Crystal induced arthropathies-a comparative study of 40 patients with apatite rheumatism, chondrocalcinosis and primary synovial chondromatosis

Introduction: Apatite rheumatism (AR), chondrocalcinosis (Ch-C), and primary synovial chondromatosis (prSynCh) are regarded as distinct clinical entities. The introduction of the non-staining technique by Bély and Apáthy (2013) opened a new era in the microscopic diagnosis of crystal induced diseases, allowing the analysis of MSU (monosodium urate monohydrate) HA (calcium hydroxyapatite), CPPD (calcium pyrophosphate dihydrate) crystals, cholesterol, crystalline liquid lipid droplets, and other crystals in unstained sections of conventionally proceeded (aqueous formaldehyde fixed, paraffin-embedded) tissue samples. The aim of this study was to describe the characteristic histology of crystal deposits in AR, Ch-C, and prSynCh with traditional stains and histochemical reactions comparing with unstained tissue sections according to Bély and Apáthy (2013). Patients and methods: Tissue samples of 4 with apatite rheumatism (Milwaukee syndrome), 16 with chondrocalcinosis, and 20 with clinically diagnosed primary synovial chondromatosis were analyzed. Results and conclusion: Apatite rheumatism, chondrocalcinosis, and primary synovial chondromatosis are related metabolic disorders with HA and CPPD depositions. The authors assume that AR and Ch-C are different stages of the same metabolic disorder, which differ from prSynCh in amorphous mineral production, furthermore in the production of chondroid, osteoid and/or bone. prSynCh is a defective variant of HA and CPPD induced metabolic disorders with reduced mineralization capabilities, where the deficient mineralization is replaced by chondroid and/or bone formation. The non-staining technique of Bély and Apáthy proved to be a much more effective method for the demonstration of crystals in metabolic diseases than conventional stains and histochemical reactions.

Calcified Chondroid Mesenchymal Neoplasms

Calcified chondroid mesenchymal neoplasms (CCMN) represent a morphologic spectrum of related tumors. Historically, chondroid matrix or chondroblastoma-like features have been described in soft tissue chondroma, tenosynovial giant cell tumors (especially of the temporomandibular joint (TMJ) region), and in a subset of tophaceous pseudogout. Recently, these tumors have been found to share FN1-receptor tyrosine kinase (RTK) fusions. This review discusses the clinical, morphologic, immunohistochemical, and molecular genetic features of CCMN. The distinction from morphologic mimics is also discussed.

Cartilage calcification is associated with histological degeneration of the knee joint: a highly prevalent, age-independent systemic process

OBJECTIVES

To investigate if cartilage calcification (CC) is a systemic process, the purpose of this study was to determine the prevalence and the amount of meniscal/hyaline CC of the knee joint in the general population by high-resolution imaging (DCR) and to evaluate the association between CC with cartilage degeneration and age.

METHODS

Cross-sectional DCR-study of 180 knee joints of 90 donors (42 female/48 male, mean age 62.3y). Histological hyaline (OARSI) and meniscal (Krenn) cartilage degeneration was determined of all knees.

RESULTS

CC was observed in 100% of the donors (bilaterally in 98%), hyaline cartilage calcification (HCC) in 92% and meniscal calcification (MC) in 100%. CC was detected in more than three out of six distinct cartilage areas in 84.4% of all knees. The mean amount of CC correlated between both sides of donors, the different analyzed areas of the knee joint and between the various types of cartilage structures. There was more calcification in meniscal than in hyaline cartilage (factor 5.3) and in the medial than the lateral compartment (factor 1.2). HCC/MC were already detectable with only mild cartilage lesions and the amount correlated with histological cartilage degeneration, but not with age.

CONCLUSIONS

The present study provides evidence that meniscal and hyaline CC occurs in a pattern that is compatible with CC being a systemically driven process and that meniscal fibrocartilage is more prone to calcification than hyaline cartilage. Furthermore, the age-independent association between the amount of CC and the grade of degeneration in both hyaline and meniscal cartilage, suggests that CC is an obligatory early event in initiating cartilage degeneration.

Low-dose computed tomography as diagnostic tool in calcium pyrophosphate deposition disease arthropathy: focus on ligamentous calcifications of the wrist

OBJECTIVES

To identify specific morphologic features of calcium pyrophosphate deposition disease (pseudogout, CPPD) manifestations of the wrist as detected using low-dose CT-scans.

METHODS

In this retrospective study 46 patients with arthritis of the wrist were included. All patients underwent a low dose CT scan of both wrists on a 320-row detector in volume scan mode. Individual radiation exposure was recorded for all patients. Two blinded raters independently evaluated osteoarthritis, cysts, erosions, calcifications (cartilage and ligaments separately) and carpal misalignment in 33 specified locations. An expert rheumatologist classified the patients as CPPD positive or negative. Fisher's exact test was applied to identify differences between both groups. Receiver operating characteristics (ROC) analyses with calculations of area under the curve (AUC) were carried out for both in the literature established and newly identified imaging findings for each rater individually.

RESULTS

Twenty-seven patients were classified as CPPD, 19 patients as other diagnoses. Ligamentous calcifications were significantly more prevalent in the CPPD group (p<0.05). All non-ligamentous findings revealed no difference in frequency. AUC analysis for established findings (0.675; 0.619 - rater 1; 2) vs. ligamentous calcifications (0.786 both raters) showed a markedly higher diagnostic accuracy for the latter. Effective radiation exposure was determined to be 0.019-0.095 mSv per patient.

