Systematic review and quality analysis of emerging diagnostic measures for calcium pyrophosphate crystal deposition disease

Calcium pyrophosphate deposition disease: historical overview and potential gaps

CPPD disease can affect patients’ quality of life through its various clinical presentations. This mini-review discusses the evolution of CPPD from its discovery to current knowledge of its pathogenesis, genetic associations, diagnostics, and treatment options. Despite extensive research, the exact mechanisms of CPPD are not well understood, and there is a notable lack of knowledge about psychosocial impacts and patient experiences. This study aims to present a CPPD Disease Timeline identifying gaps in current knowledge and potential directions for future research. These findings contribute to a broader understanding of CPPD disease and emphasize the importance of continued research and innovation in this field.

High prevalence of chondrocalcinosis and frequent comorbidity with calcium pyrophosphate deposition disease in patients with seronegative rheumatoid arthritis

Background

The crystal-induced calcium pyrophosphate deposition disease (CPPD) clinically appearing as pseudogout differs from the mere radiographic finding of chondrocalcinosis (CC) but may cause symptoms resembling rheumatoid arthritis (RA).

Objective

To study the prevalence of CPPD and CC in rheumatic diseases focusing on differences between seropositive and seronegative RA.

Patients and methods

In a retrospective study design, we analysed records and radiographs of consecutive new patients presenting to our centre between January 2017 and May 2020. 503 patients were identified based on expert diagnoses: 181 with CPPD, 262 with RA, 142 seropositive (54.2%) and 120 seronegative RA, gout (n=30) and polymyalgia rheumatica (n=30), mean symptom duration <1 year in almost all patients.

Results

The majority of patients had only one rheumatological diagnosis (86.9%). Most patients with CPPD (92.6%) had radiographic CC, primarily in the wrists. The prevalence of CC was higher in seronegative (32.3%) than in seropositive RA (16.6%), respectively (p<0.001). Patients with CPPD were older (p<0.001) and had acute attacks more frequently than patients with RA (p<0.001), who had symmetric arthritis more often (p=0.007). The distribution pattern of osteoarthritic changes in radiographs of hands and wrists differs between patients with RA and CPPD. CC was present in more than one joint in 73.3% of patients with CPPD, 9.6% with seropositive and 18.7% with seronegative RA.

Discussion

CPPD and CC were more frequent in seronegative versus seropositive RA. Symmetry of arthritis and acuteness of attacks differentiated best between CPPD and RA but localisation of joint involvement did not. Co-occurrence of both diseases was frequently observed.

The diagnostic value of conventional radiography and musculoskeletal ultrasonography in calcium pyrophosphate deposition disease: a systematic literature review and meta-analysis

OBJECTIVE

To examine and compare the accuracy of conventional radiography (CR) and musculoskeletal ultrasonography (US) in the diagnosis of calcium pyrophosphate (CPP) crystals deposition disease (CPPD).

DESIGN

A systematic search of electronic databases (PubMed, Embase, and Cochrane), conference abstracts and reference lists was undertaken. Studies which evaluated the accuracy of CR and/or US in the diagnosis of CPPD, using synovial fluid analysis (SFA), histology or classification criteria as reference tests were included. Subgroup analyses by anatomic site and by reference test were performed.

RESULTS

Twenty-six studies were included. Using SFA/histology as reference test, CR and US showed an excellent (CR AUC = 0.889, 95%CI = 0.811-0.967) and an outstanding (US AUC = 0.954, 95%CI = 0.907-1.0) diagnostic accuracy (p < 0.01), respectively. Furthermore, US showed a higher sensitivity (0.85, 95%CI = 0.79-0.90 vs 0.47, 95%CI = 0.40-0.55) and only a little lower specificity (0.87, 95%CI = 0.83-0.91 vs 0.95, 95%CI = 0.92-0.97) than CR. A considerable heterogeneity between the studies was found, with adopted reference test being the main source of heterogeneity. In fact, subgroup analysis showed a significant change in the diagnostic accuracy of CR, but not of US, using Ryan and McCarty criteria or SFA/histology as reference test (CR: AUC = 0.956, 95%CI = 0.925-1.0 vs AUC = 0.889, 95%CI = 0.828-0.950, respectively, p < 0.01) (US: AUC = 0.922, 95%CI = 0.842-1.0 vs AUC = 0.957, 95%CI = 0.865-1.0, respectively, p = 0.08) CONCLUSIONS: Although US is more sensitive and a little less specific than CR for identifying CPP crystals, both these two techniques showed a great diagnostic accuracy and should be regarded as complementary to each other in the diagnostic work-up of patients with CPPD.

Sonographic assessment of calcium pyrophosphate deposition disease at wrist. A focus on the dorsal scapho-lunate ligament

OBJECTIVES

To investigate the diagnostic accuracy of ultrasound and conventional radiography in the evaluation of calcium pyrophosphate crystal deposits at wrist level.

METHODS

Consecutive patients with a "definite" diagnosis of calcium pyrophosphate deposition disease and disease-controls were prospectively included in this cross-sectional single-centre study. Scapho-lunate ligament, triangular fibrocartilage complex, and volar recess of the radio-lunate joint were explored using ultrasound, conventional radiography and computed tomography.

