In Vitro Differentiation of Human Skin-Derived Cells into Functional Sensory Neurons-Like.

Skin-derived precursor cells (SKPs) are neural crest stem cells that persist in certain adult tissues, particularly in the skin. They can generate a large type of cell in vitro, including neurons. SKPs were induced to differentiate into sensory neurons (SNs) by molecules that were previously shown to be important for the generation of SNs: purmorphamine, CHIR99021, BMP4, GDNF, BDNF, and NGF. We showed that the differentiation of SKPs induced the upregulation of neurogenins. At the end of the differentiation protocol, transcriptional analysis was performed on BRN3A and a marker of pain-sensing nerve cell PRDM12 genes: 1000 times higher for PRDM12 and 2500 times higher for BRN3A in differentiated cells than they were in undifferentiated SKPs. Using immunostaining, we showed that 65% and 80% of cells expressed peripheral neuron markers BRN3A and PERIPHERIN, respectively. Furthermore, differentiated cells expressed TRPV1, PAR2, TRPA1, substance P, CGRP, HR1. Using calcium imaging, we observed that a proportion of cells responded to histamine, SLIGKV (a specific agonist of PAR2), polygodial (a specific agonist of TRPA1), and capsaicin (a specific agonist of TRPV1). In conclusion, SKPs are able to differentiate directly into functional SNs. These differentiated cells will be very useful for further in vitro studies.

A case of IgE myeloma transformed into IgE-producing plasma cell leukaemia.

This is a case report of a challenging diagnosis of IgE monoclonal gammopathy of undetermined significance, which transformed into myeloma, then transformed into IgE-producing plasma cell leukaemia in a 71-year-old male who was followed in Brest, France, from 2015 to 2019. The IgE-producing variant is the rarest sub-type of multiple myeloma, and plasma cell leukaemia is considered to be the rarest and the most aggressive of human monoclonal gammopathies. In November 2015, hypogammaglobulinemia was detected during a systematic check-up. A kappa light chain monoclonal gammopathy was first diagnosed due to an increase of the free kappa/lambda light chains ratio. No monoclonal immunoglobulin was detected by either serum protein electrophoresis (Capillarys 2, Sebia, Issy-les-Moulineaux, France) or immunofixation (Hydrasys 2, Sebia, Issy-les-Moulineaux, France). In June 2018, a blood smear led to the diagnosis of plasma cell leukaemia. A monoclonal peak was detected and identified as IgE-kappa. Analysis of an archival sample taken three years earlier, revealed the presence of a monoclonal IgE, which had been missed at diagnosis. Chemotherapy with bortezomib and dexamethasone was introduced. The patient survived 10 months after the diagnosis of leukaemia. This case shows that an abnormal free light chain ratio should be considered as a possible marker of IgE monoclonal gammopathy even in the absence of a solitary light chain revealed by immunofixation. In addition, the use of an undiluted serum may increase the sensitivity of the immunofixation for the detection of IgE monoclonal gammopathies compared to the 1:3 dilution recommended by the manufacturer.

Aquagenic pruritus in essential thrombocythemia is associated with a higher risk of thrombosis.

BACKGROUND: Thromboses and phenotypic evolutions (leukemia, myelofibrosis) are the most frequent complications in polycythemia vera (PV) and essential thrombocythemia (ET). Aquagenic pruritus (AP) is not only PV symptom, but is also present in ET. The presence of pruritus in PV is associated with a lower risk of arterial thrombosis. AIMS: To date, no equivalent study has been done to analyse the impact of AP for ET patients. MATERIALS & METHODS: We used the data from our cohort of patients with myeloproliferative neoplasms seen in our institution (OBENE database, NCT02897297). We collect information at diagnosis, presence or not of AP and all types of complications during their follow-up. To avoid masked PV, all JAK2 positive cases were tested isotopic red mass cell if appropriate. RESULTS: Among 396 ET patients, presence of AP was found in 42 (10.6%). ET patients with AP were more proliferative, more symptomatic at diagnosis and more difficult to treat. Furthermore, they presented increased risk of thromboses (30.9 versus 17%, P = .03; OR = 2.2 [1.01;4.66]) and phenotypic evolutions (33.3 versus 13.3%, P = .0007; OR = 3.2 [1.44;6.77]), during follow-up. DISCUSSION: Aquagenic pruritus is classically associated to PV. But we confirmed here that AP is also present in ET and characterizes patients with higher risk of morbidity (thrombotic events and phenotypic evolutions). CONCLUSIONS: The systematic determination of the presence of AP in ET patients should permit us to better identify these high-risk patients for better management and follow-up.