CONCLUSIONS

Calcifications of carpal ligaments are highly specific morphologic features of CPPD arthropathy. Low-dose CT is a useful tool to detect these calcifications at a radiation exposure similar to a standard radiograph.

Issues in CPPD Nomenclature and Classification

PURPOSE OF REVIEW

This paper covers confusion and challenges in the nomenclature of calcium pyrophosphate deposition disease. Clinicians, investigators, and patients are faced with a variety of terms that are used to describe CPPD and its phenotypes, and clarity is greatly needed to help advance research and patient care. Motivation for the upcoming development of CPPD classification criteria is reviewed.

RECENT FINDINGS

EULAR proposed recommended terminology for CPPD in 2011. International Classification of Diseases (ICD-9 and ICD-10) billing codes identify definite or probable CPPD with variable accuracy depending on the clinical setting and comparator group. READ diagnostic codes have been employed to identify pseudogout in UK datasets but their accuracy has not been evaluated. CPPD classification criteria will provide a system for identifying a relatively homogenous group of patients to be included in clinical studies, enabling comparison of outcomes across studies. CPPD nomenclature remains challenging for clinicians, investigators, and patients. A lay-friendly definition of CPPD, using easily accessible terminology, would be welcome. CPPD classification criteria are a necessary step in moving forward CPPD clinical research and may involve a range of clinical, laboratory, and imaging modalities.

[A muscular calcium pyrophosphate deposition pseudo-abscess: An atypical localization of chondrocalcinosis]

INTRODUCTION

Chondrocalcinosis results from calcium pyrophosphate crystals deposition in the joints. We report an exceptional case of aseptic psoas abscess with a deposition of calcium pyrophosphate crystals.

CASE REPORT

A 92-year-old man presented to our department for an acute onset of inflammatory pain in the left hip. Computed tomography detected a coxofemoral arthritis and multiple intramuscular collections located in the iliopsoas muscle and the gluteus minimus. A sample of the fluid was obtained with a guided aspiration, and its analysis revealed an inflammatory liquid with no bacteria but numerous calcium pyrophosphate crystals. The final diagnosis was thus a muscular calcium pyrophosphate deposition pseudo-abscess, associated with a hip arthritis.

CONCLUSION

Hip chondrocalcinosis is unusual, and the association with intramuscular deposition of calcium pyrophosphate crystals seems extremely rare as we found only four other published cases. A microcrystalline arthritis could have spread from the coxofemoral joint through the iliopsoas bursa and into the muscle. However, the imaging aspect with an abscess and a predominant muscular injury might suggest a mechanism of crystal formation originating directly within the muscle. The outcome was always favourable even if some patients required surgery.

Clinical and ultrasound findings in patients with calcium pyrophosphate dihydrate deposition disease

AIM

To evaluate the presence and distribution of calcium pyrophosphate (CPP) deposits in joints commonly affected by CPP deposition (CPPD) disease (acromio-clavicular, gleno-humeral, wrists, hips, knees, ankles, and symphysis pubis joints) using ultrasound (US).

MATERIAL AND METHODS

Thirty consecutive patients fulfilling McCarty diagnostic criteria for CPPD were consecutively enrolled in the study. The data registered using the US included the affected joints, the calcification site, and the pattern of calcification (thin hyperechoic bands, parallel to the surface of the hyaline cartilage, hyperechoic spots, and hyperechoic nodular or oval deposits). The presence of CPP crystals in knees was confirmed by polarized light microscopy examination of the synovial fluid and radiographs of the knees were performed in all patients.

RESULTS

In 30 patients, 390 joints were scanned, (13 joints in every patient). The mean±standard deviation number of joints with US CPPD evidence per patient was 2.93±1.8 (range 1-9). The knee was the most common joint involved both clinically and using US examination. The second US pattern (with hyperechoic spots) was the most frequent. Fibrocartilage calcifications were more common than hyaline calcification. Using radiography as reference method, the sensitivity and specificity of US for diagnosis CPPD in knees was 79.31%, 95CI(66.65%-88.83%), and 14.29%, 95CI(1.78%-42.81%), respectively.

CONCLUSIONS

The knee is the most frequent joint affected by CPPD. The second ultrasound pattern is the most common. CPPD affects the fibrocartilage to a greater extent than the hyaline cartilage.

Pseudogout of the Transverse Atlantal Ligament: An Unusual Cause of Cervical Myelopathy

Background:

Calcium pyrophosphate dihydrate deposition in the cervical spine is infrequently symptomatic. This is especially true at the craniocervical junction and upper cervical spine.

Case Report:

A 70-year-old previously healthy woman presented with a progressive cervical myelopathy of four months duration.

Results:

Examination revealed sensorimotor findings consistent with an upper cervical myelopathy. Radiological studies (plain radiographs, computed tomography, and magnetic resonance imaging) revealed C1-2 instability, and a well-defined extradural 3cm x 1cm retro-odontoid mass causing spinal cord compression. Transoral resection of the mass was performed followed by posterior C1-2 stabilization. Histological examination of the mass confirmed calcium pyrophosphate dihydrate deposition. Follow-up examination showed marked clinical and radiological improvement.

