeopathic doses of SO (MT, 3C, 6C, 12C and 30C) were added to the basic differentiation medium (BDM) and efficiency of MSCs differentiating into osteoblasts were measured by evaluating expression of Osteocalcin using flow cytometry, and alkaline phosphatase activity using ELISA. Gene expression analyses for osteoblast markers (Runx-2, Osteopontin and Osteocalcin) were evaluated in differentiated osteoblasts using qPCR.

RESULTS

Flow cytometry (CD90, CD105) detected MSCs isolated from bone marrow (93-98%). MTT assay showed that the selected doses of SO did not induce any cytotoxicity in MSCs (24 hours). The efficiency of osteogenic differentiation (2 weeks) for different doses of Symphytum officinale was determined by flow cytometry (n = 10) for osteoblast marker, Osteocalcin, and most doses of Symphytum officinale enhanced osteogenesis. Interestingly, gene expression analysis for Runx-2 (n = 10), Osteopontin (n = 10), Osteocalcin (n = 10) and alkaline phosphatase activity (n = 8) also showed increased osteogenesis with the addition of Symphytum officinale to BDM, specially mother tincture.

CONCLUSIONS

Our findings suggest that homoeopathic dose (specially mother tincture) of Symphytum officinale has the potential to enhance osteogenesis.

Development of Asthma in Inner-City Children: Possible Roles of MAIT Cells and Variation in the Home Environment

Humans have populations of innate-like T lymphocytes with an invariant TCR α-chain that recognize nonpeptide Ags, including invariant NKT (iNKT) cells and mucosal-associated invariant T (MAIT) cells. iNKT cell involvement in human asthma is controversial, whereas there has been little analysis of MAIT cells. Using peripheral blood cells from 110 participants from the Urban Environment and Childhood Asthma (URECA) birth cohort study, these cells were analyzed for number and function. We determined whether iNKT cell or MAIT cell frequency at 1 y is correlated with the cytokine polarization of mainstream CD4+ T cells and/or the development of asthma by age 7 y. Dust samples from 300 houses were tested for iNKT cell antigenic activity. Our results show that a higher MAIT cell frequency at 1 y of age was associated with a decreased risk of asthma by age 7 y. The frequency of MAIT cells was associated with increased production of IFN-γ by activated CD4+ T cells from the URECA cohort. iNKT cell antigenic activity in bedroom dust samples was associated with higher endotoxin concentration and also with reduced risk of asthma. In conclusion, MAIT cell frequency at 1 y may reflect the tendency of the immune system toward Th1 responses and is associated with protection from asthma. Additionally, iNKT cell antigenic activity may be a marker of houses with increased microbial exposures and therefore also with protection from asthma.

Management of neglected ACL avulsion fractures: a case series and systematic review

INTRODUCTION

Neglected tibial eminence avulsion fractures of the anterior cruciate ligament (ACL) are uncommonly seen in modern times, but are fairly common due to a missed diagnosis/mismanagement in developing countries.

OBJECTIVES

To determine the outcomes after open reduction and internal fixation of late presenting ACL avulsion fractures, and to review the literature for similar cases, in an attempt to evaluate the ideal surgical management in this unique scenario.

STUDY DESIGN

Retrospective observational study and systematic review MATERIALS: The study included 10 male and 2 female cases (mean age 29.9 years). Patients were assessed for the pre-operative knee range-of-motion (ROM), flexion deformity and stability; functional assessment was conducted using the Lysholm scale, both pre and post-operatively. Open reduction and internal fixation with two partially threaded screws (via a mini anterior approach) was performed in all 12 cases. All patients were clinically followed up for a minimum duration of 12 months. We searched PubMed, Embase and Cochrane databases from the period of inception to January 15, 2017 for similar case series/reports involving management of chronic/neglected ACL avulsion fractures and systematically reviewed these studies following standard PRISMA guidelines.

RESULTS

The median duration of presentation after injury was 12 months (range 3 to 312 months; mean 45.3 months). The mean follow-up duration was 24.1 months (range 12-48 months). All patients achieved normal knee extension except one patient who had a residual 5° flexion contracture. On physical examination, Lachman and pivot-shift tests were negative in all but 1 patient. No case required ACL reconstruction, and the fractures united radiologically within 12 weeks; all patients regained former activity levels.

DISCUSSION

Eleven published studies, mainly case reports, reported on the management of chronic/neglected ACL avulsion fractures. Arthroscopic suture/wire fixation, arthroscopic debridement of avulsed fragment and open reduction, internal fixation (ORIF) with screws are the described techniques for this uncommon entity. However, anatomic reduction of ACL avulsion fractures is difficult arthroscopically as crater depth assessment and repositioning of the avulsed fragment become a problem; the avulsed fragment may also hypertrophy, and some contractures in ACL may develop. A mini-open procedure does not add to the morbidity, overcomes reduction obstacles and allows easy fixation with screws, and can be done even in centers that do not have arthroscopic experience. The key point is accurate reduction and rigid fixation, ensuring no impingement on full extension CONCLUSIONS: Mini-open fixation allows accurate, anatomic reduction and stable fixation with screws, and should be the preferred method of fixation for late presenting ACL avulsion fractures; embedding the fragment deep into the crater or size reduction are key to preventing extension deficits.

