Computer based quantitative analysis of capillary abnormalities in systemic sclerosis and its relation to plasma concentration of von Willebrand factor

Quantitative nailfold capillaroscopy-update and possible next steps

We review the exciting potential (and challenges) of quantitative nailfold capillaroscopy, focusing on its role in systemic sclerosis. Quantifying abnormality, including automated analysis of nailfold images, overcomes the subjectivity of qualitative/descriptive image interpretation. First we consider the rationale for quantitative analysis, including the potential for precise discrimination between normal and abnormal capillaries and for reliable measurement of disease progression and treatment response. We discuss nailfold image acquisition and interpretation, and describe how early work on semi-quantitative and quantitative analysis paved the way for semi-automated and automated analysis. Measurement of red blood cell velocity is described briefly. Finally we give a personal view on 'next steps'. From a clinical perspective, increased uptake of nailfold capillaroscopy by general rheumatologists could be achieved via low-cost hand-held devices with cloud-based automated analysis. From a research perspective, automated analysis could facilitate large-scale prospective studies using capillaroscopic parameters as possible biomarkers of systemic sclerosis-spectrum disorders.

Use of artificial intelligence in imaging in rheumatology - current status and future perspectives

After decades of basic research with many setbacks, artificial intelligence (AI) has recently obtained significant breakthroughs, enabling computer programs to outperform human interpretation of medical images in very specific areas. After this shock wave that probably exceeds the impact of the first AI victory of defeating the world chess champion in 1997, some reflection may be appropriate on the consequences for clinical imaging in rheumatology. In this narrative review, a short explanation is given about the various AI techniques, including 'deep learning', and how these have been applied to rheumatological imaging, focussing on rheumatoid arthritis and systemic sclerosis as examples. By discussing the principle limitations of AI and deep learning, this review aims to give insight into possible future perspectives of AI applications in rheumatology.

Computed tomography-guided sub-end plate injection of pingyangmycin for a novel rabbit model of slowly progressive disc degeneration

BACKGROUND CONTEXT

Different animal models are used in disc degenerative disease research by now. To our knowledge, a functional animal model that mimics ischemic and slowly progressive disc degeneration of humans does not exist.

STUDY DESIGN

This is an experimental animal study of disc degeneration.

PURPOSE

The purpose of this study was to establish an ischemic and slowly progressive intervertebral disc (IVD) degeneration model with an injection of pingyangmycin (PYM) into subchondral bone adjacent to the disc, using bone marrow needle guided by computed tomography (CT) scan.

METHODS

The subchondral bone adjacent to the lumbar IVDs (from L3-L4 to L5-L6) of 18 rabbits was randomly injected with 3 mL PYM solution (1.5 mg/mL PYM), 3 mL phosphate-buffered saline (vehicle control), or exteriorized but not injected with anything (sham), with using bone marrow needle guided by CT scan. The degenerative process was investigated by using radiography and magnetic resonance imaging at 1, 3, and 6 months postoperatively, combined with histological scoring, immunohistochemistry, and real-time polymerase chain reaction analysis.

RESULTS

Significant disc space narrowing was observed at 6 months in the discs adjacent to the subchondral bone injected with PYM, compared with the control groups (p<.05). The magnetic resonance imaging assessment also demonstrated a progressive loss of T2-weighted signal intensity postoperatively. The histological score increased significantly compared with that of the control groups from 3 months to the end point (p<.05). The bone tissue area of the end plate increased significantly at the end point, compared with that of the control groups (p<.05). The results of molecular analysis showed significant increase of matrix metalloproteinase-3, a disintegrin and metalloproteinase with thrombospondin motif-5, and marked reduction of aggrecan and Type II collagen after 3 months at the messenger RNA levels in the discs of PYM group (p<.05). The von Willebrand factor expression of PYM group also showed a significant reduction after 1 month (p<.05).

CONCLUSIONS

Percutaneous injection of PYM into the subchondral bone adjacent to the lumbar IVDs of rabbits, using bone marrow needle guided by CT scan, can result in ischemic and slowly progressive disc degeneration model, which mimics the onset of human disc degeneration.