Conclusion:

Although uncommon, calcium pyrophosphate dihydrate deposition disease should be considered in the differential diagnosis of extradural mass lesions in the region of the odontoid.

Calcium pyrophosphate dihydrate crystal deposition disease (pseudogout) of lumbar spine mimicking osteomyelitis-discitis with epidural phlegmon

Calcium pyrophosphate dihydrate crystal deposition disease (pseudogout) of the axial spine is rare. To our knowledge, there are few reports of the disease presenting with a presumed diagnosis of infection in the lumbar spine. As reported here, the diagnosis of osteomyelitis-discitis with epidural phlegmon was presumed before intervention. We present the case of a 60-year-old man with radiographic imaging and worsening clinical presentation at 2 consecutive hospitalizations. Axial magnetic resonance imaging originally showed increased signal intensity at the L5-S1 disk, which suggested an infectious rather than inflammatory process. Aspiration and biopsy at the time were nondiagnostic and showed no evidence of organisms. Two months after conservative treatment, the patient was readmitted with intractable low back pain and radiating bilateral leg pain. Repeat imaging showed increased interval signal in the L5-S1 disk, as well as enhancing soft-tissues that now extended to adjacent levels with extensive erosive changes. After surgical intervention for suspected infection, all cultures and stains for organisms were negative. Final pathology showed granulation tissue with focal inflammatory changes and calcium pyrophosphate crystal deposition. Although pseudogout is rare, physicians should add the disorder to the differential diagnosis for low back pain with radiculopathy and presumed infection.

[Chondrocalcinosis of the temporomandibular joint revealed by a hearing loss: a case report]

INTRODUCTION

Chondrocalcinosis is a microcrystalline arthropathy that principally affects the knee. It is a rare disorder, usually asymptomatic, that occurs mainly in the elderly people.

PURPOSE

To report a case of a temporomandibular joint chondrocalcinosis with ossicular contact revealed by a conductive hearing loss.

CASE REPORT

We describe the case of a 57-year-old man with a right conductive sudden hearing loss of 15 dB. The CT scan revealed a lytic lesion in the right attic extended to the middle cerebral fossa in contact with the ossicles with a suspicion of lysis of the head of the malleus. MRI showed a lesion enhancing after gadolinium injection on T1 weighted images. A biopsy revealed a chondrocalcinosis of the temporomandibular joint. Due to the complexity of surgical excision and the benin character of the lesion, a medical treatment and a radiologic follow-up every six months were proposed.

CONCLUSION

Chondrocalcinosis of the temporo-mandibular joint is rare especially when it is revealed by a hearing loss. We present here a review of the literature.

Pseudogout of the temporomandibular joint: an uncommon cause of temporomandibular joint pain and swelling

BACKGROUND

Pseudogout, or calcium pyrophosphate deposition, is a rare cause of pain, swelling, and trismus of the temporomandibular joint (TMJ). Diagnosis and management of the lesion are discussed.

CASE DESCRIPTION

A 58-year-old female had a 2-month history of progressive swelling of right TMJ associated with trismus and facial pain. Imaging of the TMJ revealed a mixed radiolucent and radiopaque lesion associated with the right TMJ joint space. Surgical excision was performed successfully via preauricular approach. Pathology was consistent with calcium pyrophosphate deposition of the TMJ, also known as pseudogout. Surgical excision successfully treated her symptoms as expected. She is now disease free without recurrence.

CLINICAL IMPLICATIONS

Pseudogout is a rare cause of TMJ pain, swelling, and trismus that should be included in the differential of joint pain and dysfunction. It can be treated successfully with surgery.

[Chondrocalcinosis and calcium pyrophosphate (CPP) crystal deposition disease in 2010]

Chondrocalcinosis may be asymptomatic or take three classical forms (acute recurrent inflammatory, chronic inflammatory, with osteoarthritis). Apart form that, CPP crystal arthropathies can mimic several rheumatic diseases, including polymyalgia, septic arthritis and spondylodiscitis. Several conditions can predispose to chondrocalcinosis, including hemochromatosis, hyperparathyroidism, familial hypocalciuric hypercalcemia, hypomagnesemia and treatment with tacrolimus or diuretics. The diagnostic sensitivity of ultrasound seems better than radiography and CT is useful in spinal forms but whenever possible, the identification of crystals in synovial fluid remains essential. NSAIDs and/or glucocorticoids are frequently sufficient to control symptoms but methotrexate, at anti-inflammatory doses (10-20 mg/wk) appears useful in refractory forms.

Chondrocalcinosis of the temporomandibular joint: a rare but important diagnosis

Patients with preauricular masses present with a wide range of pathologies, the most common of which are neoplasms of the parotid gland, metastatic or inflammatory disease, and enlarged periparotid lymph nodes. Other possibilities include lesions that arise from the skull base or the temporomandibular joint (TMJ). Chondrocalcinosis is a common age-related phenomenon that has a predilection for fibrocartilage. Although it can involve any joint, the knee is by far the most common site; involvement of the TMJ is very rare. We describe a case of chondrocalcinosis of the TMJ that manifested as a preauricular swelling and mimicked a parotid tumor, and we discuss the pathophysiology and radiographic characteristics of this disease.