Allergy and asthma in inner-city children: possible roles of MAIT cells and variation in the home environment

Humans have two populations of innate-like T lymphocytes with an invariant T cell antigen receptor (TCR) a chain: invariant natural killer T (iNKT) cells and mucosal associated invariant T (MAIT) cells. iNKT cell involvement in human asthma has been suggested, but is controversial, while there has been little analysis of MAIT cells. Using peripheral blood cells from the urban environment and childhood asthma (URECA) birth cohort study, we carried out a comprehensive investigation to determine if iNKT cell frequency or MAIT cell frequency early in life is correlated with the cytokine polarization of mainstream CD4+T cells and/or the development of asthma by age seven. We also determined if iNKT cell antigenic activity in house dust samples was associated with environmental endotoxin or clinical outcomes including aeroallergen sensitization and recurrent wheeze at 3 and asthma at age 7. We also analyzed the correlation between cytokines released by activated iNKT and MAIT cells and various clinical outcomes. Our results shows that the frequency of MAIT cells was associated with increased production of IFNg by activated CD4+ T cells from children that did not go on to develop asthma. Moreover, an increased MAIT cell frequency early in life was associated with a decreased risk of asthma by age seven. In contrast, iNKT cell frequency early in life was not correlated with the development of asthma or allergic sensitization. iNKT cell antigen content in house dust varied greatly, and increased antigen was associated not only with endotoxin levels in the surroundings but also with protection from asthma. Together, these data suggest that MAIT cell frequency and iNKT cell antigen content at one year correlates with protection from asthma development.

A whole genome mouse siRNA screen to identify novel genes involved in lipid antigen presentation

Although most T lymphocytes recognize peptides presented by major histocompatibility complex (MHC)-encoded class I and class II molecules, there also are significant populations of T cells that recognize nonpeptide antigens. Prominent among these T lymphocytes are the type I or invariant natural killer T cells (iNKT cells). These T lymphocytes recognize lipids presented by CD1d, a nonpolymorphic, class I-like, antigen-presenting molecule. We have carried out a whole genome siRNA screen in a macrophage cell line for genes that affect the presentation of a potent glycosphingolipid antigen, GalGal Cer, to iNKT cells. In order to stimulate iNKT cells, this antigen requires internalization and lysosomal carbohydrate antigen processing to remove the terminal galactose. After several rounds of validation, functional classification and gene expression analysis, we have identified genes that lead to altered antigen presentation in macrophages. A majority of the identified genes do not perturb surface CD1d expression, but we can demonstrate they effect the formation of surface CD1d complexes with the stimulating glycolipid. Members of the HOPS and ESCRT complexes have been identified to play an important role in Cd1d dependent antigen presentation. Interestingly, our data show that ABCC1 and several other ABC family transporters are involved in lipid antigen presentation by CD1d. CD1d and MHC-II antigen presentation pathways both depends on antigen loading in the lysosome, therefore we also analyzed the role of these genes in MHC-II antigen presentation. Although the majority of genes identified doesn’t affect MHC-II antigen presentation, there are a few molecules that affect both antigen presentation pathways.

Abstract P5-03-10: Development of a novel HER2 testing strategy, using image-based cell-sorting to isolate pure cell populations from FFPE upstream of FISH

Fluorescent in Situ Hybridization (FISH) guidelines defined by American Society of Clinical Oncology (ASCO) and the College of American Pathologists for determining HER2 status are set to improve accuracy and usefulness as a diagnostic marker in breast cancer. Despite these guidelines, many factors can influence HER2 testing results such as sample preparation, assay-conditions and interpretation of test results due to heterogeneous breast cancer samples. In this multi-site study, sample preparation was carried out using the DEPArray™ to recover pure tumor cell populations from formalin-fixed, paraffin-embedded (FFPE) breast tumor samples. We then compared HER2/CEP17 ratios obtained from the DEPArray™ processed samples from each laboratory to routine FISH on tissue sections.

Methods: Eight breast FFPE tumor tissue biopsies were obtained from commercial tissue banks. From the paraffin tissue blocks, four consecutive tissue curls (each 50 microns thick) were prepared. One curl from each of the 8 patient samples was distributed to four different laboratories for analysis following DEPArray™ based sample preparation. After an initial disassociation of each curl into a single-cell suspension, intact cells were sorted and then recovered based on cytokeratin/ vimentin/DAPI staining using the DEPArray™. Cytokeratin+/Vimentin-/DAPI+ tumor (~250) and Cytokeratin-/Vimentin+/DAPI+ stromal (~250) recovered cells were then deposited onto glass slides prior to standard dual-color HER2/CEP17 FISH analysis for comparison to conventional HER2 FISH result.

