Immunohistopathology of oral mucosal chronic graft-versus-host disease severity and duration.

OBJECTIVE: Chronic graft-versus-host disease (cGVHD) is the main cause of late non-relapse mortality following hematopoietic cell transplantation. Oral mucosal (om-) cGVHD is common, but diagnosis and assessment rely on clinical interpretation and patient-reported symptoms. We investigated immunohistopathological profiles with respect to om-cGVHD severity disease duration. MATERIAL AND METHODS: Ninety-four transplant patients and 15 healthy controls (n = 212 biopsies) were investigated by quantitative immunohistochemistry for T cells (CD4, CD8, and CD5), B cells (CD19 and CD20), macrophages (CD68), and Langerhans cells (CD1a). RESULTS: We found significant increases in T (CD4, CD8) and monocytic (CD68) cells in om-cGVHD, and a notable absence of B (CD19 and CD20) cells. Histopathological activity correlated with increased CD4, CD8 and CD68. However, CD4 was associated with mild om-cGVHD, whereas CD8 and CD68 were found to be elevated in severe om-cGVHD. CD8 and CD68 levels were raised at disease onset, but during late phase, the predominant CD68 population was accompanied by CD4. CONCLUSION: Oral cGVHD is a heterogenous clinical disorder, but our knowledge of the underlying biology remains limited. We highlight the importance of CD4, CD8 and CD68 immune profiling, together with histological grading for the staging of oral cGVHD, to broaden our understanding of the biology and individual disease course.

Histopathological Grading of Oral Mucosal Chronic Graft-versus-Host Disease: Large Cohort Analysis.

Graft-versus-host disease (GVHD) can manifest as acute or chronic complications in patients after hematopoietic cell transplantation (HCT). Oral chronic GVHD (cGVHD) occurs in approximately 70% of HCT recipients and includes lichenoid-like mucosal reactions, restricted mouth opening, and salivary gland dysfunction. However, the underlying histopathological presentation remains to be validated in large cohorts. We characterized the histopathological features of oral mucosal cGVHD and devised a scoring model in a large patient cohort (n = 112). Oral mucosal biopsy sections (n = 303) with and without oral cGVHD were identified from archived and current HCT recipients with additional healthy controls. Histological screening was performed on hematoxylin and eosin-stained and periodic acid-Schiff-stained sections. A points-based grading tool (0 to 19, grade 0 to IV) was established based on intraepithelial lymphocytes and band-like inflammatory infiltrate, atrophic epithelium with basal cell liquefaction degeneration, including apoptosis, as well as separation of epithelium and pseudo-rete ridges. Validation involved 62 biopsy specimens, including post-HCT (n = 47) and healthy (n = 15) specimens. Remaining biopsy specimens (n = 199) were blindly graded by 3 observers. Histological severity was correlated with clinical diagnostic and distinctive features, demonstrating a spectrum of individual patient severity, including frequent signs of subclinical GVHD in healthy mucosa. However, oral cGVHD presented with significantly higher (P < .001) scores compared with HCT controls, with moderate to high positive likelihood ratios for inflammatory infiltrate, exocytosis, and basal membrane alterations. The grade II-IV biopsy specimens demonstrated a histopathological diagnosis of active mucosal lichenoid-like cGVHD, highlighting the importance of correlating clinical presentation with the dynamic histopathological processes for improved patient stratification. In addition, this tool could be used for assessing treatments, pathological processes, and immune cellular content to provide further insight into this debilitating disease.

Tissue-resident MAIT cell populations in human oral mucosa exhibit an activated profile and produce IL-17.

Mucosa-associated invariant T (MAIT) cells are unconventional T lymphocytes defined by their innate-like characteristics and broad antimicrobial responsiveness. Whether MAIT cells are part of the tissue-resident defense in the oral mucosal barrier is unknown. Here, we found MAIT cells present in the buccal mucosa, with a tendency to cluster near the basement membrane, and located in both epithelium and the underlying connective tissue. Overall MAIT cell levels were similar in the mucosa compared to peripheral blood, in contrast to conventional T cells that showed an altered representation of CD4+ and CD8+ subsets. The major mucosal MAIT cell subset displayed a tissue-resident and activated profile with high expression of CD69, CD103, HLA-DR, and PD-1, as well as a skewed subset distribution with higher representation of CD4- /CD8- double-negative cells and CD8αα+ cells. Interestingly, tissue-resident MAIT cells had a specialized polyfunctional response profile with higher IL-17 levels, as assessed by polyclonal stimulus and compared to tissue nonresident and circulating populations. Furthermore, resident buccal MAIT cells were low in perforin. Together, these data indicate that MAIT cells form a part of the oral mucosal T cell compartment, where they exhibit a tissue-resident-activated profile biased toward IL-17 production.