[Tophaceous calcium pyrophosphate dihydrate deposits in a finger]

Calcium pyrophosphate dihydrate (CPPD) deposits are frequently observed in joint tissues. They can also occur in other tissues and present as a tophus. Contrarily to gout, a CPPD tophus is exceptionally localized in a finger. This presentation concerns a 81-year-old man who developed a huge tumor-like tophus of CPPD crystals on the antero-lateral side of his 3rd right finger, reducing superficial sensibility and eroding the proximal phalanx. Similarly to the majority of the rare previous reported cases, there was no associated chondrocalcinosis and the diagnosis was only made by the histological examination of the resected tissues. Better knowledge of this entity could avoid enlarged surgery as it has been done on some occasion.

Association between crystals and cartilage degeneration in the ankle

OBJECTIVE

Monosodium urate (MSU) and calcium pyrophosphate dihydrate (CPPD) crystals have been observed in synovial joints both before and after the onset of osteoarthritis (OA). The relationship between crystals and OA, however, remains controversial. We compared histologic and immunohistochemical patterns in articular cartilage of ankle joints with and without crystals.

METHODS

A sample of 7,855 human cadaveric tali was examined for the presence of surface and beneath-the-surface crystals. A random subsample of tali with and without crystals underwent crystal analysis by Fourier transform infrared spectroscopy (FTIR), histologic examination, and immunohistochemistry for S100 protein, superficial zone protein, collagen X, cSRC.

RESULTS

The prevalence of grossly visible crystals in the pool of donors over 18 years of age was 4.7% and correlated with advanced age, male sex, and obesity. Crystals were strongly associated with cartilage lesions and these lesions appeared to be biomechanically induced, being located where opposing articular surfaces might not be in congruence with each other. Thirty-four percent of the random subsamples of crystals upon which FTIR was performed contained CPPD, and the remainder were MSU crystals. Both crystal types were associated with higher levels of superficial zone protein and collagen X.

CONCLUSION

We show that the presence of surface crystals of either MSU or CPPD is strongly correlated with cartilage lesions in the talus. The histologic similarities in cartilage from joints with CPPD crystals compared to those with MSU crystals, together with what is known about the dramatically different etiologic factors producing these crystals, strongly suggest that these lesions are biomechanically induced.

Tophaceous calcium pyrophosphate dihydrate deposition disease of the temporomandibular joint

Tophaceous pseudogout is a rare manifestation of calcium pyrophosphate dihydrate (CPPD) deposition disease that particularly affects the temporomandibular joint (TMJ). We describe a case of tophaceous pseudogout and review the literature. Thirty-four cases of chronic CPPD deposition disease affecting the TMJ are described. Symptoms usually included pain and swelling. Most patients required surgery because of extensive crystal deposits, usually localized to the joint and adjacent structures but occasionally invasive. For many patients, malignancy was the preoperative diagnosis. Although patients with acute pseudogout of the TMJ may have involvement of other joints, tophaceous pseudogout was predominantly isolated to the TMJ.

Efficacy of tidal irrigation in Milwaukee shoulder syndrome

OBJECTIVE

To assess the efficacy of tidal irrigation in patients with Milwaukee shoulder syndrome (MSS).

METHODS

Ten patients with clinical diagnosis of MSS underwent ultrasound examination and tidal irrigation followed by instillation of methylprednisolone and tranexamic acid. A single shoulder was treated in 9 cases; in one patient with bilateral shoulder involvement, both shoulders were treated at different times. Six patients had longlasting disease (Group A) unsuccessfully treated with repeated joint fluid aspirations and intraarticular corticosteroid injections. Four patients had recent-onset illness without radiologic damage but with clinical findings similar to classic MSS (Group B), not previously treated with corticosteroid injections with symptoms dating from 3 months or less. Clinical examination including evaluation of adverse events, range of motion, and pain score by a 100 mm horizontal visual analog scale was scheduled just before tidal irrigation and after 2 and 6 months following the procedure in all cases.

RESULTS

Short- and longterm safety was excellent in all patients. Group A patients experienced short-lived improvement so that tidal irrigation had to be repeated within 6 to 10 months. No further therapy was necessary in any of the Group B patients during a mean followup of 16.5 months (range 12-24) due to a persistent clinical improvement without clinically detectable joint effusion.

CONCLUSION

Closed-needle joint irrigation is a minimally invasive procedure, which led to a significant improvement in both pain and active motion in patients with longstanding symptoms. Patients with recent-onset disease recovered completely.

Angiogenesis in the synovium and at the osteochondral junction in osteoarthritis

OBJECTIVES

We hypothesised that osteochondral and synovial angiogenesis in osteoarthritis (OA) are independent processes. We investigated whether indices of osteochondral and synovial angiogenesis display different relationships with synovitis, disease severity and chondrocalcinosis in patients with OA.

DESIGN

Synovium and medial tibial plateaux were obtained from 62 patients undergoing total knee joint replacement for OA (18 [29%] had chondrocalcinosis) and from 31 recently deceased people with no evidence of joint pathology post-mortem (PM). Vascular endothelium, proliferating endothelial cells (ECs) and macrophages were quantified by immunohistochemistry for CD34, CD31/Ki67 and CD14, respectively. Grades were assigned for radiographic and histological OA disease severity, clinical disease activity and histological synovitis (based on cellular content of the synovium).