Results: Serially sectioned breast tumors from 8 negative/positive cases: 7 infiltrating ductal carcinoma (IDC) and 1 metastatic carcinoma were studied. All four sites demonstrated 100% concordance between FISH results compared to the conventional HER2 FISH result. Overall, &gt;60% of DEPArray™ isolated cells were recovered from FFPE samples that ranged from 1- 15 years of age and reported to contain 60% to 80% tumor content. The use of pure sorted cells permitted the accurate determination of HER2 amplification status in only the tumor cells while the stromal cells consistently yielded a more normalized ratio of HER2 to centromere 17.

Conclusion: The preliminary results of this multi-site study demonstrate that use of DEPArray™ for sorted pure populations is reproducible as well as reliable method for subsequent analysis of HER2 by FISH on FFPE derived tumor cells. Given that traditional FFPE-based HER2 FISH results may be influenced by the tissue sectioning procedure, tissue heterogeneity and/or the scattering of few HER2 amplified tumor cells among normal stromal cells. The DEPArray™ allows analysis of immunofluorescence images and DNA content to isolate and recover pure and intact cell populations. This isolation of pure cell populations prior to FISH analysis is attractive for achieving precise determination of HER2 status on equivocal cases. A more formal analytical validation of this approach through CLIA is currently underway.

Citation Format: Gerber A, Konig L, Millner L, Strotoman L, Khurana A, Kasimir-Bauer S, Moore MW, Cotter PD, Bischoff F. Development of a novel HER2 testing strategy, using image-based cell-sorting to isolate pure cell populations from FFPE upstream of FISH [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-03-10.

Dealing with sub-trochanteric fracture in a child with osteopetrosis : A case report

Osteopetrosis is a rare hereditary condition which may have autosomal recessive or autosomal dominant inheritance. Patients tend to present most commonly with fractures but involvement of cranial nerves and hematopoetic system is not uncommon. Patients with infantile and intermediate type tend to present more often with problems other than orthopaedic problems. While diagnosis can be made on the basis of radiographs, management needs to be customized for every patient. Non operative and operative management both have their advantages and disadvantages. We are here reporting a case of sub-trochanteric fracture in an eight-year-old child which was managed successfully with a dynamic hip screw (DHS). Surgery could be performed successfully by taking precautions during reduction, drilling and screw placement. At the latest follow up, which was after one and half years of surgery, the fracture had united well and the child faced no limitations of activities. Thus, open reduction and fixation with DHS can be considered as an effective management modality for pediatric sub-trochanteric fractures in osteopetrosis.

Effect of narrow band ultraviolet B phototherapy on T helper 17 cell specific cytokines (interleukins-17, 22 and 23) in psoriasis vulgaris

BACKGROUND

Psoriasis is mediated by a T helper 17 (Th17) cell inflammatory process. This study describes the changes in serum levels of IL-17, 22 and 23 in patients of psoriasis vulgaris treated with narrow band ultraviolet B (NBUVB).

METHODS

The serum levels of IL-17, 22 and 23 were compared with a control group (n = 30) before and after NBUVB. In addition, post-NBUVB levels were compared with healthy controls. Psoriasis Area Severity Score (PASI) and Body Surface Area scoring were used to evaluate severity of disease.

RESULTS

When compared with the non-psoriasis control group, IL-17, 22 and 23 were higher in psoriasis patients (p < 0.05, p < 0.001, p < 0.001, respectively). The serum levels of all three interleukins strongly correlated with severity of disease. Although IL-17, 22 and 23 decreased after NBUVB, decline in IL-17 was not significant after phototherapy as compared to controls (p = 0.634). IL-22 and 23 continued to remain elevated post-phototherapy when compared with control group (p < 0.05, p < 0.0001, respectively).

CONCLUSIONS

The serum levels of IL-17, 22 and 23 decrease after phototherapy in psoriasis. Post-phototherapy only the IL-17 levels decrease to that of non-psoriasis controls. Our study supports the role of T helper 17 cell specific cytokines in psoriasis and a possible mechanism of action of NBUVB via inhibition of these cytokines.

CD1d-restricted peripheral T cell lymphoma in mice and humans

Peripheral T cell lymphomas (PTCLs) are a heterogeneous entity of neoplasms with poor prognosis, lack of effective therapies, and a largely unknown pathophysiology. Identifying the mechanism of lymphomagenesis and cell-of-origin from which PTCLs arise is crucial for the development of efficient treatment strategies. In addition to the well-described thymic lymphomas, we found that p53-deficient mice also developed mature PTCLs that did not originate from conventional T cells but from CD1d-restricted NKT cells. PTCLs showed phenotypic features of activated NKT cells, such as PD-1 up-regulation and loss of NK1.1 expression. Injections of heat-killed Streptococcus pneumonia, known to express glycolipid antigens activating NKT cells, increased the incidence of these PTCLs, whereas Escherichia coli injection did not. Gene expression profile analyses indicated a significant down-regulation of genes in the TCR signaling pathway in PTCL, a common feature of chronically activated T cells. Targeting TCR signaling pathway in lymphoma cells, either with cyclosporine A or anti-CD1d blocking antibody, prolonged mice survival. Importantly, we identified human CD1d-restricted lymphoma cells within Vδ1 TCR-expressing PTCL. These results define a new subtype of PTCL and pave the way for the development of blocking anti-CD1d antibody for therapeutic purposes in humans.

