Overexpression of sonic Hedgehog in the lung mimics the effect of lung injury and compensatory lung growth on pulmonary Sca-1 and CD34 positive cells

Cells localized in the bronchioalveolar duct junction of the murine lung have been identified as potential bronchioalveolar stem cells. Based on the surface marker expression, two main phenotypes have been proposed: Sca-1(+), CD34(+), CD45(-), Pecam(-) and Sca-1(low), CD34(-) CD45(-), Pecam(-) cells. An increase in the number of Sca-1(+), CD34(+) CD45(-), Pecam(-) cells and activation of the sonic hedgehog (Shh) pathway was observed following unilateral pneumonectomy and naphthalene-induced airway injury. Overexpression of Shh in the respiratory tract also resulted in an increase of this cell population. Syngeneic transplantation of beta-galactosidase-expressing bone marrow cells demonstrated that the increase of Sca-1(+), CD34(+), CD45(-), Pecam(-) cells in the lung was a result of local proliferation. Intratracheal administration of purified Shh-stimulated Sca-1(+), CD45(-), Pecam(-) cells coexpressing CD34 to syngeneic mice following pneumonectomy resulted in engraftment of these cells predominantly in the airways for up to 3 months, whereas Sca-1(-), CD45(-), Pecam(-) cells did not engraft. This study suggests that local Sca-1(+), CD34(+), CD45(-), Pecam(-) cells are stimulated during compensatory lung growth, following airway injury and overexpression of Shh and have some potential to engraft in the airways, without showing clonal properties in vivo.

The influence of coil-skull distance on transcranial magnetic stimulation motor-evoked responses

We have investigated the effects of changing the coil-to-skull distance on the motor-evoked responses (MEP) induced with two different magnetic stimulator coils (80 mm round and figure-of-eight coil) at rest and during voluntary muscle contraction. The changes in MEP latency, amplitude and silent period (SP) duration induced by stimulation directly upon the skull, and 1 cm away from the skull were analyzed by computing the probability density distribution (PDD) for the responses obtained from all subjects. This measure corresponds to the finite probability that the event occurs within a given area. Overall, the results were consistent with a distance-induced decrease in magnetic field strength. However, the increase in coil-to-skull distance induced a higher probability of longer latencies in active muscle when stimulating with either coil. Also, stimulating at a distance with the figure-of-eight coil increased the probability of a longer SP duration. The stimulation strength at the two distances was comparable because it was set based on the motor threshold obtained for each distance. Therefore, our results are not entirely compatible with the established exponential drop in magnetic field with increasing distance. Rather, they suggest that a more complex set of interactions occurs in the cortex. The results imply that distinct patterns of cortical network activation may exist related to the distance-induced alterations when the coil is moved away from the skull. Further studies are required to elucidate the precise nature of the distance-related interactions of the magnetic field with the cortex.

[The electrophysiological diagnosis of carpal tunnel syndrome]

Electrophysiological investigations were carried out both in patients with carpal tunnel syndrome (CTS) and in healthy individuals. The evoked potentials were examined during stimulation of sensitive branches of n. medianus and of other nerves. The most sensitive and important for diagnosis appeared to be the electrophysiological test of alteration of responsive reaction to the stimulation of the sensitive branch of n. medianus for 4 finger and the considerable difference of evoked reactions on stimulation of skin palm branch and branch of the 1-st finger of n. medianus. The diagnostic importance of these indices corresponds well to anatomical and pathophysiological characteristics of CTS.

AB0654 IMPACT OF GENDER ON PATIENT PROFILE AND TREATMENT RESPONSE IN ANKYLOSING SPONDYLITIS PATIENTS TREATED WITH TNF-α INHIBITORS

Background:

Ankylosing spondylitis (AS) was historically seen as a predominantly male disease and although recent data showed a more homogenous sex prevalence there is still a long delay and more often a misdiagnosis in women. Also, studies showed that there might be gender-attributable differences regarding clinical characteristics, radiographic damage and response to treatment.

Objectives:

The aim of this study was to assess gender differences in AS patients regarding the clinical presentation, disease activity, functional status and response to tumor necrosis factor-alpha inhibitor (TNF-α inhibitor) therapy.

Methods:

This retrospective analysis included 59 AS patients treated with first TNF-α inhibitor for at least 12 weeks. TNF-α inhibitor therapy introduction and response was determined according to ASAS-EULAR management recommendations for AS. Clinical and demographic parameters were compared between the female and male patients.

Results:

Twenty-four patients (40,68%) were females and 35(59,32%) were males. Women were older than male at moment of study (p=0,049), at the time of diagnosis (p=0,05) and when starting biologic therapy (p=0,009). Moreover, they had a longer diagnosis delay (p=0,017) compared to men. Prevalence of HLA-B27 status and the rate of peripheral arthritis, dactylitis, enthesitis, uveitis or inflammatory bowel disease (IBD) were not different between two groups. Disease activity and functional status were also similar in both groups. Males had a significantly longer drug survival time for first biologic (p=0,031). One female patient (4.2%) and 4 male patients (11,4%) showed primary or secondary inefficacy to TNF-α inhibitor (p=0,61). All 5 non-responders switched to second TNF-α inhibitor and showed a good clinical response. The comparison of the demographic features, clinical characteristics, disease activity, functional status and response to TNF-α inhibitor therapy according to the gender are presented in Table 1.

Conclusion:

In our cohort, the presence of the female gender was related to longer diagnosis delay compared to males. Non-response rate for the first TNF-α inhibitor was similar between groups, but men had longer drug survival time for the first biologic.

References:

[1]Rusman T, van Vollenhoven RF, van der Horst-Bruinsma IE. Gender differences in axial spondyloarthritis: women are not so lucky. Curr. Rheumatol. Rep. 20(6), 35 (2018).

[2]Van der Heijde D, Ramiro S, Landewe R, et al. (2017): 2016 update of the ASAS-EULAR management recommendations for axial spondyloarthritis. Ann Rheum Dis.76:978–91.

Table 1.

Comparison of the baseline demographic, clinical characteristics and treatment response between female and male patients treated with TNF-α inhibitor

female (n=24)male (n=35)P ValueAge (years), mean±SD49,08±12,9442,56±11,960,049Age at onset (years), mean±SD31,6±9,527,7±9,180,117Age at diagnosis (years), mean±SD39,02±11,2233,06±11,360,05Diagnosis delay (years), mean±SD7,39±3,455,36±2,860,017Age at TNF-α inhibitor initiation (years), mean±SD46,4±12,2538,08±11,140,009HLA-B27 positivity n (%)17 (70,8%)32 (91,4%)0,086Family history n (%)10 (41,7%)15 (42,9%)1Peripheral arthritis n (%)16 (66,7%)17 (48,6%)0,26Enthesitis n (%)3 (12,5%)6 (17,1%)0,9Dactylitis n (%)0 (0%)3 (8,6%)0,385Uveitis n (%)8 (33,3%)9 (25,7%)0,732Inflamatory bowel disease n (%)3 (12,5%)5 (14,3%)1BASDAI score at TNF-α inhibitor initiation, mean±SD6,33±1,696,11±1,770,637BASFI score at TNF-α inhibitor initiation, mean±SD5,68±1,396,09±1,390,272ASDAS-CRP score at TNF-α inhibitor initiation, mean±SD3,87±0,933,78±1,020,743Duration of first TNF-α inhibitor use (months), mean±SD35,33±26,6651,54±28,250,031Non-responders to first TNF-α inhibitor n (%)1 (4,2%)4 (11,4%)0,611

Disclosure of Interests:

None declared