RESULTS

Blood vessels breached the tidemark in 60% of patients with OA and 20% of PM controls. Osteochondral vascular density increased with increasing cartilage severity and clinical disease activity scores, but not with synovitis. Synovial EC proliferation, inflammation and macrophage infiltration were higher in OA than in PM controls. Synovial angiogenesis indices increased with increasing histological synovitis, but were not related to osteochondral vascular density or other indices of OA disease severity. OA changes were more severe in patients with concurrent chondrocalcinosis. Chondrocalcinosis was not associated with increased angiogenesis or histological synovitis beyond that seen in OA alone.

CONCLUSION

Osteochondral and synovial angiogenesis appear to be independent processes. Osteochondral vascularity is associated with the severity of OA cartilage changes and clinical disease activity, whereas synovial angiogenesis is associated with histological synovitis. Modulation of osteochondral and synovial angiogenesis may differentially affect OA disease.

Cervicomedullary compression secondary to massive calcium pyrophosphate crystal deposition in the atlantoaxial joint with intradural extension and vertebral artery encasement

BACKGROUND

Deposition of CPPD crystals occurs in the fibrous and hyaline cartilage of the joints and intervertebral disks of the spine. Half of patients known to have chondrocalcinosis had asymptomatic calcification in the odontoid region. The cases of 12 patients with a spinal cord syndrome secondary to CPPD deposition in the odontoid region were published in the literature. In all those cases, the mass lesion was extradural in location with good outcome after surgical decompression via the transoral route.

CASE DESCRIPTION

We report on a rare case of large periodontoid CPPD deposition causing cervicomedullary compression, erosion of the overlying bone, and underlying dura with intradural extension and vertebral artery encasement.

CONCLUSIONS

Calcium pyrophosphate dihydrate is a rare cause of cervicomedullary compression. Intradural extension of periodontoid CPPD has not been reported on.

Evaluation of human knee meniscus biopsies with near-infrared, reflectance confocal microscopy. A pilot study

Knee cartilage biopsy is used to confirm the pathology in both clinical and experimental conditions and often guides diagnosis and therapeutic strategies. Current histopathological techniques are time consuming, induce tissue artefacts and often prevent further evaluation, once the tissue has been fixed. Hence, there is a potential need for a fast and nondestructive imaging technique for unfixed tissue. Near-infrared, reflectance confocal microscopy (CM) allows real-time, virtual sectioning of unstained, bulk tissue samples. This pilot study evaluates the use of CM in the assessment of meniscus histopathology in a series of 26 freshly-excised human meniscus samples compared to standard light microscopy of stained sections. CM images of the meniscus show cell and matrix detail, depicting morphologic features of collagen and elastic fibres, vessels and nerve endings. In addition, crystal deposits of gout and pseudogout are also demonstrable. Thus, CM is a novel imaging technique that could enable the pathologist to make a rapid microscopic evaluation of cartilage in a fresh and unfixed fashion.

Chondrocalcinosis

In this paper introduces a rare case of chondrocalcinosis of the temporomandibular joint secondary to hyperparathyroidism, diagnosed in a 64-year-old man. The patient complained of symptoms characterized by the presence of a swelling in the left pretragic preauricular region, accompanied by a limitation of the mandibular movements. Radiographic examinations suggested a diagnosis of synovial chondromatosis. Subsequently definitive histological analysis removed mass stated for a chondrocalcinosis of the left temporomandibular joint. The differential diagnosis is very hard, in this case it has been difficult for the rarity of the pathology described in literature; the exact diagnosis can be only formulated on histologic and citologic examination of the mass excised.

Open-Label Study of Clarithromycin in Patients with Undifferentiated Connective Tissue Disease

OBJECTIVE

The macrolide family of antibiotics (erythromycin, clarithromycin, and others), have both antimicrobial and immunomodulatory effects. This study explored the effect of clarithromycin on the clinical course of patients with undifferentiated connective tissue disease (UCTD) in a 12-week open-label study.

METHODS

The diagnosis of UCTD was based on symptoms/signs of connective tissue disease, and the presence of 1 or more positive autoimmune disease tests, but with insufficient criteria to make a definitive diagnosis. Screening and monthly follow-up visits over 12 weeks included the following: history and physical examination; concurrent medications; the 68/66 tender/swollen joint count; visual analog scores 0 to 100 mm for patient and physician global assessment of disease activity, and patient pain; antinuclear antibody panel, rheumatoid factor, erythrocyte sedimentation rate, C-reactive protein, and blood chemistry.

RESULTS

Seven patients with rheumatic disease were treated with clarithromycin; 6 of 7 had symptomatic relief. Two subjects treated empirically before the decision to perform an open-label study responded favorably. Four of 5 patients who completed the prospective open-label study had mean maximal improvements from baseline of 78, 75, and 79% in patient pain, patient global, and investigator global assessments, respectively. Pain relief occurred as early as 1 week. Drug withdrawal with rechallenge in 2 patients resulted in flare followed by recapture of symptomatic relief.

CONCLUSIONS

Clarithromycin, a macrolide antibiotic, led to clinical improvement in patients with UCTD. Efficacy and safety data support further investigation of macrolide antibiotic use as a primary or adjunctive treatment in various connective tissue diseases.

CPPD complicating other forms of inflammatory arthritis

Calcium pyrophosphate deposition (CPPD) disease is confirmed as equally common in rheumatoid arthritis by synovial fluid and macroscopic skeletal examination. Furthermore, differential frequencies in rheumatoid arthritis and spondyloarthropathy provide additional insights to the "lumper-splitter" question.