A Novel Glycolipid Antigen for NKT Cells That Preferentially Induces IFN-γ Production

In this article, we characterize a novel Ag for invariant NKT (iNKT) cells capable of producing an especially robust Th1 response. This glycosphingolipid, DB06-1, is similar in chemical structure to the well-studied α-galactosylceramide (αGalCer), with the only change being a single atom: the substitution of a carbonyl oxygen with a sulfur atom. Although DB06-1 is not a more effective Ag in vitro, the small chemical change has a marked impact on the ability of this lipid Ag to stimulate iNKT cells in vivo, with increased IFN-γ production at 24 h compared with αGalCer, increased IL-12, and increased activation of NK cells to produce IFN-γ. These changes are correlated with an enhanced ability of DB06-1 to load in the CD1d molecules expressed by dendritic cells in vivo. Moreover, structural studies suggest a tighter fit into the CD1d binding groove by DB06-1 compared with αGalCer. Surprisingly, when iNKT cells previously exposed to DB06-1 are restimulated weeks later, they have greatly increased IL-10 production. Therefore, our data are consistent with a model whereby augmented and or prolonged presentation of a glycolipid Ag leads to increased activation of NK cells and a Th1-skewed immune response, which may result, in part, from enhanced loading into CD1d. Furthermore, our data suggest that strong antigenic stimulation in vivo may lead to the expansion of IL-10-producing iNKT cells, which could counteract the benefits of increased early IFN-γ production.

Lipid and Carbohydrate Modifications of α-Galactosylceramide Differently Influence Mouse and Human Type I Natural Killer T Cell Activation

The ability of different glycosphingolipids (GSLs) to activate type I natural killer T cells (NKT cells) has been known for 2 decades. The possible therapeutic use of these GSLs has been studied in many ways; however, studies are needed in which the efficacy of promising GSLs is compared under identical conditions. Here, we compare five unique GSLs structurally derived from α-galactosylceramide. We employed biophysical and biological assays, as well as x-ray crystallography to study the impact of the chemical modifications of the antigen on type I NKT cell activation. Although all glycolipids are bound by the T cell receptor of type I NKT cells in real time binding assays with high affinity, only a few activate type I NKT cells in in vivo or in vitro experiments. The differences in biological responses are likely a result of different pharmacokinetic properties of each lipid, which carry modifications at different parts of the molecule. Our results indicate a need to perform a variety of assays to ascertain the therapeutic potential of type I NKT cell GSL activators.

Synthesis of a 2"-deoxy-β-GalCer

Structural studies of ternary complexes of CD1d/glycosyl ceramides/iNKT cells and CD1d/sulfatide/sulfatide reactive Type II NKT cells have shown how the polar moieties on the glycolipids interact with both the antigen presenting protein (CD1d) and the T cell receptors. However, these structures alone do not reveal the relative importance of these interactions. This study focuses on the synthesis of the previously unknown 2"-deoxy-β-galactosyl ceramide 2. This glycolipid is also evaluated for its ability to stimulate iNKT cells and sulfatide-reactive Type II NKT cells.

Tuberculosis lymphadenitis in a well managed case of sarcoidosis

Differentiation between tuberculosis (TB) and sarcoidoisis is sometimes extremely difficult. Sequential occurrence of sarcoidosis and TB in the same patient is uncommon. We present the case of a young man, with a proven diagnosis of sarcoidosis who later developed TB after completion of treatment for sarcoidosis. A 32-year-old male patient presented with low-grade fever since two months. Physical examination revealed cervical lymphadenopathy. Initial fine needle aspiration cytology (FNAC) of the cervical lymph node was suggestive of granulomatous inflammation; the chest radiograph was normal. Repeat FNAC from the same lymph node was suggestive of reactive lymphoid hyperplasia. The patient was treated with antibiotics and followed-up. He again presented with persistence of fever and lymphadenopathy and blurring of vision. Ophthalmological examination revealed uveitis, possibly due to a granulomatous cause. His repeat Mantoux test again was non-reactive; serum angiotensin converting enzyme (ACE) levels were raised. This time an excision biopsy of the lymph node was done which revealed discrete, non-caseating, reticulin rich granulomatous inflammation suggestive of sarcoidosis. The patient was treated with oral prednisolone and imporved symptomatically. Subsequently, nearly nine months after completion of corticosteroid treatment, he presented with low-grade, intermittent fever and a lymph node enlargement in the right parotid region. FNAC from this lymph node showed caseating granulomatous inflammation and the stain for acid-fast bacilli was positive. He was treated with Category I DOTS under the Revised National Tuberculosis Control Programme and improved significantly. The present case highlights the need for further research into the aetiology of TB and sarcoidosis.