Mycobiota profile of oral fungal infections in head and neck cancer patients receiving radiotherapy: A 6-year retrospective MALDI-TOF mass spectrometry study.

OBJECTIVES: Head and neck cancer (HNC) impairs patient immunity and increases susceptibility to oral fungal infections (OFIs). Effectively treating such infections requires accurate identification of the causative pathogens. This study aimed to characterize the mycobiota profile of OFIs in HNC patients undergoing radiation treatment (RT). MATERIALS AND METHODS: A 6-year retrospective analysis of oral mucosal samples from HNC patients with a history of RT and OFIs between 2014 and 2019 was conducted using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) profiling. Samples from the Clinical Microbiology Laboratory at Karolinska University Hospital were evaluated for mycobiota diversity and species co-occurrence patterns in the ongoing-RT and post-RT groups. RESULTS: A total of 190 oral fungi (88% Candida, 5% Pichia) were isolated from 162 HNC patients receiving RT. In the ongoing-RT group, the emergent non-albicans Candida (NAC) species; F. solani and C. jadinii, were detected for the first time. The dominant pathogens in both ongoing and post-RT groups were C. albicans, C. glabrata, P. kudriavzevii, C. parapsilosis, and C. tropicalis, as shown by Venn analysis. Network analysis revealed greater fungi diversity and multi-species co-occurrence in the ongoing-RT group. C. albicans commonly co-occurred with C. glabrata in both ongoing-RT (21%) and post-RT groups (30%). CONCLUSION: MALDI-TOF MS identified a wide range of oral fungal species in HNC patients receiving RT. While C. albicans remains the most prevalent OFIs pathogen, multi-species co-occurrence and novel NACs were noted. Understanding the ecological interactions among these causative pathogens could significantly advance the development of effective therapeutics for treating OFIs in HNC patients.

A mutant thyroid hormone receptor alpha antagonizes peroxisome proliferator-activated receptor alpha signaling in vivo and impairs fatty acid oxidation.

Thyroid hormone regulates the balance between lipolysis and lipogenesis. We previously reported that male mice with a dominant-negative P398H mutation introduced into the TRalpha gene have visceral obesity, hyperleptinemia, and reduced catecholamine-stimulated lipolysis in white adipose tissue. Based on our observation of hepatic steatosis in the TRalpha P398H male mice, we used in vitro and in vivo models to investigate the influence of the TRalpha P398H mutant on peroxisome proliferator-activated receptor-alpha (PPARalpha) signaling. Wild-type TRalpha and the P398H mutant significantly reduced PPARalpha-mediated transcription in transient transfection assays. T(3) reversed the inhibition of PPARalpha action by wild-type TRalpha but not the P398H mutant. Chromatin immunoprecipitation assays demonstrated that the P398H mutant reduces PPARalpha binding to peroxisome proliferator receptor elements. In gel shift assays, the P398H mutant directly bound the peroxisome proliferator-activated receptor response element and inhibited PPARalpha binding, which was not reversed by addition of retinoid X receptor. The TRalpha R384C and PV dominant-negative mutants are not associated in vivo with a metabolic phenotype and had reduced (PV) or absent (R384C) PPARalpha inhibition compared with P398H. The metabolic phenotype of the P398H mutant mice is due, in part, to unique properties of the P398H mutant receptor interfering with PPARalpha signaling. The P398H mutant is a potential probe to characterize the physiological role of thyroid hormone receptor/PPARalpha interactions.

Ameloblastoma RNA profiling uncovers a distinct non-coding RNA signature.

Ameloblastoma of the jaws remains the top difficult to treat odontogenic tumour and has a high recurrence rate. New evidence suggests that non-coding RNAs (ncRNAs) play a critical role in tumourgenesis and prognosis of cancer. However, ameloblastoma ncRNA expression data is lacking. Here we present the first report of ameloblastoma ncRNA signatures. A total of 95 ameloblastoma cases and a global array transcriptome technology covering > 285.000 full-length transcripts were used in this two-step analysis. The analysis first identified in a test cohort 31 upregulated ameloblastoma-associated ncRNAs accompanied by signalling pathways of cancer, spliceosome, mRNA surveillance and Wnt. Further validation in an independent cohort points out the long non-coding (lncRNAs) and small nucleolar RNA (snoRNAs): LINC340, SNORD116-25, SNORA11, SNORA21, SNORA47 and SNORA65 as a distinct ncRNA signature of ameloblastoma. Importantly, the presence of these ncRNAs was independent of BRAF-V600E and SMO-L412F mutations, histology type or tumour location, but was positively correlated with the tumour size. Taken together, this study shows a systematic investigation of ncRNA expression of ameloblastoma, and illuminates new diagnostic and therapeutic targets for this invasive odontogenic tumour.