Calcium Deposition and Associated Chronic Diseases (Atherosclerosis, Diffuse Idiopathic Skeletal Hyperostosis, and Others)

Extracellular matrix mineralization or calcification occurs in many pathologic conditions, including atherosclerosis, medial wall calcification, diffuse idiopathic skeletal hyperostosis, and chondrocalcinosis. Vascular wall calcification is the most common and involves two mechanisms: passive calcification resulting from breakdown of the protection system and active calcification resulting from transdifferentiation of mesenchymal cells in the vascular wall to bone. Although reports are conflicting, several matrix proteins are identified as protective factors against dystrophic calcification in nonosseous tissues. Serum matrix Gla protein may be a marker of osteometabolic syndromes that cause hyperostosis and plays a role in Milwaukee shoulder syndrome.

Pseudogout attack induced during etidronate disodium therapy

We report the first case of pseudogout attack in the distal interphalangeal (DIP) joints during etidronate disodium therapy. A 64-year-old woman had intermittent administration of etidronate disodium (Didronel; Sumitomo, Osaka, Japan) alone because of osteoporosis. Each cycle consisted of a daily dose of 200 mg for 2 weeks, repeating every 12 weeks. Two weeks after completing the third cycle, severe pain and swelling occurred in the DIP joints of the right middle, ring, and left ring finger; and skin ulcer formation was observed on the dorsal side of the DIP joints of the right middle and ring fingers as well as the left ring finger. Because monoclinic calcium pyrophosphate crystals were detected in the synovial fluid from the DIP joints of the right middle finger, we diagnosed these symptoms as induced by pseudogout attack. Oral loxoprofen sodium at a daily dose of 180 mg resulted in rapid symptom resolution. A decrease in function of calcium metabolism in elderly persons has been reported to be a cause of pseudogout attack. On the other hand, distal interphalangeal joint arthritis presenting as Heberden's nodes is a common condition in elderly patients. Therefore, pseudogout attack should be considered as an adverse drug reaction when administering bisphosphonate in elderly patients with Heberden's nodes.

Degenerative spine disease : pathologic findings in 985 surgical specimens

A number of pathologic changes have been reported in spinal surgery specimens. The frequency of many of these is not well defined. We retrospectively reviewed the histologic features of 985 extradural spinal surgery specimens. Of the cases, 1.6% were identified clinically as synovial cysts. In addition, synovial tissue was seen in another 5.3% of cases, often embedded within disk material. Neovascularization of disk tissue was present in 8.1% of cases, chondrocyte clusters in 18.3%, and calcium pyrophosphate crystals in 2.8%, predominantly within disk material. With the exception of crystal deposits, all of these changes were significantly more common in the lumbar spine. A better understanding of cell-based degenerative changes will become essential with increasing research into cell-based therapies for spinal disk disease. We report data on the frequency of different pathologic changes and describe synovial metaplasia as a reactive change not previously reported.

Gout-associated uric acid crystals activate the NALP3 inflammasome

Development of the acute and chronic inflammatory responses known as gout and pseudogout are associated with the deposition of monosodium urate (MSU) or calcium pyrophosphate dihydrate (CPPD) crystals, respectively, in joints and periarticular tissues. Although MSU crystals were first identified as the aetiological agent of gout in the eighteenth century and more recently as a 'danger signal' released from dying cells, little is known about the molecular mechanisms underlying MSU- or CPPD-induced inflammation. Here we show that MSU and CPPD engage the caspase-1-activating NALP3 (also called cryopyrin) inflammasome, resulting in the production of active interleukin (IL)-1beta and IL-18. Macrophages from mice deficient in various components of the inflammasome such as caspase-1, ASC and NALP3 are defective in crystal-induced IL-1beta activation. Moreover, an impaired neutrophil influx is found in an in vivo model of crystal-induced peritonitis in inflammasome-deficient mice or mice deficient in the IL-1beta receptor (IL-1R). These findings provide insight into the molecular processes underlying the inflammatory conditions of gout and pseudogout, and further support a pivotal role of the inflammasome in several autoinflammatory diseases.

Hypomagnesemia and chondrocalcinosis in short bowel syndrome

Chondrocalcinosis is a result of deposition of calcium pyrophosphate dihydrate (CPPD) crystals in cartilage and fibrocartilage. Chondrocalcinosis is usually sporadic but has also been associated with a variety of metabolic diseases including hypomagnesemia. Reported cases of hypomagnesemia associated chondrocalcinosis were mostly due to renal genetic disorders such as Bartter's or Gitelman's syndrome. We describe 3 patients with chronic hypomagnesemia induced by short bowel syndrome who developed symptomatic chondrocalcinosis. CPPD crystals were identified by polarizing light microscopy in one patient. The underlying intestinal pathology was radiation enteritis in 2 patients and mesenteric arterial thrombosis in the third. Our observations strengthen the hypothesis of a role for magnesium in CPPD crystal deposition disease.

An update on the treatment options for gout and calcium pyrophosphate deposition

Gout and calcium pyrophosphate deposition disease are two common causes of inflammatory joint disease. Despite differences underlying their pathogenesis, their clinical presentation and treatment share some common features. Optimal treatment for both requires prompt resolution of acute synovitis, reduction of chronic joint damage and management of associated conditions. Available therapeutic interventions and future strategies are reviewed in this article.