Immune Checkpoint Inhibitors in Melanoma: A Review of Pharmacokinetics and Exposure-Response Relationships.

Immune checkpoint inhibitors are a new class of monoclonal antibodies that amplify T-cell-mediated immune responses against cancer cells. The introduction of these new drugs, first anti-cytotoxic T-lymphocyte-associated protein 4 (anti-CTLA4) and then anti-programmed death-1 (anti-PD1), was a major improvement in the treatment of advanced or metastatic melanoma, a highly immunogenic tumour. The development strategy for immune checkpoint immunotherapies differed from that traditionally used for cytotoxic therapies in oncology. The choices of doses at which to conduct clinical trials, and subsequently the choice of doses at which to use these new therapies, were not based on the identification of a maximum tolerated dose from dose-escalation studies; thus, pharmacokinetic and pharmacokinetic-pharmacodynamic modelling was essential. The studies conducted have shown that the pharmacokinetics of ipilimumab were linear and not time-dependent. In addition, there was a correlation between the trough concentrations of ipilimumab and its therapeutic efficacy. On the contrary, the anti-PD1 immunotherapies nivolumab and pembrolizumab had time-dependent pharmacokinetics. Their therapeutic efficacy was not related to their trough concentration, but there was a correlation between the clearance of anti-PD1 and the survival of melanoma patients. This review highlights the complexity of interpreting the exposure-response relationships of these agents. Further studies are needed to assess the value of therapeutic drug monitoring of immune checkpoint inhibitors in the treatment of melanoma.

Systematic overestimation of human serum albumin by capillary zone electrophoresis method due to monoclonal immunoglobulin interferences.

BACKGROUND: The capillary zone electrophoresis method of albumin measurement is frequently used in monoclonal gammopathy patients but some studies suggest poor performances of the method in this population. The aim of this study was to analyse the impact of serum monoclonal immunoglobulins on human serum albumin determination by capillary zone electrophoresis method compared to other available methods. METHOD: We prospectively measured albumin in 100 freshly collected non-frozen serum samples in a monoclonal gammopathy patients population, by using four different methods: the capillary zone electrophoresis method, the bromocresol purple dye method, the nephelometric method and the turbidimetric method. Differences in albumin values between the different methods were analysed with respect to serum monoclonal immunoglobulin concentration. These differences were further investigated by measuring albumin levels in human serum samples spiked with exogenous monoclonal immunoglobulins. RESULTS: Human serum albumin difference values between capillary zone electrophoresis compared to immunonephelometry method are significantly correlated with increasing monoclonal immunoglobulins concentrations: regression analyses revealed a correlation coefficient r2 = 0.60 and a slope of 0.14 (0.12-0.17, 95% confidence interval). The capillary zone electrophoresis method overestimated serum albumin levels by up to 67% (12 g/L) when monoclonal immunoglobulin level was 63 g/L. The determination of albumin levels in human serum samples spiked with exogenous monoclonal immunoglobulins showed an overestimation of human serum albumin measurement by the capillary zone electrophoresis method proportional to the amount of monoclonal immunoglobulin added in the serum with a slope of 0.19 (0.18-0.20, 95% confidence interval). CONCLUSION: Monoclonal immunoglobulins directly interfere with serum albumin measurement by the capillary zone electrophoresis method leading to a systematic overestimation of serum albumin concentrations proportional to the serum monoclonal immunoglobulin level.

Is capillary zone electrophoresis a suitable method for estimating serum albumin: A comparison of four methods.

BACKGROUND: The capillary zone electrophoresis method of albumin measurement is frequently used for oncologic and haematologic patients but few data exist about the agreement between the albumin measurements performed by capillary zone electrophoresis and other methods. The aim of this study was to analyse the agreement between human serum albumin measurements by capillary zone electrophoresis and by the nephelometry, bromocresol purple and turbidimetry methods. METHOD: We prospectively measured 100 freshly collected non-frozen patient serum samples, by using four different methods: the capillary zone electrophoresis method performed with a CAPILLARYS 2 instrument, the bromocresol purple dye method performed with an Advia XPT analyser, the nephelometric method performed with a BN ProSpec analyser and the turbidimetric method with reagents from DiAgam and performed with the Advia XPT analyser. RESULTS: A bias towards higher values in the lower range of albumin concentrations was observed with capillary zone electrophoresis compared to immunonephelometry: correlation coefficient r2 = 0.925; slope of 0.86 (0.82-0.89, 95% confidence interval), which is significantly different from 1; and an intercept of 4.94 g/L (3.67-6.16, 95% confidence interval). Similar results were observed when comparing capillary zone electrophoresis to the bromocresol purple and immunoturbidimetry methods. The capillary electrophoresis method overestimated low albumin levels by up to 25% (5 g/L). CONCLUSION: Compared to the nephelometry, turbidimetry and bromocresol purple methods, the capillary zone electrophoresis method tends to overestimate human serum albumin concentrations for levels below 30 g/L. This discrepancy could lead to an overestimation of the nutritional status, an inappropriate scoring of the disease and a delay in nutritional treatment.

