Which Method for Diagnosing Small Fiber Neuropathy?

Introduction: Small fiber neuropathies (SFN) induce pain and/or autonomic symptoms. The diagnosis of SFN poses a challenge because the role of skin biopsy as a reference method and of each neurophysiological test remain to be discussed. This study compares six methods evaluating small sensory and autonomic nerve fibers: skin biopsy, Quantitative Sensory Testing (QST), quantitative sweat measurement system (Q-Sweat), Laser Evoked Potentials (LEP), Electrochemical Skin Conductance (ESC) measurement and Autonomic CardioVascular Tests (ACVT). Methods: This is a single center, retrospective study including patients tested for symptoms compatible with SFN between 2013 and 2016 using the afore-mentioned tests. Patients were ultimately classified according to the results and clinical features as "definite SFN," "possible SFN" or "no SFN." The sensitivity (Se) and specificity (Sp) of each test were calculated based on the final diagnosis and the best diagnostic strategy was then evaluated. Results: Two hundred and forty-five patients were enrolled (164 females (66.9%), age: 50.4 ± 15 years). The results are as follows: skin biopsy: Se = 58%, Sp = 91%; QST: Se = 72%, Sp = 39%; Q-Sweat: Se = 53%, Sp = 69%; LEP: Se = 66%, Sp = 89%; ESC: Se = 60%, Sp = 89%; Cardiovascular tests: Se = 15%, Sp = 99%. The combination of skin biopsy, LEP, QST and ESC has a Se of 90% and a Sp of 87%. Conclusion: Our study outlines the benefits of combining skin biopsy, ESC, LEP and QST in the diagnosis of SFN.

A 4-Year Retrospective Analysis of Salivary Gland Cytopathology Using the Milan System for Reporting Salivary Gland Cytology and Ancillary Studies

The cytopathology of salivary glands presents major challenges due to the heterogeneity of benign and malignant neoplasms, which is reflected in the large range of WHO 2017 Classifications. Fine needle aspiration (FNA) of salivary gland tumours is still the favoured initial approach as it results in good sensitivity and specificity. The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was published in 2018 and comprises seven categories. We report results from a 4-year retrospective analysis of 328 salivary gland FNAs which were reviewed and classified according to the MSRSGC. We assess the risk of neoplasm, the risk of malignancy and the contribution of ancillary studies to the diagnosis. Benign neoplasms were the most frequent diagnosis (44.2%). Malignant and suspicious for malignancy were identified in 11.3% and 4.9% of diagnosed cases, respectively. Histopathological analysis after surgery was available for 216 (65.8%) of the cases. All malignant cases were confirmed post-surgery, and 68.8% of suspicious for malignancy were confirmed as malignant tumours. Immunocytochemistry was informative in 72.3% of cases. Immunocytochemistry and FISH provided the definitive diagnosis in 23.7% and 33% of cases, respectively. In conclusion, the MSRSGC is more effective when specific features of neoplasms can be identified. Ancillary studies help to further characterise salivary gland tumours and thereby increase the accuracy of MSRSGC.

MIAmS: microsatellite instability detection on NGS amplicons data

MOTIVATION

Microsatellite instability (MSI) is a molecular marker of DNA mismatch repair deficiency frequently at play in oncogenesis. MSI testing is used for diagnostic, prognostic and therapeutic purposes in several cancers. The current gold standard analysis for microsatellite status is based on length distribution analysis of multiplex-PCR generated DNA fragments from tumor samples which is a laborious and time consuming method. Next generation sequencing (NGS) using amplicon panels is an easy, accurate and scalable technique to determine both the microsatellite status and tumor genome mutations at the same time. Here, we describe MIAmS, an application designed to tag microsatellite status from amplicon NGS of tumor samples. Interestingly, this tool does not require paired normal tissue for comparison. In addition, this scalable application provides a user-friendly report for the interpretation of the results by biologists and exhibits a strong accuracy and robustness for determination of the MSI status.

AVAILABILITY

https://github.com/bialimed/miams.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online, evaluation data are available at http://www.ebi.ac.uk/ena/data/view/PRJEB31725.

Rapid and Efficient Production of Human Functional Mast Cells through a Three-Dimensional Culture of Adipose Tissue-Derived Stromal Vascular Cells

Mast cells (MC) are innate immune cells involved in many physiological and pathological processes. However, studies of MC function and biology are hampered by the difficulties to obtain human primary MC. To solve this problem, we established a new method to produce easily and rapidly high numbers of MC for in vitro studies using human adipose tissue, which is an abundant and easy access tissue. Stromal vascular fraction of adipose tissue, obtained from human abdominal dermolipectomy, was cultured as spheroids in serum free medium supplemented in stem cell factor. Using this method, we generated, within 3 wk, a highly pure population of connective tissue-type MC expressing MC typical peptidases (tryptase, chymase, and carboxypeptidase-A3) with a yield increasing over time. Stem cell factor was required for this culture, but unlike MC derived from CD34⁺ cells, this culture did not depend on IL-3 and -6. MC obtained with this method degranulated following FcεRI cross-linking or stimulation by C5a, compound 48/80, and substance P. Interestingly, activation by anti-IgE of both white adipose tissue-MC and MC obtained from peripheral blood-derived CD34⁺ pluripotent progenitor cells induced the production of PGs as well as proinflammatory cytokines (TNF-α, Il-6, and GM-CSF). In conclusion, we developed a new time saving and reproducible method to produce highly pure and functional human MC in 3 wk from human adipose tissue.