Intracranial hypotension with a sixth cranial nerve palsy subsequent to massive thoracic CSF hygroma: a rare complication of thoracic disc excision

BACKGROUND

Thoracic cerebrospinal fluid (CSF) hygroma is a rare and potentially devastating complication of the anterior thoracic approach to the spine. We present two cases in which this complication resulted in acute cranial nerve palsy and discuss the pathoanatomy and management options in this scenario.

CASE REPORTS

Two male patients presented to our department with neurological deterioration due to a giant herniated thoracic disc. The extruded disc fragment was noted pre-operatively to be calcified in both patients. A durotomy was performed at primary disc prolapse resection in the first patient, whereas an incidental durotomy during the procedure caused complication in the second patient. These were repaired primarily or sealed with Tachosil(®). Both patients re-presented with acute diplopia. Imaging of both patients confirmed a massive thoracic cerebrospinal fluid hygroma and evidence of intracranial changes in keeping with intracranial hypotension, but no obvious brain stem shift. The hemithorax was re-explored and the dural repair was revised. The first patient made a full recovery within 3 months. The second patient was managed conservatively and took 5 months for improvement in his ophthalmic symptoms.

CONCLUSIONS

The risk of CSF leakage post-dural repair into the thoracic cavity is raised due to local factors related to the chest cavity. Dural repairs can fail in the presence of an acute increase in CSF pressure, for example whilst sneezing. Intracranial hypotension can result in subsequent hygroma and possibly haematoma formation. The resultant cranial nerve palsy may be managed expectantly except in the setting of symptomatic subdural haematoma or compressive pneumocephaly.

Accuracy of the revised Tokuhashi score in predicting survival in patients with metastatic spinal cord compression (MSCC)

PURPOSE

The revised Tokuhashi score has been widely used to evaluate indications for surgery and predict survival in patients with metastatic spinal disease. Our aim was to analyse the actual survival time of patients treated for metastatic spinal cord compression (MSCC) in comparison with the predicted survival based on the revised Tokuhashi score. This would thereby allow us to determine the overall predictive value of this scoring system.

METHODS

This study was a semi-prospective clinical study of all patients with MSCC presenting to our unit over 8 years-data from October 2003 to December 2009 were collected retrospectively and from December 2009, all data collected prospectively to October 2011. Patients were divided into three groups--Group 1 (Tokuhashi score 0-8, n = 84), Group 2 (Tokuhashi score 9-11, n = 83) and Group 3 (Tokuhashi score 12-15, n = 34). Data collected included demographic data, primary tumour histology, surgery type and complications, neurological outcome (Frankel grade) and survival.

RESULTS

A total of 233 patients with MSCC were managed surgically in our unit during this time. Out of these complete data were available on 201 patients for analysis. Mean age of patients was 61 years (range 18-86; 127 M, 74 F). The primary tumour type was Breast (n = 29, 15 %), Haematological (n = 28, 14 %), Renal (n = 26, 13 %), Prostate (n = 26, 13 %), Lung (n = 23, 11 %), Gastro-intestinal (n = 11, 5 %), Sarcoma (n = 9, 4 %) and others (n = 49, 24 %). All patients included in the study had surgical intervention in the form of decompression and stabilisation. Posterior decompression and stabilisation was performed in 171 patients (with vertebrectomy in 31), combined anterior and posterior approaches were used in 18 patients and 12 had an anterior approach only. The overall complication rate was 19 % (39/201)--the most common being wound infection (n = 15, 8 %). There was no difference in the neurological outcome (Frankel grade) between Groups 1 and 2 (p = 0.34) or Groups 2 and 3 (p = 0.70). However, there was a significant difference between Groups 1 and 3 (p = 0.001), with Group 3 having a significantly better neurological outcome. Median survival was 93 days in Group 1, 229 days in Group 2 and 875 days in Group 3 (p = 0.001). The predictive value between the actual and predicted survival was 64 % (Group 1), 64 % (Group 2) and 69 % (Group 3). The overall predictive value of the revised Tokuhashi score using Cox regression for all groups was 66 %.

CONCLUSION

We would conclude that although the predictive value of the Tokuhashi score in terms of survival time is at best modest (66 %), the fact that there were statistically significant differences in survival between the groups looked at in this paper indicates that the scoring system, and the components which it consists of, are important in the evaluation of these patients when considering surgery.

Interruption of CXCL13-CXCR5 axis increases upper genital tract pathology and activation of NKT cells following chlamydial genital infection

BACKGROUND

Regulation of immune responses is critical for controlling inflammation and disruption of this process can lead to tissue damage. We reported that CXCL13 was induced in fallopian tube tissue following C. trachomatis infection. Here, we examined the influence of the CXCL13-CXCR5 axis in chlamydial genital infection.