Implementation of a Web-Based Patient Simulation Program to Teach Dental Students in Oral Surgery.

The aim of this study was to evaluate a web-based simulation of patients (Web-SP) program on learning skills in clinical reasoning and patient evaluation in the oral surgery education of third-year dental students. A secondary aim was to investigate the program's effect on students' learning, knowledge, and attitudes towards virtual patient simulations. Authentic virtual oral surgery patient cases were created at a dental school in Sweden using the Web-SP platform. The Web-SP program was introduced in a two-hour seminar. A 20-minute pre-seminar test (test A) was administered to assess the students' knowledge of oral surgery prior to experiencing the Web-SP program. Ten days after the seminar, another test (test B) was administered to evaluate the increase in oral surgery knowledge as a result of using the program, and an emailed survey of the students was conducted. Of 70 students in the course, 67 (95.7%) agreed to participate in the study and took test A; of these, 59 (88%) took test B. Of the 59 students who took both tests, 28 (42%) completed the survey. The results of the two tests showed a statistically significant increase in knowledge, which was in accordance with the learning goals (p<0.0001). The survey results showed that the students had a positive attitude towards the teaching method. In this study, Web-SP was found to be a valuable tool for teaching clinical reasoning and patient evaluation in an undergraduate oral surgery education setting by improving learning outcomes in comparison with traditional teaching alone.

Rapid progression from subclinical to symptomatic overt hypothyroidism.

OBJECTIVE: To report a case of Hashimoto's thyroiditis with rapid progression from subclinical to overt symptomatic hypothyroidism and to discuss the potential precipitating factors and the implications on clinical decisions about monitoring and treatment of early thyroid failure. METHODS: We describe a patient with long-standing subclinical hypothyroidism who had progression to severe overt hypothyroidism during a 2-month period, without an identifiable precipitating factor. All medical care was provided at a single institution, and all relevant medical records were reviewed. RESULTS: For at least 2 years, an 84-year-old man had a pattern of subclinical hypothyroidism, including normal levels of serum free thyroxine, serum thyrotropin concentrations ranging from 4.4 to 9.6 microIU/mL, and elevated levels of anti-thyroid peroxidase antibodies. During a 2-month period, symptoms of cold intolerance, a 4.5-kg weight gain, and fatigue developed, and the patient was found to have low free thyroxine and free triiodothyronine concentrations and a serum thyrotropin concentration of 80.9 microIU/mL. The patient did not use any medication previously identified as a trigger to the development of hypothyroidism, had no exposure to iodine or contrast administration, and reported no intercurrent infection that might explain the rapid progression of hypothyroidism. CONCLUSION: Most patients with subclinical hypothyroidism have progression to overt hypothyroidism at a slow rate. Elderly patients with high antithyroid antibody titers may have a higher than previously recognized risk of rapid development of overt hypothyroidism, and earlier intervention with levothyroxine treatment may be indicated.

Anaplastic thyroid carcinoma with thyrotoxicosis and hypoparathyroidism.

OBJECTIVE: To describe a patient who presented with anaplastic thyroid carcinoma and thyrotoxicosis in whom hypoparathyroidism developed. METHODS: We present the clinical and laboratory findings in a patient with anaplastic thyroid carcinoma and thyrotoxicosis. We also review the literature for previous cases of anaplastic thyroid carcinoma with thyrotoxicosis. RESULTS: A 74-year-old man presented with left-sided neck pain and a rapidly enlarging neck mass. Initial thyroid function tests revealed the following: thyrotropin (thyroid-stimulating hormone or TSH) 0.03 microIU/mL, free thyroxine 1.28 ng/dL, and total triiodothyronine 119 ng/dL. A thyroid radioiodine uptake scan was 2.2% at 25 hours. Pathology examination of the neck mass disclosed anaplastic thyroid carcinoma. His thyrotoxicosis was managed with beta-adrenergic blockade. The thyroid carcinoma was treated palliatively with external beam irradiation. During week 9 after the patient's initial presentation, symptomatic hypocalcemia developed, with an ionized serum calcium level of 0.75 mmol/L (normal range, 1.15 to 1.29) and a parathyroid hormone level of 21.2 pg/mL (normal range, 10 to 65). He was given calcium gluconate intravenously for initial management, followed by orally administered calcium carbonate and calcitriol. At week 15, he died of complications attributable to anaplastic thyroid carcinoma. CONCLUSION: Thyrotoxicosis due to thyroiditis is a rare initial manifestation of anaplastic thyroid carcinoma. Hypoparathyroidism due to anaplastic thyroid carcinoma has not been reported previously.

