Joint disorders in cystic fibrosis

Manifestation and staging of arthropathy in cystic fibrosis. Defining different stages of cystic fibrosis arthropathy using ultrasound imaging and clinical scoring

BACKGROUND

The true prevalence of cystic fibrosis arthropathy (CFA) remains unclear and may be significantly higher than previously reported. In recent studies, joint symptoms have been reported in up to 30% of adults with CF. This underlines the importance of CFA as a rising and clinically relevant co-morbidity. A clear definition of CFA is yet missing and its pathogenesis remains unclear. We investigated the clinical manifestation of CFA particularly via ultrasound (US) examination to define and implement a staging for clinical assessment.

METHODS

In a prospective cohort study between March 2018 and February 2020 a total of 98 consecutively recruited, adult cystic fibrosis (CF) patients underwent joint-US examination according to a newly developed ultrasound score (US-CFA). A clinical assessment including rheumatological scores (DAS28, HAQ) has been conducted as well as a specially designed questionnaire. Investigation on clinical and microbiological data, as well as a comprehensive laboratory analysis, were carried out. Cluster analysis has been performed to detect patterns defining different CFA stages based on disease activity.

RESULTS

US imaging has shown a considerable incidence of mild to moderate effusion as sign of joint inflammation/(teno-)synovitis. K-means clustering was used to distinguish 3 different stages of CFA based on the intensity of the detected effusion. These stages showed a significant association with disease activity (DAS28, p = 0.0004) as well as with patient-reported symptoms such as total weeks of CFA per year (p = 0.004), acute CFA (p = 0.015), chronic CFA (p = 0.016), disease burden (p = 0.04). Based on the US-CFA, 16% of patients suffered from severe CFA (II), 51% from intermediate CFA (I) and 33% did not present detectable arthritis. Positive serology for Chlamydophilia pneumoniae (IgA, IgG) and Chlamydia trachomatis (IgA, IgG) significantly correlated with the US-CFA.

CONCLUSIONS

The results of this study show that a definition and categorization for the clinical manifestation of CFA can be described through US examination, which is able to detect disease activity concordant with the DAS28 as a validated clinical score on arthritis. Defining these stages will lead to a better understanding of the clinical phenotype of the disease and will optimize diagnosis, therapy and research on CFA in the future.

Genome Editing for Cystic Fibrosis

Cystic fibrosis (CF) is a monogenic recessive genetic disorder caused by mutations in the CF Transmembrane-conductance Regulator gene (CFTR). Remarkable progress in basic research has led to the discovery of highly effective CFTR modulators. Now ~90% of CF patients are treatable. However, these modulator therapies are not curative and do not cover the full spectrum of CFTR mutations. Thus, there is a continued need to develop a complete and durable therapy that can treat all CF patients once and for all. As CF is a genetic disease, the ultimate therapy would be in-situ repair of the genetic lesions in the genome. Within the past few years, new technologies, such as CRISPR/Cas gene editing, have emerged as an appealing platform to revise the genome, ushering in a new era of genetic therapy. This review provided an update on this rapidly evolving field and the status of adapting the technology for CF therapy.

Prevalence and Impact of Rheumatologic Pain in Cystic Fibrosis Adult Patients

Background

With the improvement of cystic fibrosis (CF) patient survival, the prevalence of long-term complications increased, among them rheumatologic disorders.

Methods

The aim of this prospective study was to evaluate the prevalence of spinal and joint pain, and their impact on disability, anxiety, depression, and quality of life in CF adult patients.

Results

Forty-seven patients were analyzed, 72% of men, mean aged 28 years, with a mean body mass index of 22 kg/m² and a mean FEV₁% of 63%. Twenty-two patients (47%) described rheumatologic pain either spinal (n = 15, 32%) and/or joint pain (n = 14, 30%). Patients with spinal and/or joint pain were shorter (p = 0.023), more frequently colonized with Staphylococcus aureus (p < 0.008), had more frequent ΔF508 homozygous mutations (p = 0.014), and a trend for more impairment of the 6-min walking distance (p = 0.050). The presence of rheumatologic pain tended to be associated with disability according to the Health Assessment Questionnaire (HAQ) and anxiety. Compared with patients with no pain patients with both spinal and joint pain exhibited a more pronounced impact on the St George's Respiratory Questionnaire (SGRQ).

Conclusion

Rheumatologic pain is frequent in CF adult patients, and may affect daily living, anxiety and quality of life. Systematic assessment of rheumatologic pain should be included in the management of CF patients.

Risk factors for cystic fibrosis arthropathy: Data from the German cystic fibrosis registry

BACKGROUND

Epidemiology and potential risk factors for cystic fibrosis arthropathy (CFA) were studied in a relevant cystic fibrosis (CF) patient cohort.

METHODS

Cohort study of patients included in the German CF registry in 2016-2017. Descriptive analysis, exploratory tests and multivariable logistic regression were used to assess prevalence of CFA and associated potential risk factors for adult patients with/without chronic Pseudomonas aeruginosa infection.