METHODOLOGY AND PRINCIPAL FINDINGS

Disruption of the CXCL13-CXCR5 axis by injecting anti-CXCL13 Ab to BALB/c mice or using Cxcr5-/- mice increased chronic inflammation in the upper genital tract (UGT; uterine horns and oviducts) after Chlamydia muridarum genital infection (GT). Further studies in Cxcr5-/- mice showed an elevation in bacterial burden in the GT and increased numbers of neutrophils, activated DCs and activated NKT cells early after infection. After resolution, we noted increased fibrosis and the accumulation of a variety of T cells subsets (CD4-IFNγ, CD4-IL-17, CD4-IL-10 & CD8-TNFα) in the oviducts. NKT cell depletion in vitro reduced IL-17α and various cytokines and chemokines, suggesting that activated NKT cells modulate neutrophils and DCs through cytokine/chemokine secretion. Further, chlamydial glycolipids directly activated two distinct types of NKT cell hybridomas in a cell-free CD1d presentation assay and genital infection of Cd1d-/- mice showed reduced oviduct inflammation compared to WT mice. CXCR5 involvement in pathology was also noted using single-nucleotide polymorphism analysis in C. trachomatis infected women attending a sub-fertility clinic. Women who developed tubal pathology after a C. trachomatis infection had a decrease in the frequency of CXCR5 SNP +10950 T>C (rs3922).

CONCLUSIONS/SIGNIFICANCE

These experiments indicate that disruption of the CXCL13-CXCR5 axis permits increased activation of NKT cells by type I and type II glycolipids of Chlamydia muridarum and results in UGT pathology potentially through increased numbers of neutrophils and T cell subsets associated with UGT pathology. In addition, CXCR5 appears to contribute to inter-individual differences in human tubal pathology following C. trachomatis infection.

Glycolipids that elicit IFN-γ-biased responses from natural killer T cells

Natural killer T (NKT) cells recognize glycolipids presented by CD1d. The first antigen described, α-galactosyl ceramide (αGalCer), is a potential anticancer agent whose activity depends upon IFN-γ secretion. We report two analogs of αGalCer based on a naturally occurring glycosphingolipid, plakoside A. These compounds induce enhanced IFN-γ that correlates with detergent-resistant binding to CD1d and an increased stability of the lipid-CD1d complexes on antigen-presenting cells. Structural analysis on one of the analogs indicates that it is more deeply bound inside the CD1d groove, suggesting tighter lipid-CD1d interactions. To our knowledge, this is the first example in which structural information provides an explanation for the increased lipid-CD1d stability, likely responsible for the Th1 bias. We provide insights into the mechanism of IFN-γ-inducing compounds, and because our compounds activate human NKT cells, they could have therapeutic utility.

Weil osteotomy: assessment of medium term results and predictive factors in recurrent metatarsalgia

BACKGROUND

The angle of the Weil osteotomy is usually referenced relative to the floor irrespective of the plantar angulation of the metatarsal. This study aims to analyse the long term results following the Weil osteotomy and identify the cause of poor outcome.

METHODS

This study presents a retrospective review of 61 patients (86 feet), with mean follow-up of 31 months. Each patient underwent clinical, pedobarographic and radiological examination. The radiographs obtained included 'Metatarsal Skyline Views' (MSV), to assess the plantar declination of the metatarsal heads following the osteotomy. The functional scoring was performed using AOFAS and Foot Function Index.

RESULTS

Fifty-five patients (80 feet) showed good to excellent results clinically. Six patients had persistent metatarsalgia. All these 6 patients had callosities beneath metatarsal heads. Pedobarography showed peak pressures in the same distribution as callosities and the MSV showed increased plantar declination of the metatarsal heads. This correlation was found to be significant (p<0.05).

CONCLUSION

The Weil osteotomy is a safe and effective treatment for metatarsalgia. An MSV radiograph is helpful to identify the plantar prominence of metatarsal which can be associated with poor clinical outcomes.

Invariant NKT cells are required for airway inflammation induced by environmental antigens

House dust contains antigens capable of activating mouse and human iNKT cells, contributing to allergen-induced airway inflammation.

Invariant NKT cells (iNKT cells) are a unique subset of T lymphocytes that rapidly carry out effector functions. In this study, we report that a majority of sterile house dust extracts (HDEs) tested contained antigens capable of activating mouse and human iNKT cells. HDEs had adjuvant-like properties in an ovalbumin (OVA)-induced asthma model, which were dependent on Vα14i NKT cells, as vaccinated animals deficient for iNKT cells displayed significantly attenuated immune responses and airway inflammation. Furthermore, the administration of HDEs together with OVA mutually augmented the synthesis of cytokines by Vα14i NKT cells and by conventional CD4⁺ T cells in the lung, demonstrating a profound immune response synergy for both Th2 cytokines and IL-17A. These data demonstrate that iNKT cell antigens are far more widely dispersed in the environment than previously anticipated. Furthermore, as the antigenic activity in different houses varied greatly, they further suggest that iNKT cell responses to ambient antigens, particular to certain environments, might promote sensitization to conventional respiratory allergens.