[Biological diagnosis of pheochromocytoma: is there an interest in urinary metanephrines measurement over 3 consecutive days?] / Diagnostic biologique du phéochromocytome : le dosage des dérivés méthoxylés urinaires sur 3 jours consécutifs présente-t-il un intérêt ?

Pheochromocytoma and paraganglioma are neuroendocrine tumors characterized by a catecholamine production potential. The biochemical diagnosis for this type of tumor is carried out through the metanephrine titration on 24-hours urines. Some authors have suggested that the sensitivity of the test could be improved by sampling and analyzing urines 3 days in a row (cycle) versus a unique measurement but this method has never been fully evaluated. The goal of this study was to establish a comparison of diagnosis performances between urinary metanephrines measurement for 3 consecutive days, and metanephrines measurement on a unique 24-hour sample. Patients of Brest Regional University Hospital whose 3-consecutive day 24-hour urine samples had been analyzed from January 2011 to May 2017 were included in this study. The primary endpoint was the comparison of diagnostic performances of urinary metanephrine titration over a single day versus 3 consecutive days. Eighty-two patients for a total of 103 cycles among which 7 revealed a pheochromocytoma were analyzed. ROC curve analysis shows that the metanephrine cycle titration method is more efficient than the metanephrine single titration method (metanephrine: AUC=0.881 against 0.826 respectively; normetanephrine: AUC=0.946 against 0.901 respectively). Urinary titration over 3 days allows the diagnosis of 100% (7/7) of pheochromocytomas against 85.7% (6/7) for the the single urinary titration. In conclusion, metanephrine titration over 3 consecutive days of 24-hours urine samples shows a better sensitivity and better diagnosis performances for detecting pheochromocytoma and paraganglioma than the single titration method.

A new tool to test active ingredient using lactic acid in vitro, a help to understand cellular mechanism involved in stinging test: An example using a bacterial polysaccharide (Fucogel® ).

The stinging test is an in vivo protocol that evaluates sensitive skin using lactic acid (LA). A soothing sensation of cosmetics or ingredients can be also appreciated through a decrease in stinging score. To predict the soothing sensation of a product before in vivo testing, we developed a model based on an LA test and substance P (SP) release using a co-culture of human keratinocytes and NGF-differentiated PC12 cells. A bacterial fucose-rich polysaccharide present in Fucogel® was evaluated as the soothing molecule in the in vivo stinging test and our in vitro model. Excluding toxic concentrations, the release of SP was significant from 0.2% of lactic acid for the PC12 cells and from 0.1% of lactic acid for the keratinocytes. When the pH was adjusted to approximately 7.4, LA did not provoke SP release. At these concentrations of LA, 0.1% of polysaccharide showed a significant decrease in SP release from the two cellular types and in co-cultures without modifying the pH of the medium. In vivo, a stinging test using the polysaccharide showed a 30% decrease in prickling intensity vs the placebo in 19 women between the ages of 21 and 69. Our in vitro model is ethically interesting and is adapted for cosmetic ingredients screening because it does not use animal experimentation and limits human volunteers. Moreover, Fucogel® reduced prickling sensation as revealed by the in vivo stinging test and inhibits the neurogenic inflammation as showed by our new in vitro stinging test based on SP release.

The presence of monoclonal gammopathy in Ph-negative myeloproliferative neoplasms is associated with a detrimental effect on outcomes.

Many case reports have indicated the occurrence of monoclonal gammopathy of uncertain significance (MGUS) or multiple myeloma (MM) in patients with Ph-negative myeloproliferative neoplasms (MPN), but few cohorts of patients have been published. This study concerns 667 patients newly diagnosed with polycythemia vera (PV) or essential thrombocythemia (ET) who were tested for monoclonal (M) protein at diagnosis (13.9% of patients). The overall survival of patients with M protein was dramatically lower than that of patients without M protein (12.7 versus 22.4 years; p = .0132). Univariate analysis identified the presence of M protein as a potential risk factor for the secondary occurrence of myelofibrosis (p = .02), myelodysplastic syndrome (p = .043), and MM/Waldenstrom macroglobulinemia (p < .0001). Our cohort shows that the presence of M proteins in patients with PV or ET leads to a poor prognosis. We believe that testing for M protein could help practicians to identify such patients.