RESULTS

Sixty one patients and 39 disease controls were enrolled. Two-hundred wrists were evaluated using both conventional radiography and ultrasound and 26 using computed tomography. Ultrasound findings indicative of crystal deposits were found in at least one wrist in 95.1% of patients and in 15.4% of controls (P<0.001). Scapho-lunate ligament calcifications were reported in 83.6% of patients and in 5.1% of controls (P<0.001). On conventional radiography, calcifications were found in at least one wrist in 72.1% of patients and in 0% of controls (P<0.001). Using the Ryan-McCarty criteria as a gold standard, sensitivity, specificity and diagnostic accuracy were 0.72 (0.59-0.83), 1.0 (0.91-1.0) and 0.83 (0.74-0.90) for conventional radiography and 0.95 (0.86-0.99), 0.85 (0.69-0.94) and 0.91 (0.84-0.96) for ultrasound. The agreement between ultrasound and computed tomography was substantial when assessing triangular fibrocartilage complex (kappa=0.70; 0.43-0.97) and scapho-lunate ligament (kappa=0.69; 0.41-0.97), and moderate for radio-lunate joint (kappa=0.46; 0.12-0.80).

CONCLUSIONS

This study supports the diagnostic accuracy of ultrasound in evaluating wrist involvement in calcium pyrophosphate deposition disease. The inclusion of the scapho-lunate ligament in a disease-oriented scanning protocol could improve the diagnostic performance of ultrasound.

Diagnostic advances in synovial fluid analysis and radiographic identification for crystalline arthritis

PURPOSE OF REVIEW

The present review addresses diagnostic methods for crystalline arthritis including synovial fluid analysis, ultrasound, and dual energy CT scan (DECT).

RECENT FINDINGS

There are new technologies on the horizon to improve the ease, sensitivity, and specificity of synovial fluid analysis. Raman spectroscopy uses the spectral signature that results from a material's unique energy absorption and scatter for crystal identification. Lens-free microscopy directly images synovial fluid aspirate on to a complementary metal-oxide semiconductor chip, providing a high-resolution, wide field of view (∼20 mm) image. Raman spectroscopy and lens-free microscopy may provide additional benefit over compensated polarized light microscopy synovial fluid analysis by quantifying crystal density in synovial fluid samples. Ultrasound and DECT have good sensitivity and specificity for the identification of monosodium urate (MSU) and calcium pyrophosphate (CPP) crystals. However, both have limitations in patients with recent onset gout and low urate burdens.

SUMMARY

New technologies promise improved methods for detection of MSU and CPP crystals. At this time, limitations of these technologies do not replace the need for synovial fluid aspiration for confirmation of crystal detection. None of these technologies address the often concomitant indication to rule out infectious arthritis.

Review: Unmet Needs and the Path Forward in Joint Disease Associated With Calcium Pyrophosphate Crystal Deposition

Calcium pyrophosphate (CPP) crystal deposition (CPPD) is prevalent and can be associated with synovitis and joint damage. The population of elderly persons predominantly affected by CPPD is growing rapidly. Since shortfalls exist in many aspects of CPPD, we conducted an anonymous survey of CPPD unmet needs, prioritized by experts from the Gout, Hyperuricemia and Crystal-Associated Disease Network. We provide our perspectives on the survey results, and we propose several CPPD basic and clinical translational research pathways. Chondrocyte and cartilage culture systems for generating CPP crystals in vitro and transgenic small animal CPPD models are needed to better define CPPD mechanism paradigms and help guide new therapies. CPPD recognition, clinical research, and care would be improved by international consensus on CPPD nomenclature and disease phenotype classification, better exploitation of advanced imaging, and pragmatic new point-of-care crystal analytic approaches for detecting CPP crystals. Clinical impacts of CPP crystals in osteoarthritis and in asymptomatic joints in elderly persons remain major unanswered questions that are rendered more difficult by current inability to therapeutically limit or dissolve the crystal deposits and assess the consequent clinical outcome. Going forward, CPPD clinical research studies should define clinical settings in which articular CPPD does substantial harm and should include analyses of diverse clinical phenotypes and populations. Clinical trials should identify the best therapeutic targets to limit CPP crystal deposition and associated inflammation and should include assessment of intraarticular agents. Our perspective is that such advances in basic and clinical science in CPPD are now within reach and can lead to better treatments for this disorder.

Ultrasound verified inflammation and structural damage in patients with hereditary haemochromatosis-related arthropathy

Background

Chronic arthropathy occurs in approximately two thirds of patients with hereditary haemochromatosis (HH). The aim was to study inflammatory and structural lesions in patients with HH with (HH-A) and without arthropathy (HH-WA) using ultrasonography.

Methods

This was a cross-sectional study of 26 patients with HH-A, 24 with HH-WA and 37 with hand osteoarthritis (HOA). Clinical examination was performed in 68 joints, and we retrieved data on hand function, pain and global disease activity (all using a visual analogue scale (VAS)), morning stiffness and ferritin levels. Standard x-ray and ultrasound were conducted in 36 joints (hands, hips, knees and ankles), and we graded grey scale synovitis (GSS), power Doppler ultrasound (PD), osteophytes, erosions, tenosynovitis and cartilage damage semi-quantitatively in accordance with prior publications.

Results

Ultrasound revealed a high proportion of inflammatory changes in HH-A; GSS was found in 96.2% and PD signals in 80.8% of patients (median GSS score 9, PD score 2.5). The frequency of these findings was similar in HOA. Inflammation was also common in HH-WA, yielding GSS in 83.3% and PD signals in 50.0% of patients. Cartilage damage was most prominent in HH-A as compared to HH-WA and HOA (median scores 11.0, 2.5 and 2.0, respectively). The prevalence and extent of erosions and osteophytes were similar in all groups. None of the ultrasound scores was associated with pain or function; GSS, PD, osteophyte and cartilage scores correlated with x-ray-verified structural damage.

Conclusion

A high prevalence of ultrasound-verified inflammation and cartilage damage was found in HH-A, and to a lesser extent in HH-WA. These findings were associated with x-ray-verified damage but not with clinical scores of pain and function.