Invariant NKT cells are crucial for airway inflammation induced by environmental antigens (163.22)

Invariant NKT (iNKT) cells are a unique subset of T lymphocytes that rapidly carry out effector functions. Here we report that a majority of sterile house dust extracts (HDEs) tested contained antigens capable of activating mouse and human iNKT cells. HDEs had adjuvant-like properties in an ovalbumin-induced asthma model, that were dependent on Vα14i NKT cells, as vaccinated animals deficient for iNKT cells displayed significantly attenuated immune responses and airway inflammation. Furthermore, the administration of HDEs together with ovalbumin mutually augmented the synthesis of cytokines by Vα14i NKT cells and by conventional CD4+ T cells in the lung, demonstrating a profound immune response synergy for both Th2 cytokines and IL-17A. These data demonstrate that iNKT cell antigens are far more widely dispersed in the environment than previously anticipated. Furthermore, as the antigenic activity in different houses varied greatly, they further suggest that iNKT cell responses to ambient antigens, particular to certain environments, might promote sensitization to conventional respiratory allergens.

Abstract P5-05-12: Heparan Sulfatase 2 Regulates Breast Cancer Tumorigenesis and Promotes Invasive Ductal Lesions

Ductal carcinoma in situ (DCIS) of the breast is a heterogenous group of proliferative cellular lesions that have the potential to become invasive. Very little is known about the molecular alterations involved in the progression from DCIS to invasive ductal carcinoma (IDC). Heparan endosulfatases HSulf-1 and -2 catalyze or edit sulfate moieties on heparan sulfate proteoglycans and have been implicated in modulating heparin binding growth factor signaling. Several studies have suggested that while expression of HSulf-1 is down-regulated and is considered a tumor suppressor gene, expression of HSulf-2 is over-expressed in primary breast tumors and cell lines. However, the role of HSulf-2 in breast tumorigenesis is poorly understood. Here we have evaluated the effect of HSulf-2 in an in vivo model of breast cancer progression (MCF10DCIS.com). These cells form comedo type DCIS and progress to IDC when transplanted in immune-deficient mice and therefore are an ideal model to study breast cancer progression.

Methods: Stable clones depleted of HSulf-2 in MCF10DCIS.com cells were generated and injected into mouse mammary fat pads with non-targeted control shRNA clones (NTC) as controls. HSulf-1, HSulf-2, smooth muscle actin immunostaining and H&E staining was perfromed at weeks 3, 5 and 7. Matrixmetallo Protease (MMP) expression by real time PCR was evaluated at Weeks 3 and 5 in both groups.

Results: A significant reduction in tumor growth was observed in HSulf-2 depleted clones compared to NTC clones (p=&lt;0.01). HSulf-2 immunohistochemical staining showed distinct pattern of staining localized to ductal lesions as well as stromal (myoepithelial and myofibroblasts cells). In contrast, the closely related family member, HSulf-1 expression was restricted largely to stromal and myoepithelial layer in ductal lesions. While HSulf-2 staining remained intense from weeks 3 to 7, HSulf-1 expression was diminished during the same time period. In NTC clones, ductal like lesions were observed by week 3 with disruption of the basement membrane and appearance of invasive phenotype by weeks 5 and 7. In contrast, HSulf2 knockdown xenografts showed retention of ductal like structures even at week 5 and retention of basement membrane (p=&lt;0.05). Additionally marked necrotic areas were also observed in HSulf-2 silenced clones. Previous studies have shown that the malignant epithelium induces the development of the stroma necessary for the development of invasive phenotype. Consistent with this observation, we demonstrated decreased MMP expression in xenografts derived from HSulf-2 depleted clones compared with NTC xenografts (p=&lt;0.05). Conclusions: Our data suggest that HSulf-2 may play an important role in the transition from DCIS to an invasive phenotype (IDC) potentially by up regulating MMP expression and activity.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-05-12.

Percutaneous fusion of the sacroiliac joint with hollow modular anchorage screws: clinical and radiological outcome

We reviewed 15 consecutive patients, 11 women and four men, with a mean age of 48.7 years (37.3 to 62.6), who between July 2004 and August 2007 had undergone percutaneous sacroiliac fusion using hollow modular anchorage screws filled with demineralised bone matrix. Each patient was carefully assessed to exclude other conditions and underwent pre-operative CT and MR scans. The diagnosis of symptomatic sacroiliac disease was confirmed by an injection of local anaesthetic and steroid under image intensifier control. The short form-36 questionnaire and Majeed's scoring system were used for pre- and post-operative functional evaluation. Post-operative radiological evaluation was performed using plain radiographs. Intra-operative blood loss was minimal and there were no post-operative clinical or radiological complications. The mean follow-up was for 17 months (9 to 39). The mean short form-36 scores improved from 37 (23 to 51) to 80 (67 to 92) for physical function and from 53 (34 to 73) to 86 (70 to 98) for general health (p = 0.037). The mean Majeed's score improved from 37 (18 to 54) pre-operatively to 79 (63 to 96) post-operatively (p = 0.014). There were 13 good to excellent results. The remaining two patients improved in short form-36 from a mean of 29 (26 to 35) to 48 (44 to 52). Their persistent pain was probably due to concurrent lumbar pathology. We conclude that percutaneous hollow modular anchorage screws are a satisfactory method of achieving sacroiliac fusion.

