Sensory neuropathies often involve small-diameter myelinated and unmyelinated nerve fibers, and neurologic and electrophysiologic findings may be normal unless larger nerve fibers are involved. The ...small (intra)epidermal nerve fibers (ENFs) now can be visualized with immunohistochemical techniques using the panaxonal marker anti-protein gene product 9.5 (PGP 9.5). Using this technique, the authors have established a reference range for ENF in a healthy white population and evaluated the reliability of the method.
Two punch biopsies, 3 mm in diameter, were taken from the distal part of the leg in 106 healthy volunteers (mean age, 49.0 +/- 19.6 years). Fifty-micrometer frozen thick sections were incubated with rabbit polyclonal antibodies to human PGP 9.5. The number of ENF/mm then was reported as the mean of counts in six sections (three sections from each of the two biopsies).
The mean number of ENFs was 12.4 +/- 4.6 mm. In a multiple regression model, the density of ENF depended on age and gender (Y = 13.92 + 2.25 (gender) - 0.06 x age). The mean difference in ENF by intraobserver analysis was 0.2 +/- 1.2 ENF/mm, and by interobserver analysis, it was 0.4 +/- 1.5 fibers/mm.
Normal means and ranges for the density of epidermal nerve fibers in a reference population have been established. The density of epidermal nerve fibers decreases with age and is lower in men compared with women. Intraobserver and interobserver analysis proves the reliability of the method.
Objective To evaluate sensitivity of quantitative sensory testing (QST) and skin biopsy with assessment of intraepidermal nerve fiber density (IENFD) in patients with symptoms and clinical findings ...of small fiber neuropathy (SFN). Methods This is a retrospective study on 179 patients (age 48.7 ± 14.0 (8–82 years old), 64 men, 115 woman) examined from January 2012 to March 2015. All patients underwent nerve conduction studies (NCS), QST and skin biopsy for assessment of IENFD. Results NCS were normal in 85% of patients. Mean IENFD in the total patient group was 6.1 ± 2.7 fibers per mm (0.9–17.0). 94 patients (52%) had reduced IENFD. 82 patients (46%) had abnormalities on QST (in 2 and more parameters). However, only 43 patients (24%) had both abnormalities on QST and reduced IENFD. There were normal findings on both QST and IENFD in 29 patients (16%). Conclusions There is a rather lower concordance between the results of QST and IENFD. It remains unclear if diagnosis of SFN can be excluded in cases of normal findings both on QST and skin biopsy. Key message Both skin biopsy and QST should be performed in patients with suspected SFN.
Small diameter nerve fibre (SDNF) neuropathy is an axonal sensory neuropathy affecting unmyelinated (C) and thin myelinated (A‐delta) fibres. We have evaluated 75 patients with symptoms and signs ...suggesting SDNF dysfunction with or without symptoms and signs of co‐existing large diameter nerve fibre involvement. The patients were examined clinically and underwent skin biopsy, quantitative sensory testing (QST) and nerve conduction studies (NCS). The purpose of this study was to compare the relationship between the different methods and in particular measurements of thermal thresholds and intraepidermal nerve fibre (IENF) density in the same site of the distal leg. The main subdivision of the patient material was made according to the overall NCS pattern. Patients with normal NCS (38) had 6.4 ± 3.8 and patients with abnormal NCS (37) had 4.4 ± 3.4 IENF per mm (P = 0.02). Limen (difference between warm and cold perception thresholds) was significantly higher (more abnormal) in those with abnormal than in those with normal NCS (22.1 ± 9.1 vs. 13.4 ± 5.6, P < 0.0001). Cold perception threshold was more abnormal (P < 0.0001) than warm perception threshold (P = 0.002). Correlation between IENF and QST was statistically significant only when NCS was abnormal, and thus dependent of a more severe neuropathic process in SDNFs.