Use of fluorescent in-situ hybridisation in salivary gland cytology: A powerful diagnostic tool

OBJECTIVE

Salivary gland cytology is challenging because it includes a diversity of lesions and a wide spectra of tumours. Recently, it has been reported that many types of salivary gland tumours have specific molecular diagnostic signatures that could be identified by fluorescent in-situ hybridisation (FISH). The aim of the present study was to demonstrate the feasibility and efficiency of FISH on routine cytological salivary gland smears.

METHODS

FISH was conducted on 37 cytological salivary gland smears from 34 patients. According to the cytological diagnosis suspected, MECT1/MAML2 gene fusion and rearrangements of PLAG1, MYB, or ETV6 were analysed. The presence and percentages of cells that had gene rearrangements were evaluated. Results were compared with the histological surgical samples, available from 26 patients.

RESULTS

The PLAG1 rearrangement was observed in 12/20 (60%) cases of pleomorphic adenoma. MECT1/MAML2 gene fusion was observed in 1:2 mucoepidermoid carcinomas but was not observed in five other tumours (two pleomorphic adenomas, one Warthin's tumour, one mammary analogue secretory carcinoma [MASC] and one cystic tumour). MYB rearrangement was observed in 4/4 adenoid cystic carcinomas. ETV6-gene splitting identified one MASC.

CONCLUSION

Overall, FISH had a specificity of 100% and a sensitivity of 66.7%. When FISH and cytological analyses were combined, the overall sensitivity was increased to 93.3%. It can thus be concluded that when the FISH analysis is positive, the extent of surgery could be determined with confidence pre-operatively without needing a diagnosis from a frozen section.

Targeting VEGFR1 on endothelial progenitors modulates their differentiation potential

OBJECTIVES

We studied whether plasma levels of angiogenic factors VEGF and placental growth factor (PlGF) in coronary artery disease patients or undergoing cardiac surgery are modified, and whether those factors modulate endothelial progenitor's angiogenic potential.

METHODS AND RESULTS

A total of 143 patients' plasmas from two different studies were analyzed (30 coronary artery disease patients, 30 patients with stable angina, coupled with 30 age and sex-matched controls; 53 patients underwent cardiac surgery). Among factors screened, only PlGF was found significantly increased in these pathological populations. PlGF-1 and PlGF-2 were then tested on human endothelial-colony-forming cells (ECFCs). We found that PlGF-1 and PlGF-2 induce VEGFR1 phosphorylation and potentiate ECFCs tubulogenesis in vitro. ECFCs VEGFR1 was further inhibited using a specific small interfering RNA (siRNA) and the chemical compound 4321. We then observed that the VEGFR1-siRNA and the compound 4321 decrease ECFCs tubulogenesis potential in vitro. Finally, we tested the compound 4321 in the preclinical Matrigel(®)-plug model with C57Bl/6J mice as well as in the murine hindlimb ischemia model. We found that 4321 inhibited the plug vascularization, attested by the hemoglobin content and the VE-Cadherin expression level and that 4321 inhibited the post-ischemic revascularization.

CONCLUSION

PlGF plasma levels were found increased in cardiovascular patients. Disrupting PlGF/VEGFR1 pathway could modulate ECFC-induced tubulogenesis, the cell type responsible for newly formed vessels in vivo.

The profibrotic cytokine transforming growth factor-β1 increases endothelial progenitor cell angiogenic properties

BACKGROUND

Transforming growth factor-β1 (TGF-β1) is a profibrotic cytokine that plays a major role in vascular biology, and is known to regulate the phenotype and activity of various vascular cell populations. Because most fibrotic diseases, such as idiopathic pulmonary fibrosis (IPF), are associated with vascular remodeling, and as endothelial progenitor cells (EPCs) may be involved in this process, we investigated the impact of TGF-β1 modulation of EPC angiogenic properties.

METHODS

TGF-β1 plasma levels were determined in 64 patients with IPF and compared with those in controls. The effect of TGF-β1 on angiogenesis was studied in vivo in a Matrigel plug model and in vitro on endothelial colony-forming cells (ECFCs). We studied the effects of inhibiting the expression of the three main receptors of TGF-β1 in ECFCs by using short interfering RNA.

RESULTS

Total TGF-β1 plasma levels were significantly increased in patients with IPF as compared with controls (P < 0.0001). TGF-β1 had proangiogenic effects in vivo by increasing hemoglobin content and blood vessel formation in Matrigel plugs implanted in C57/Bl6 mice, and in vitro by enhancing ECFC viability and migration. The effects were abolished by silencing the three main TGF-β1 receptors.

CONCLUSIONS

TGF-β1 is proangiogenic in vivo and induces ECFC angiogenic properties in vitro, suggesting that TGF-β1 may play a role during vascular remodeling in fibrotic disease states via EPCs.