Natural Sphingomonas glycolipids vary greatly in their ability to activate natural killer T cells

Mouse natural killer T (NKT) cells expressing an invariant T cell antigen receptor (TCR) recognize glycosphingolipids (GSLs) from Sphingomonas bacteria. The synthetic antigens previously tested, however, were designed to closely resemble the potent synthetic agonist alpha-galactosyl ceramide (alphaGalCer), which contains a monosaccharide and a C18:0 sphingosine lipid. Some Sphingomonas bacteria, however, also have oligosaccharide-containing GSLs, and they normally synthesize several GSLs with different sphingosine chains including one with a cyclopropyl ring-containing C21:0 (C21cycl) sphingosine. Here we studied the stimulation of NKT cells with synthetic GSL antigens containing natural tetrasaccharide sugars, or the C21cycl sphingosine. Our results indicate that there is a great degree of variability in the antigenic potency of different natural Sphingomonas glycolipids, with the C21cycl sphingosine having intermediate potency and the oligosaccharide-containing antigens exhibiting limited or no stimulatory capacity.

Concurrent infection of pneumocystis pneumonia and pulmonary tuberculosis in an HIV-seronegative patient

Co-infection with Pneumocystis jirovecii and Mycobacterium tuberculosis is rarely reported in patients without human immunodeficiency virus (HIV) infection. We describe the case of a 33-year-old HIV-negative female patient who was on long-term oral corticosteroids for rheumatoid arthritis and admitted with for respiratory distress and diffuse infiltrative pneumopathy in whom concurrent infection with Mycobacterium tuberculosis and Pneumocystis jiroveci was confirmed by bronchoalveolar lavage (BAL) fluid examination.

Involvement of secretory and endosomal compartments in presentation of an exogenous self-glycolipid to type II NKT cells

Natural Killer T (NKT) cells recognize both self and foreign lipid Ags presented by CD1 molecules. Although presentation of the marine sponge-derived lipid alphaGalCer to type I NKT cells has been well studied, little is known about self-glycolipid presentation to either type I or type II NKT cells. Here we have investigated presentation of the self-glycolipid sulfatide to a type II NKT cell that specifically recognizes a single species of sulfatide, namely lyso-sulfatide but not other sulfatides containing additional acyl chains. In comparison to other sulfatides or alphaGalCer, lyso-sulfatide binds with lower affinity to CD1d. Although plate-bound CD1d is inefficient in presenting lyso-sulfatide at neutral pH, it is efficiently presented at acidic pH and in the presence of saposin C. The lysosomal trafficking of mCD1d is required for alphaGalCer presentation to type I NKT cells, it is not important for presentation of lyso-sulfatide to type II NKT cells. Consistently, APCs deficient in a lysosomal lipid-transfer protein effectively present lyso-sulfatide. Presentation of lyso-sulfatide is inhibited in the presence of primaquine, concanamycin A, monensin, cycloheximide, and an inhibitor of microsomal triglyceride transfer protein but remains unchanged following treatment with brefeldin A. Wortmannin-mediated inhibition of lipid presentation indicates an important role for the PI-3kinase in mCD1d trafficking. Our data collectively suggest that weak CD1d-binding self-glycolipid ligands such as lyso-sulfatide can be presented via the secretory and endosomal compartments. Thus this study provides important insights into the exogenous self-glycolipid presentation to CD1d-restricted T cells.

A method for production of recombinant mCD1d protein in insect cells

CD1 proteins constitute a third class of antigen-presenting molecules. They are cell surface glycoproteins, expressed as approximately 50-kDa glycosylated heavy chains that are noncovalently associated with beta2-microglobulin. They bind lipids rather than peptides. Although their structure confirms the similarity of CD1 proteins to MHC class I and class II antigen presenting molecules, the mCD1d groove is relatively narrow, deep, and highly hydrophobic and it has two binding pockets instead of the several shallow pockets described for the classical MHC-encoded antigen-presenting molecules. Based upon their amino acid sequences, such a hydrobphobic groove provides an ideal environment for the binding of lipid antigens. The Natural Killer T (NKT) cells use their TCR to recognize glycolipids bound to or presented by CD1d. T cells reactive to lipids presented by CD1 have been involved in the protection against autoimmune and infectious diseases and in tumor rejection. Thus, the ability to identify, purify , and track the response of CD1-reactive NKT cell is of great importance . The generation of tetramers of alpha Galactosyl ceramide (a-Galcer) with CD1d has significant insight into the biology of NKT cells. Tetramers constructed from other CD1 molecules have also been generated and these new reagents have greatly expanded the knowledge of the functions of lipid-reactive T cells, with potential use in monitoring the response to lipid-based vaccines and in the diagnosis of autoimmune diseases and other treatments.