To investigate if there is a correlation between clinical expression (duration of disease, age, walking function) and morphological alterations in affected muscle (structural changes, ...immunohistochemical and the level of alpha-DG glycosylation) among 25 patients with Limb Girdle Muscular Dystrophy type 2I (LGMD2I) all with the common C.826C>A mutation ). Muscle biopsies were obtained from 25 patients. Quantitative evaluation of morphological alterations in muscle sections, and immunohistochemistry (IHC) with antibodies directed against the alpha-dystroglycan glycan epitope, was performed by light microscopy. A semi-quantitative assessment of changes was recorded, point-graded and summarized as morphological sum-score for each biopsy.. Western blot (WB) analysis on muscle biopsy homogenates were carried with antibodies directed towards the core alpha-DG as well as the alpha-DG-glycan epitope. Laminin overlay was included. Muscle biopsies from 25 patients with LGMD2I presented large variation in morphological features. All biopsies presented reduced molecular weight of alpha-DG as detected with alpha-DG core antibody on WB analysis. Immunohistochemistry and WB analysis directed towards the alpha-DG-glycan epitope, as well as laminin overlay, demonstrated large variation in signal intensity among the LGMD2I patients. Results from IHC and WB/laminin overlay correlated poorly. There was no obvious correlation between ages at onset or duration of disease at biopsy versus the level of alpha-DG glycosylation. Likewise, there was no apparent association between severities of disease and the sum-scores of structural changes in the muscle biopsies. The clinical and morphological variability seen among LGMD2I patients with identical FKRP genotype must therefore be explained by other genetic or environmental mechanisms.
To assess potential correlation of severity of Limb Girdle Muscular Dystrophy type 2I (LGMD2I) with morphological, immunohistochemical and immunoblot alterations, in muscle biopsies from 27 patients ...with (LGMD2I). Mutations in the FKRP (Fukutin Related Protein) gene produce a range of clinical phenotypes including Limb Girdle Muscular Dystrophy Type 2I (LGMD2I), which belong to the mild end of the clinical spectrum. Seven different FKRP mutations have been detected among Norwegian LGMD2I patients of whom the majority were homozygous for the common c.826C>A mutation, and presented with a milder phenotype. Muscle biopsies were obtained from 27 patients. Quantitative evaluation of morphological alterations in muscle cross- sections, and immunohistochemistry (IHC) with antibodies directed against the alpha-dystroglycan epitope, was performed by light microscopy. A semi-quantitative assessment of changes was recorded, point-graded and summarized as morphological sum-score for each biopsy. The following myopathic changes were graded in the scoring system: fibrosis, regeneration, atrophy, centralized nuclei, necrosis, and inflammation. Western blot (WB) analysis on muscle biopsy homogenates were carried with antibodies directed towards the core alpha-DG as well as the alpha-DG epitope. Muscle biopsies from 27 patients with LGMD2I presented large variation in morphological features (Table 1).
Aim: To investigate the difference between physiological and pathological cardiac remodelling induced, respectively, by pregnancy and angiotensin (Ang) II, and to test the hypothesis that pregnancy ...protects against Ang II effects. Methods: Female Wistar rats, pregnant (n = 12) and non-pregnant (n = 12), were implanted with mini-pumps containing saline (sham) or 150 ng kg⁻¹ min⁻¹ Ang II. Ten days later echocardiography and blood pressure measurement were performed. Expression of 22 genes was assessed using RT-PCR. Microscopic sections of LV were prepared to determine collagen content (Sirius Red staining), vessel density (β-actin immunolabelling) and myocytes diameter (Toluidine Blue). Results: Heart weight (HW) was increased in Ang II treated groups compared with their controls. Furthermore, HW of Ang II treated pregnant rats (1.0 ± 0.03 g) was higher than that in non-pregnant sham (0.7 ± 0.02 g), pregnant (0.8 ± 0.01 g) and Ang II treated non-pregnant (0.8 ± 0.02 g) rats. Relative LV wall thickness showed similar pattern. Aortic pressure was significantly increased in Ang II groups. Collagen content was increased in Ang II (4.0 ± 0.5%) compared with sham (1.5 ± 0.1%) but reduced again when treated rats were pregnant (2.8 ± 0.4%). Vessel density was reduced by 47.8% after Ang II treatment in non-pregnant and by only 13.9% in pregnant rats. Gene expression analysis showed increased expression of atrial natriuretic factor (ANF), brain natriuretic peptide (BNP), anykrin repeat domain-containing protein 1 (Ankrd-1), protein kinase C-α and -δ and tumour suppressor gene TP53 (p53) in Ang II treated groups and upregulation of ANF, BNP and Ankrd-1 remained when pregnancy was combined with Ang II. Pregnancy reduced expression of: α-myosin heavy chain, tumour necrosis factor-α, p53, endothelial nitric oxide synthase and inducible nitric oxide synthase. Conclusion: Pregnancy seems to counteract the detrimental effects of Ang II on fibrosis and angiogenesis in heart. In addition, pregnancy and Ang II lead to partly opposite changes in the expression of some genes important for heart function.
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