The emerging application of semi-quantitative and quantitative capillaroscopy in systemic sclerosis

Systemic sclerosis (SSc) is a connective tissue disease with high morbidity and mortality, characterized by autoimmunity, obliterative vasculopathy involving mainly the microvasculature, and fibrosis. SSc-specific nailfold capillaroscopic changes have been defined, and nailfold capillaroscopy (NFC) is now unequivocally accepted to be a cornerstone for the early diagnosis of SSc. However, the use of NFC in patients already diagnosed with SSc is still not standardized. Several studies have shown that NFC abnormalities correlate with disease activity and severity and are predictive for disease worsening, such as occurrence of new digital ulcers. More importantly, successful treatment has been shown to diminish NFC abnormalities in severe SSc cases. These findings support the importance of NFC in monitoring patients with SSc and even its role as an outcome measure in SSc clinical trials. It is a matter of debate if Semi-quantitative and Quantitative NFC would be a more sensitive tool than qualitative NFC for meeting these objectives. This review is presenting the emerging application of Semi-quantitative and Quantitative NFC in SSc and its potential benefits.

Assessment of serum vascular endothelial growth factor and nail fold capillaroscopy changes in systemic lupus erythematosus with and without cutaneous manifestations

Angiogenesis and microvascular endothelial injury play a role in the pathogenesis of systemic lupus erythematosus (SLE). Vascular endothelial growth factor (VEGF), a key regulator of angiogenesis, and nail fold capillaroscopy (NFC) have been investigated in few studies in SLE with no reports targeting SLE with cutaneous manifestations. To evaluate NFC changes and VEGF serum level in relation to disease activity in SLE patients with versus without cutaneous manifestations. Thirty SLE patients (15 with cutaneous manifestations [group I], 15 without [group II]) and 15 healthy controls were evaluated for VEGF serum levels, NFC changes and were related to disease activity. VEGF serum levels were significantly higher in patients than controls (median and interquartile range [IQR]: 2110.77, 471.09-4714.30 vs. 60.00, 14-366, respectively, P < 0.0001). VEGF cut-off value to predict SLE patients was more than 293 and to detect moderate and severe SLE activity was more than 422 pg/mL and more than 3800 pg/mL, respectively. Serum VEGF levels increased with increased disease activity (P < 0.05). It was significantly higher in group I than group II (median and IQR: 2624.74, 1801.39-4141.70 vs. 862.50, 180-2426.95, respectively, P < 0.05). Mean serum VEGF was significantly higher with NFC score 3 than 1 (P = 0.008). NFC score and SLE activity were significantly associated in patients (P < 0.05). Serum VEGF is significantly elevated in SLE patients with cutaneous manifestations and its cut-off values to detect different activity grades of SLE are identified. Abnormalities in NFC reflect the extent of microvascular involvement in SLE.

Laser preconditioning on cranial bone site: analysis of morphological vascular parameters

BACKGROUND AND OBJECTIVES

Bone vascularization is a key factor in the bone healing process following X-ray irradiation. Preserving the vascular network from X-ray-induced injury is a relevant approach in the promotion of bone healing. Previously, we developed a protocol of laser preconditioning (810 nm diode laser, 36 J/cm²) prior to X-ray radiation (18.75 Gy) which protects the bone vascular network from deleterious effects of X-ray radiation. The aim of this present work is to characterize the effects of laser preconditioning on the bone through a morphological analysis of vascular parameters.

MATERIALS AND METHODS

Digital images of the vascular plexus were taken through an optical bone chamber which was implanted onto the calvaria of rabbits. Bespoke software was used for the quantification of the vessels (classified in four groups according to their diameter), vessel length, and number of nodes at weeks 0, 4, and 8. Twenty rabbits were divided into four groups: control group #1 (n = 5); laser group #2 (n = 5). X-ray radiation group #3 (n = 5), laser preconditioning 24 hours prior to X-ray radiation group #4 (n = 5).

RESULTS

The bone vascular network was stable for groups #1 and #2. Statistical analysis showed a significant reduction of each observed vascular parameter for groups #3 and #4. In the laser preconditioned group #4 the loss was less marked than in the X-ray group #3, especially for large vessels (diameter >50 µm).