Pathophysiological Study of Sensitive Skin.

Sensitive skin is a clinical syndrome characterized by the occurrence of unpleasant sensations, such as pruritus, burning or pain, in response to various factors, including skincare products, water, cold, heat, or other physical and/or chemical factors. Although these symptoms suggest inflammation and the activation of peripheral innervation, the pathophysiogeny of sensitive skin remains unknown. We systematically analysed cutaneous biopsies from 50 healthy women with non-sensitive or sensitive skin and demonstrated that the intraepidermal nerve fibre density, especially that of peptidergic C-fibres, was lower in the sensitive skin group. These fibres are involved in pain, itching and temperature perception, and their degeneration may promote allodynia and similar symptoms. These results suggest that the pathophysiology of skin sensitivity resembles that of neuropathic pruritus within the context of small fibre neuropathy, and that environmental factors may alter skin innervation.

Diagnostic Algorithm for Glycogenoses and Myoadenylate Deaminase Deficiency Based on Exercise Testing Parameters: A Prospective Study.

AIM: Our aim was to evaluate the accuracy of aerobic exercise testing to diagnose metabolic myopathies. METHODS: From December 2008 to September 2012, all the consecutive patients that underwent both metabolic exercise testing and a muscle biopsy were prospectively enrolled. Subjects performed an incremental and maximal exercise testing on a cycle ergometer. Lactate, pyruvate, and ammonia concentrations were determined from venous blood samples drawn at rest, during exercise (50% predicted maximal power, peak exercise), and recovery (2, 5, 10, and 15 min). Biopsies from vastus lateralis or deltoid muscles were analysed using standard techniques (reference test). Myoadenylate deaminase (MAD) activity was determined using p-nitro blue tetrazolium staining in muscle cryostat sections. Glycogen storage was assessed using periodic acid-Schiff staining. The diagnostic accuracy of plasma metabolite levels to identify absent and decreased MAD activity was assessed using Receiver Operating Characteristic (ROC) curve analysis. RESULTS: The study involved 51 patients. Omitting patients with glycogenoses (n = 3), MAD staining was absent in 5, decreased in 6, and normal in 37 subjects. Lactate/pyruvate at the 10th minute of recovery provided the greatest area under the ROC curves (AUC, 0.893 ± 0.067) to differentiate Abnormal from Normal MAD activity. The lactate/rest ratio at the 10th minute of recovery from exercise displayed the best AUC (1.0) for discriminating between Decreased and Absent MAD activities. The resulting decision tree achieved a diagnostic accuracy of 86.3%. CONCLUSION: The present algorithm provides a non-invasive test to accurately predict absent and decreased MAD activity, facilitating the selection of patients for muscle biopsy and target appropriate histochemical analysis.

[Pseudohypobicarbonatemia in a patient with a kappa IgA monoclonal gammapathy]. / Pseudohypobicarbonatémie chez une patiente atteinte d'une gammapathie monoclonale à IgA kappa.

Paraprotein interferences assays are known but rather unusual in clinical chemistry.we here report a paraprotein interference with a bicarbonate assay in a IgA kappa-type myeloma patient. Serum bicarbonate level was assessed by the enzymatic method of a multiparametric chemistry analyzer (Advia 1800, Siemens) as well as a specific electrode assay on a blood gas analyzer (GEM 4000, IL). Paraprotein interference with the enzymatic assay was evidenced by an abnomally low bicarbonate level measured by the enzymatic method in contrast with usual levels obtained by using the gas analyzer and with the clinical status of the patient. Therefore, gammapathy has to be taken into consideration when interpreting biological data.

The hook effect in calcitonin immunoradiometric assay: a case report.

UNLABELLED: The hook effect, which has long been detected and documented for immunoradiometric assays (IRMA) such as those measuring prolactin or thyroglobulin, occurs when the serum antigen level is extremely high, thus inducing a bias in the methodology of measurement. RESULTS: We report the case of an 80-year-old man with confirmed medullary thyroid carcinoma (MTC). In the case reported here, the clinical status of the patient contrasts with his tumor antigen, serum calcitonin (CT), concentrations. The measured increased CT concentrations revealed the presence of a hook effect. This phenomenon occurs due to an excess of antigen during the one-step IRMA where the signal antibodies, bound to the non-captured antigens, are washed out during the measurement, inducing the loss of signal. Aiming to prevent the "hook effect", successive dilutions of the same sample of serum were done. CONCLUSIONS: Previous studies have shown when one-step IRMA reveals high concentrations of a tumor serum antigen (i.e. prolactin or thyroglobulin), a two-step IRMA or a systematic 1:10 dilution of the serum sample prevents the formation of the "hook effect". In our case report, the CT "hook effect" formation was prevented by performing serial dilutions of the serum sample.