Pathogenesis of calcium crystal deposition in the ligamentum flavum correlates with lumbar spinal canal stenosis

OBJECTIVE

To investigate the histological and immunohistochemical properties of degenerative changes and calcium crystal deposition in the lumbar ligamentum favum.

METHODS

We examined the ligamentum flavum harvested from 119 surgical cases with symptomatic lumbar spinal stenosis. Sections of the ligament were examined by scanning electron microscopy (SEM), energy dispersive X-ray micro-analysis, and were immunostained for S-100 protein, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and CD34. The results were compared with those of ligament tissue harvested from 10 cases of lumbar disc herniation.

RESULT

The elastic fibres of the ligamentum favum showed regular, or sometimes irregular, and fragmented fibre bundles. Large areas of fibrosis with reduced elastic component and increased collagenous tissue were frequently seen in the degenerated ligaments. Calcium crystal deposits were observed in these fibrous ligaments, associated with many hypertrophic chondrocytes, and with small blood vessel formation. These chondrocytes stained positively for S-100 protein, VEGF and bFGF Calcium pyrophosphate dihydrate crystals were identified in the calcium deposit area.

CONCLUSION

We believe that rupture of elastic fibre bundles is the first change to occur in degeneration of the ligamentum favum. Calcium crystal deposition was seen within these fibrous and chondrometaplastic areas. Hypertrophic chondrocytes regulate crystal formation and tissue reconstruction by secreting cytokines.

Genetics of chondrocalcinosis

Rapid developments in genetic analysis have enabled the dissection of a variety of arthropathies that are inherited in a Mendelian manner. These disorders include calcium crystal arthropathies such as calcium pyrophosphate dihydrate deposition (CPPD) disease and hydroxyapatite deposition disease. In CPPD disease, mutations in a recently discovered gene, ANKH, have been demonstrated in five affected families and may also be associated with the idiopathic deposition of calcium pyrophosphate dihydrate crystals. The product of ANKH appears to be involved in cellular transport of inorganic pyrophosphate (PPi) and mutations in ANKH have been shown to have a significant impact on the regulation of intra- and extracellular levels of PPi. In families with hydroxyapatite deposition disease, no gene locus has yet been linked to the disorder.

Intracellular and extracellular CPPD crystals are a regular feature in synovial fluid from uninflamed joints of patients with CPPD related arthropathy

OBJECTIVES

To determine whether calcium pyrophosphate dihydrate (CPPD) crystals can be found in the synovial fluid of non-inflamed joints in patients with CPPD related arthropathy; if so, to determine whether they interact with cells and produce subclinical inflammation in this setting.

METHODS

74 synovial fluid samples were obtained from non-inflamed knees of 74 patients with CPPD related arthropathy. Identification of CPPD crystals and synovial fluid cell counts were done manually in undiluted samples using a haematocytometric chamber. A supravital stain (Testsimplets, Boehringer Mannheim) was used to carry out differential counts and to assess the presence of intracellular crystals.

RESULTS

All 74 samples contained CPPD crystals. The mean cell count was 301.4 cells/microl (95% confidence interval (CI), 216.6 to 386.4; range 22 to 2302.5). Mononuclear cells accounted for 83.2% (95% CI, 80.4% to 86.1%; range 43% to 99%), the rest being polymorphonuclear (PMN) cells (16.8% (95% CI, 13.9% to 19.6%; range 1% to 57%)). All the samples contained intracellular CPPD crystals, which were found in 24.0% of all the cells (95% CI, 20.1% to 27.9%; range 1% to 78%). Most of the intracellular crystals were inside mononuclear cells (22.2% of all the cells (95% CI, CI 18.5% to 25.9%)), although some PMN also contained them (1.8% of all the cells (95% CI, 1.1% to 2.4%)).

CONCLUSIONS

CPPD crystals are normally found in synovial fluid of non-inflamed joints of patients with CPPD related arthropathy, and they interact with cells. The raised cell counts and percentage of PMN suggest mild subclinical inflammation in these joints.

Inflammation and tissue damage in crystal deposition diseases

PURPOSE OF REVIEW

The crystal-induced arthropathies are characterized by self-limiting episodes of acute inflammation and chronic tissue damage. This review summarizes recent advances in the understanding of the cellular responses to monosodium urate, calcium pyrophosphate dihydrate and basic calcium phosphate crystals.

RECENT FINDINGS

Factors such as the myeloid related proteins, endothelin-1 and the complement membrane attack complex have been recently identified as mediators of acute crystal-induced inflammation. In addition, signalling pathways involved in both acute inflammation and tissue damage in crystal arthropathies have been further clarified. The potential of macrophage-derived transforming growth factor beta1 to play a key role in the resolution phase of acute gout has also been demonstrated.

SUMMARY

Recent work has provided new insights into the regulation of both acute and chronic articular responses to inflammatory microcrystals. Further analysis of these responses may identify potential therapeutic targets for management of the crystal-induced arthropathies.

Diagnosis of calcium pyrophosphate dihydrate crystal deposition disease: ultrasonographic criteria proposed

OBJECTIVE

To investigate by high frequency ultrasonography the appearance of calcium pyrophosphate dihydrate (CPPD) calcifications, in the most commonly affected sites in CPPD disease, and the relationship between ultrasonographic CPPD deposits and the presence of CPPD crystals in synovial fluid.