DISCUSSION AND CONCLUSION

We provide in vivo microcirculatory evidence to support the concept of laser preconditioning of bone. A computer-based semi-automatic system is described to quantify superficial bone vascular network parameters that had been treated by laser preconditioning prior to X-ray radiation. Laser preconditioning significantly attenuates the deletion of the superficial bone vascular network irradiated by X-ray, especially concerning large diameter vessels.

Capillaroscopic skin ulcer risk index: a new prognostic tool for digital skin ulcer development in systemic sclerosis patients

OBJECTIVE

Digital ulcerations are one of the most frequent manifestations of microangiopathy in patients with systemic sclerosis (SSc; scleroderma). The early detection of SSc patients who are at high risk to develop digital ulcers could allow a preventive treatment of these complications with reduction of morbidity and social costs. The aim of our study was to develop a capillaroscopic skin ulcer risk index (CSURI) that can predict the onset of new digital ulcers by using nailfold videocapillaroscopy (NVC) in patients with SSc.

METHODS

We performed NVC in 120 consecutive unselected patients with SSc (13 men, 107 women, mean +/- SD age 56.1 +/- 13.4 years, mean +/- SD SSc duration 44.7 +/- 60.7 months) to assess the total number of capillaries in the distal row (N), maximum loop diameter (D), number of megacapillaries (M), and the M:N ratio.

RESULTS

Within 3 months since NVC examination, 35 of 120 patients experienced digital ulcers. A significant association between ischemic lesions and the M:N ratio, N, and D was observed; the combination of these parameters allowed us to develop the CSURI, which is characterized by the formula D x M:N(2). A receiver operating characteristic curve analysis showed an area under the curve of 0.926 for ulcer appearance, with specificity and sensitivity of 85.9% and 94.3%, respectively, at the cutoff value of 2.94. Interestingly, 33 of 35 patients with new skin ulcers had a CSURI >2.94, but only 2 of 35 had a CSURI < or =2.94.

CONCLUSION

The proposed CSURI may represent a novel tool with the ability to predict the development of digital ulcers in patients with scleroderma.

Capillaroscopy: questions and answers

Capillaroscopy is an essential imaging technique used in the study of microcirculation and one of the best diagnostic tools for the early detection of systemic sclerosis and related conditions. However, despite the increasing interest in capillary microscopy, there is still a surprising discrepancy between its potential application and its still limited use in rheumatological practice. This contrast is really surprising because few diagnostic techniques can combine all the positive features typical of capillaroscopy (low cost, uninvasiveness, repeatability, high sensitivity, good specificity, easy interpretation of results). The lack of guidelines and recommendations concerning the right way to carry out a correct capillaroscopic examination and the interpretation of the most relevant capillaroscopic abnormalities may represent one of the major drawbacks for its widespread use. Discussion about controversies on this topic should be encouraged, leading to a progressive development of capillaroscopy as a routine investigation in rheumatology.

Nailfold digital capillaroscopy in 447 patients with connective tissue disease and Raynaud's disease

The presence of megacapillaries and a decreased capillary density are the hallmarks of the scleroderma capillary pattern, which can be detected by nailfold capillarmicroscopy. One hundred and eighty-six patients with Raynaud's phenomenon, 65 cases with undifferentiated connective tissue disease (UCTD), 47 patients with systemic lupus erythematosus (SLE), 26 patients with dermato/polymyositis, 14 with rheumatoid arthritis, seven cases with primary Sjögren's syndrome and 102 patients with systemic sclerosis (SSc) were investigated. Of the 16 patients with diffuse cutaneous SSc and the 86 limited cutaneous SSc cases, 14 (87.5%) and 53 (61.6%) showed the scleroderma capillary pattern, respectively. Nine of the 65 (13.8%) cases with UCTD and 24 of the 186 (12.9%) cases with Raynaud's phenomenon also exhibited the same pattern. Four of the 47 (8.5%) with SLE and seven of the 26 (26.9%) with dermato/polymyositis, and no patients with rheumatoid arthritis or Sjögren's syndrome, exhibited the scleroderma capillary pattern. The conclusion is that the scleroderma capillary pattern is often present in SSc and dermato/polymyositis. Furthermore, patients with Raynaud's phenomenon and UCTD may also occasionally exhibit this pattern. Therefore, capillarmicroscopy seems to be a useful tool for the early selection of those patients who are potential candidates for developing scleroderma spectrum disorders.