Isolation of a new cell population in the glioblastoma microenvironment.

Glioblastoma (GB) is a highly infiltrative tumor recurring in 90% of cases within a few centimeters of the resection cavity, even in cases of complete tumor resection and adjuvant chemo/radiotherapy. This observation highlights the importance of understanding this special zone of brain tissue surrounding the tumor. It is becoming clear that the nonneoplastic stromal compartment of most solid cancers plays an active role in tumor proliferation, invasion, and metastasis. Very little information, other than that concerning angiogenesis and immune cells, has been collected for stromal cells from GB. As part of a translational research program, we have isolated a new stromal cell population surrounding GB by computer-guided stereotaxic biopsies and primary culture. We named these cells GB-associated stromal cells (GASCs). GASCs are diploid, do not display the genomic alterations typical of GB cells, and have phenotypic and functional properties in common with the cancer-associated fibroblasts (CAFs) described in the stroma of carcinomas. In particular, GASCs express markers associated with CAFs such as fibroblast surface protein, alpha-smooth muscle actin (α-SMA), and platelet-derived growth factor receptor-beta (PDGFRß). Furthermore, GASCs have a molecular expression profile different from that of control stromal cells derived from non-GB peripheral brain tissues. GASCs were also found to have tumor-promoting effects on glioma cells in vitro and in vivo. The isolation of GASCs in a tumor of neuroepithelial origin was unexpected, and further studies are required to determine their potential as a target for antiglioma treatment.

[Significance of 3-methoxytyramine urine measurement in the diagnosis of pheochromocytomas and paragangliomas: about 28 patients]. / Intérêt du dosage urinaire de la 3-méthoxytyramine dans le diagnostic des phéochromocytomes et paragangliomes: à propos de 28 cas.

Measurement of catecholamines derivatives is used to diagnose tumors such as pheochromocytomas and paragangliomas. Despite the low incidence of these diseases, their diagnosis is essential because of potentially lethal episodes of malignant hypertension related to an inappropriate secretion of catecholamines by these tumors. The catecholamines derivatives include 3-methoxytyramine, normetanephrine and metanephrine, assayed in urine or plasma. The significance of the measurement of urinary 3-methoxytyramine was addressed by analysing the records of 28 patients aged 25 to 84 years with isolated elevation of this derivative, with non-pathological urinary rates of metanephrine and normetanephrine, that might help suspect a catecholamine inappropriate secretion. In these situations, no pheochromocytoma or paraganglioma was diagnosed. This study, after discussing possible biases in the clinical care and diagnosis approach of these patients, raises the question of the relevance of this assay in the diagnostic management of these diseases.

Acute renal dysfunction after cardiac surgery with cardiopulmonary bypass is associated with plasmatic IL6 increase.

BACKGROUND: Acute renal dysfunction (ARD) is common after cardiac surgery with cardiopulmonary bypass (CPB). CPB results in a sudden systemic inflammatory response. Systemic and local pro-inflammatory cytokines synthesis has been linked with sub-clinical renal injury, especially tubular lesions. Therefore, we sought to assess the systemic synthesis pro-inflammatory cytokines and its association with perioperative ARD after cardiac surgery with CPB. METHODS: Sixty-two patients undergoing cardiac surgery with CPB were prospectively included. Four groups of patients were defined according to blood creatinine increase: no ARD (less than 25% increase), faint ARD (25-50% increase), moderate ARD (50-100% increase), severe ARD (more than 100% increase). RESULTS: Within the 48 post-operative hours was ARD observed as no dysfunction (41.9%), faint (32.2%), moderate (16.1%), severe (9.6%). One patient had to undergo a dialysis. Pre-operative characteristics were homogenous between the four groups excepted the left ventricle ejection fraction. ARD was associated with a low urinary output with high sodium excretion fraction. Significant increase of IL-6 level occurred when patients underwent a severe ARD despite no significant differences for the CRP and TNF-alpha concentrations. CONCLUSION: Severe acute renal dysfunction after cardiac surgery with CPB is associated with a significant increased IL-6 systemic production.