Computational analysis of isoform-specific signal regulation by CEACAM1-A cell adhesion molecule expressed in PC12 cells.

CEACAM1 is a signal-regulating, homophilic cell adhesion receptor system expressed in epithelia, vessel endothelia, and leukocytes. Here, we demonstrate that CEACAM1 is expressed also in PC12 cells, both as the common transmembrane isoforms, CEACAM1-L and CEACAM1-S, and as a novel, secreted, differentially spliced isoform. CEACAM1 can have both positive and negative effects on cell signaling. In an attempt to explain this dual behavior, we have initiated computational analysis of the signal-regulating effects of CEACAM1. This suggests that CEACAM1 can exert its signal-regulating activities by discriminating between binding of Src kinases and SHP phosphatases, respectively. Major factors that regulate this discrimination are the expression levels and expression ratios of transmembrane CEACAM1-L and CEACAM1-S, the concentration of secreted CEACAM1, and homophilic binding of CEACAM1 presented by neighboring cells.

Carcinoembryonic antigen-related cell adhesion molecule 1 expression and signaling in human, mouse, and rat leukocytes: evidence for replacement of the short cytoplasmic domain isoform by glycosylphosphatidylinositol-linked proteins in human leukocytes.

Carcinoembryonic Ag-related cell adhesion molecule 1 (CEACAM1), the primordial carcinoembryonic Ag gene family member, is a transmembrane cell adhesion molecule expressed in leukocytes, epithelia, and blood vessel endothelia in humans and rodents. As a result of differential splicing, CEACAM1 occurs as several isoforms, the two major ones being CEACAM1-L and CEACAM1-S, that have long (L) or short (S) cytoplasmic domains, respectively. The L:S expression ratios vary in different cells and tissues. In addition to CEACAM1, human but not rodent cells express GPI-linked CEACAM members (CEACAM5-CEACAM8). We compared the expression patterns of CEACAM1-L, CEACAM1-S, CEACAM6, and CEACAM8 in purified populations of neutrophilic granulocytes, B lymphocytes, and T lymphocytes from rats, mice, and humans. Human granulocytes expressed CEACAM1, CEACAM6, and CEACAM8, whereas human B lymphocytes and T lymphocytes expressed only CEACAM1 and CEACAM6. Whereas granulocytes, B cells, and T cells from mice and rats expressed both CEACAM1-L and CEACAM1-S in ratios of 2.2-2.9:1, CEACAM1-S expression was totally lacking in human granulocytes, B cells, and T cells. Human leukocytes only expressed the L isoforms of CEACAM1. This suggests that the GPI-linked CEACAM members have functionally replaced CEACAM1-S in human leukocytes. Support for the replacement hypothesis was obtained from experiments in which the extracellular signal-regulated kinases (Erk)1/2 were activated by anti-CEACAM Abs. Thus, Abs against CEACAM1 activated Erk1/2 in rat granulocytes, but not in human granulocytes. Erk1/2 in human granulocytes could, however, be activated by Abs against CEACAM8. We demonstrated that CEACAM1 and CEACAM8 are physically associated in human granulocytes. The CEACAM1/CEACAM8 complex in human cells might accordingly play a similar role as CEACAM1-L/CEACAM1-S dimers known to occur in rat cells.

E- and N-cadherin distribution in developing and functional human teeth under normal and pathological conditions.

Cadherins are calcium-dependent cell adhesion molecules involved in the regulation of various biological processes such as cell recognition, intercellular communication, cell fate, cell polarity, boundary formation, and morphogenesis. Although previous studies have shown E-cadherin expression during rodent or human odontogenesis, there is no equivalent study available on N-cadherin expression in dental tissues. Here we examined and compared the expression patterns of E- and N-cadherins in both embryonic and adult (healthy, injured, carious) human teeth. Both proteins were expressed in the developing teeth during the cap and bell stages. E-cadherin expression in dental epithelium followed an apical-coronal gradient that was opposite to that observed for N-cadherin. E-cadherin was distributed in proliferating cells of the inner and outer enamel epithelia but not in differentiated cells such as ameloblasts, whereas N-cadherin expression was up-regulated in differentiated epithelial cells. By contrast to E-cadherin, N-cadherin was also expressed in mesenchymal cells that differentiate into odontoblasts and produce the hard tissue matrix of dentin. Although N-cadherin was not detected in permanent intact teeth, it was re-expressed during dentin repair processes in odontoblasts surrounding carious or traumatic sites. Similarly, N-cadherin re-expression was seen in vitro, in cultured primary pulp cells that differentiate into odontoblast-like cells. Taken together these results suggest that E- and N-cadherins may play a role during human tooth development and, moreover, indicate that N-cadherin is important for odontoblast function in normal development and under pathological conditions.