Daily activities and hand function in women with scleroderma

OBJECTIVE

To give a detailed description of hand function and the ability to perform daily activities among patients with systemic sclerosis.

METHODS

Thirty patients with scleroderma answered a self-administered activities of daily living (ADL) questionnaire. Hand function was estimated with respect to hand mobility, dexterity, and grip force. Perceived symptoms were reported on a visual analogue scale (VAS), and skin thickness was assessed by means of the modified Rodnan skin score.

RESULTS

Finger flexion and extension were the most impaired aspects of hand mobility. Dexterity was on average reduced to 68-80%, and grip force to 46-65% compared with values for healthy persons. The predominant self-perceived problem was Raynaud's phenomenon, whereas pitting scars/ulcers were perceived as the least problem. Activities building on hand and arm function were harder to perform than activities depending on lower limb function. Raynaud's phenomenon, stiffness, grip force, and dexterity were factors with the strongest associations with ADL difficulties. Assistive devices and alternative working methods improved ADL ability.

CONCLUSION

Impaired hand function was related to ADL difficulties and the use of assistive devices improved ADL. This emphasizes the importance of treatments that improve hand function and of testing ergonomic tools.

Nailfold capillary microscopy in healthy children and in childhood rheumatic diseases: a prospective single blind observational study

OBJECTIVES

To develop an objective method of nailfold capillaroscopy (NFC), applicable to a wide age range of paediatric patients. To compare the morphological characteristics of the nailfold capillaries in different rheumatology patient groups and controls.

METHODS

A colour digital video camera attached to a stereomicroscope was used to capture nailfold capillary images. Computerised image processing was used to analyse and store data. Subsequent quantitative and qualitative morphological analysis was performed in the following paediatric patient and control groups: 18 children with connective tissue diseases (CTD: juvenile dermatomyositis, systemic sclerosis, and undifferentiated connective tissue disease), eight with systemic lupus erythematosus, nine with primary Raynaud's disease, three with primary vasculitis, 15 with juvenile idiopathic arthritis, 17 healthy children and 20 healthy adults. Images were analysed by a single assessor who was unaware of the patient details.

RESULTS

The NFC technique was simple to perform and gave reproducible results, although some intra- and intersubject variation was noted. Capillary density and width was age related, with younger children having fewer and wider capillaries than older children and adults. Linear capillary density was significantly higher in healthy adults (mean (SD) 8.6 (1.6) capillaries/mm) compared with healthy children (HC 6.9 (0.9) capillaries/mm). The group with CTD had the most abnormal findings, with lower linear density (4.9 (1.7) capillaries/mm) and increased capillary loop width (10.7 (7.3) mm) compared with HC (3.5 (1.7) mm). In addition, 11/18 (61%) patients in the CTD group had more than two definitely abnormal capillaries in at least two nailfolds, an abnormality not seen in other subjects. Two qualitative measures, the degree of avascularity and general disarrangement of capillary pattern, were more commonly observed in the CTD group than in HC. The proportion of tortuous capillaries did not differ significantly between study groups.

CONCLUSIONS

This study is unique in measuring objective quantitative and qualitative parameters of the nailfold vasculature across a wide spectrum of age and disease. Differences in capillary morphology and frequency in children with CTD compared with other paediatric diseases and healthy controls were demonstrated. In the clinical situation, an assessment of the general degree of disarrangement may offer a fast tool for assessment of the nailfold vasculature which correlates well with NFC data.

Von Willebrand factor propeptide as a marker of disease activity in systemic sclerosis (scleroderma)

In 44 consecutive patients with systemic sclerosis (SSc), plasma concentrations of von Willebrand factor (vWf) were higher than those of the vWf propeptide, but the propeptide showed less variability within patient subgroups. Higher values of the propeptide were observed in patients with early pulmonary involvement. A closer correlation of the propeptide than of vWf to biochemical markers of activity was also evident. Our results suggest that the propeptide, despite a shorter circulating half-time and lower plasma concentrations than vWf, is more useful in the assessment of disease activity in SSc.