METHODS

Three ultrasonographic patterns of CPPD calcification were identified and 11 patients enrolled. A control group comprised 13 patients with no evidence of CPPD deposits. Synovial fluid was aspirated from all patients and controls and examined for identification of crystals. All patients underwent a standard radiography examination at the same sites investigated by ultrasound.

RESULTS

In all patients with ultrasonographically defined CPPD deposits, CPPD crystals were found in the synovial fluid. In two cases, standard radiographic examination did not show evidence of the calcific deposits that were identified by ultrasonography. CPPD crystals were not found in the synovial fluid of controls. In four control group patients, ultrasonography identified calcifications defined as deposits of another nature.

CONCLUSIONS

The ultrasonographic pattern used in this study for the diagnosis of CPPD disease demonstrated a very high correlation with the presence of CPPD crystals in synovial fluid. Ultrasonography demonstrated a sensitivity and specificity at least equal to that of radiography in identifying CPPD crystal calcifications.

Calcium pyrophosphate dihydrate crystal deposition disease of the temporomandibular joint

A case of a 74-year-old woman with calcium pyrophosphate dihydrate crystal deposition disease of the temporomandibular joint (TMJ) is presented. This disease rarely involves the TMJ and is not usually considered in the differential diagnosis of TMJ disorders. To our knowledge, only 23 cases have been reported in the literature and only four without any destructive changes of the condyle as in the present case.

Cervical spine and crystal-associated diseases: imaging findings

The cervical spine may be specifically involved in crystal-associated arthropathies. In this article, we focus on the three common crystals and diseases: hydroxyapatite crystal deposition disease, calcium pyrophosphate dihydrate (CPPD) deposition disease, and monosodium urate crystals (gout). The cervical involvement in crystal-associated diseases may provoke a misleading clinical presentation with acute neck pain, fever, or neurological symptoms. Imaging allows an accurate diagnosis in typical cases with calcific deposits and destructive lesions of the discs and joints. Most of the cases are related to CPPD or hydroxyapatite crystal deposition; gout is much less common.

Articular calcified cartilage canals in the third metacarpal bone of 2-year-old thoroughbred racehorses

We describe morphological aspects of the articular calcified cartilage mineralizing front 'tidemark' in the distal joint surface of the third metacarpal bone from 14 horses. Compositional backscattered electron scanning electron microscopy and confocal scanning light microscopy were conducted on polymethylmethacrylate (PMMA)-embedded medio-lateral slices. After maceration, scanning electron microscopy (SEM) was used to study the calcified cartilage surface in the 'wedges' intervening between the slices. An anatomically reproducible clustering of canals in the calcified cartilage was found at one site on the sagittal ridge in all the horses. The site is one that is relatively less loaded during joint function. These canals through calcified cartilage result from osteoclastic resorption (cutting cones) penetrating from bone through to the non-mineralized hyaline articular cartilage. Their presence may indicate a pathway for connection between bone and cartilage extracellular fluid. In one horse, repair of such canals by plugging with new calcified cartilage was demonstrated. Differences in the degree of mineralization of regions of cartilage were seen in the combined compositional-cum-topographical backscattered SEM images of the macerated 'tidemark' front. More-or-less circular patches of lower mineralization density were frequently centred on (and may possibly originate from) canals. These microanatomical features should be searched for in other joints, at other ages and in other species to discover their frequency and significance.

A case of chronic calcium pyrophosphate dihydrate crystal disease (tophaceous pseudogout) in the temporomandibular joint

Pseudogout is a rare joint disease which is characterized by the presence of calcium pyrophosphate dihydrate crystals in the intraarticular and periarticular tissue. The crystals tend to attach to fibrocartilage tissue. Pseudogout principally affects the knee and wrist joints. Involvement of the temporomandibular joint (TMJ) is very rare. There have been <20 cases reported world-wide. Both acute and chronic manifestations have been described. We present here an unusual case that necessitated a high condylectomy.

Fractal analysis of acceleration signals from patients with CPPD, rheumatoid arthritis, and spondyloarthroparthy of the finger joint

Arthritis is one of the leading causes of disability and affects a major segment of the population. Consequently, accurate diagnosis of arthritis is important. Arthritis due to calcium pyrophosphate deposition disease (CPPD), rheumatoid arthritis, and spondyloarthropathy, induce complex changes in the cartilage and the articular surface. The fractal dimension provides a measure of the complexity of a signal. Recently, we have developed non-invasive acceleration measurements to characterize the arthritic patients. The question remains if the fractal dimension of the acceleration signal is different for different arthritis conditions. The purpose of this study was to distinguish between different types of arthritis of the finger joint using the fractal dimension of the acceleration signal obtained from the finger joint of the arthritic patients. Acceleration signals were obtained from the finger joint of arthritis patients with rheumatoid arthritis, spondyloarthropathy, and calcium pyrophosphate deposition disease of the finger joint. ANOVA results showed that there were significant differences between the fractal dimension of acceleration signals from patients having calcium pyrophosphate deposition disease and rheumatoid arthritis and spondyloarthropathy. Fractal dimension of acceleration signals, in concert with other clinical symptoms, can be used to classify different types of arthritis.