Circulating collagen metabolites in systemic sclerosis. Differences between limited and diffuse form and relationship with pulmonary involvement

OBJECTIVE

To study collagen metabolites in systemic sclerosis (SSc) and their relationship with clinical manifestations of the disease.

METHODS

Forty-eight SSc patients, 13 with a diffuse form (dcSSc), 23 with a limited form (lcSSc) and 12 with suspected SSc not fulfilling the ACR criteria, and 31 healthy controls were examined. Serum concentrations of aminoterminal type III procollagen peptide (PIIINP), aminoterminal and carboxyterminal type I procollagen peptides (PINP and PICP) and cross-linked carboxyterminal telopeptide of collagen I (ICTP) were determined by radioimmunoassay.

RESULTS

Increased serum concentrations of ICTP were found in SSc patients compared with controls. Distinctly higher levels of ICTP were observed in dcSSc than in lcSSc. High serum ICTP was correlated with skin score and acute phase reactants, and with reduced pulmonary function. Serum PIIINP concentration was elevated in both lcSSc and dcSSc.

CONCLUSION

Augmented collagen catabolism accompanies the increased collagen synthesis in SSc. Serum ICTP concentration is a marker of this feature and also reflects clinical severity.

Quantitation of microcirculatory abnormalities in patients with primary Raynaud's phenomenon and systemic sclerosis by video capillaroscopy

OBJECTIVE

: To assess nailfold capillary density and dimensions in patients with primary Raynaud's phenomenon (PRP), limited cutaneous systemic sclerosis (LSSc) and diffuse cutaneous SSc (DSSc), and healthy control subjects.

METHODS

: Using the technique of nailfold video capillaroscopy, capillary density and dimensions were averaged from all visible capillaries in a 3 mm length of the nailfold from right and left ring fingers of each subject. Twenty healthy control subjects, 15 patients with PRP, 13 patients with DSSc and 21 patients with LSSc were examined. Intra-observer and inter-observer variability were calculated in 18 and 23 patients, respectively.

RESULTS

: There were significant trends for capillary density to fall and for all dimensions to rise across the four groups (P < 0. 0001 for density and all dimensions, order healthy controls, PRP, DSSc and LSSc). Intra- and inter-observer reproducibility studies showed that although there was good correlation between and within observers, the limits of agreement were between +/-25-50% indicating lack of reproducibility.

CONCLUSIONS

: Microcirculatory abnormalities can be quantified using the technique of video capillaroscopy and were most marked in patients with LSSc.

The predictive value of quantitative nailfold capillary microscopy in patients with undifferentiated connective tissue disease

The present prospective study was undertaken to follow the natural history of patients with Raynaud's phenomenon and to document in these patients the frequency with which secondary disorders develop. Seventeen patients with primary Raynaud's phenomenon (PRP) and 43 patients with undifferentiated connective tissue disease (UCTD) were examined after 6-8 years to see whether they had developed into UCTD or systemic sclerosis (SSc), respectively. Their nailfold capillary parameters were analysed statistically to ascertain whether they would predict for the development of the diseases into UCTD or SSc. Two patients with PRP(12%) developed into UCTD, and 10 patients with UCTD (23%) into SSc. In PRP, all three parameters of the patients who developed into UCTD showed a tendency to be larger than in those who did not develop UCTD. In UCTD, the apical limb width (P < 0.02), capillary width (P < 0.01) and capillary length (P < 0.01) of the subjects who developed SSc were significantly larger than those who did not. Of the clinicolaboratory findings in patients with UCTD, the occurrence rate of abnormal apical limb width (relative risk 20. 7, P < 0.01), abnormal capillary width (relative risk 10.7, P < 0. 01), abnormal capillary length (relative risk 9.2, P < 0.02) and antinuclear antibody (relative risk 9.6, P < 0.05) showed a significant predictive value for the development of UCTD into SSc. These results indicate that quantitative nailfold capillary microscopy, as well as antinuclear antibody, will provide exact predictive information in patients with UCTD in clinical practice.