RESULTS

6069 CF patients aged from 0 to 78 years were analysed. CFA was observed in 4.9% of the patients. Prevalence was significantly higher in adult patients (8.4%) compared to patients <18 years (0.7%; p<0.0001). Logistic regression analyses in adult patients (n=3319) showed that CFA was significantly associated with increasing age (OR=1.04; 95% CI: 1.02-1.05; p<0.0001), female gender (OR=2.10; 95%CI:1.52-2.90; p<0.0001), number of hospitalizations (OR=1.24; 95%CI:1.12-1.36; p<0.0001), chronic P. aeruginosa infection (OR=1.83; 95%CI:1.28-2.61; p=0.0009), CF-related diabetes (OR=1.69; 95%CI:1.23-2.33; p=0.0013), pancreatic insufficiency (OR=2.39; 95%CI:1.28-4.46; p=0.0060) and sinusitis/polyps (OR=1.91; 95%CI:1.39-2.62; p<0.0001). In a subgroup analysis of adults without chronic P. aeruginosa infection (n=1550) CFA was also significantly associated with increasing age, female gender, increasing number of hospitalizations, pancreatic insufficiency as well as sinusitis/polyps; antimycotic treatment associated only in this subgroup while association with CF-related diabetes was not significant.

CONCLUSION

CFA is a frequent and clinically relevant co-morbidity particularly in adult CF patients. CFA is significantly more common in patients with chronic P. aeruginosa colonization but associations with other indicators for a more severe disease course were identified regardless of P. aeruginosa colonization status.

CFTR regulates B cell activation and lymphoid follicle development

Background

Cystic fibrosis (CF) is an inherited disorder caused by mutations in the CF transmembrane conductance regulator (CFTR) gene that promotes persistent lung infection and inflammation and progressive loss of lung function. Patients with CF have increased lung lymphoid follicles (LFs) and B cell-activating factor of tumor necrosis factor family (BAFF) that regulates B cell survival and maturation. A direct role for CFTR in B cell activation and disease pathogenesis in CF remains unclear.

Methods

The number of LFs, BAFF⁺, TLR4⁺ and proliferation marker Ki67⁺ B cells in lung explants or resections from subjects with CF and normal controls was quantified by immunostaining. The role of CFTR in B cell activation and LF development was then examined in two independent cohorts of uninfected CFTR-deficient mice (Cftr^−/−) and wild type controls. The number of lung LFs, B cells and BAFF⁺, CXCR4⁺, immunoglobulin G⁺ B cells was examined by immunostaining. Lung and splenocyte B cell activation marker and major histocompatibility complex class II (MHC class II) expression was quantified by flow cytometry. Inflammatory cytokine levels were measured in supernatants from isolated B cells from Cftr^−/− and wild type mice stimulated in vitro with Pseudomonas aeruginosa lipopolysaccharide (LPS).

Results

There was a significant increase in well-formed LFs in subjects with CF compared to normal controls. Increased B cell activation and proliferation was observed in lung LFs from CF subjects as was quantified by a significant increase in B cell BAFF, TLR4 and Ki67 expression. Uninfected Cftr^−/− mice had increased lung LFs and BAFF⁺ and CXCR4⁺ B cells compared to wild type controls. Lung B cells isolated from uninfected Cftr^−/− mice demonstrated increased MHC class II expression. In vitro, isolated B cells from Cftr^−/− mice produced increased IL-6 when stimulated with LPS compared to wild type controls.

Conclusions

These data support a direct role for CFTR in B cell activation, proliferation and inflammatory cytokine production that promotes lung LF follicle development in cystic fibrosis.

Current and emerging comorbidities in cystic fibrosis

Cystic fibrosis transmembrane conductance regulator (CFTR) is expressed ubiquitously throughout the body. Thus, while respiratory manifestations dominate much of cystic fibrosis (CF) care, there are prominent multi-organ manifestations and comorbidities. In the general population, the number of comorbidities increases with aging. Few illnesses have experienced such a dramatic improvement in survival as CF, which has been transformed from an illness of childhood death to one of adult survival. Hence, as longevity increases in CF, it is paralleled by an increasing number of patients with multicomplex comorbidities availing of care from adult CF multi-disciplinary teams. This review gives an overview of the traditional CF associated comorbidities and those emerging in an aging adult cohort. While historically the treatment of CF focused on the consequences of CFTR dysfunction, the recent advent of CFTR modulators with the potential to enhance CFTR function represents an opportunity to potentially reverse or delay the development of some of the comorbidities associated with CF. Where evidence is available for the impact of CFTR modulatory therapy, namely ivacaftor on comorbidities in CF, this is highlighted.

Anti-inflammatory drugs and analgesics for managing symptoms in people with cystic fibrosis-related arthritis

BACKGROUND

Arthritis remains a relatively infrequent complication of cystic fibrosis, but is a cause of significant morbidity when it does occur. Two distinct types of arthritis are described in cystic fibrosis: cystic fibrosis-related arthropathy (CFA) and hypertrophic pulmonary osteoarthropathy (HPO). Management of arthritis in people with cystic fibrosis is uncertain and complex because of the underlying disease and its intense treatment. This is an update of a previously published review.

OBJECTIVES

To review the effectiveness and safety of pharmacological agents for the symptomatic management of cystic fibrosis-related arthritis in adults and children with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings.Date of most recent search: 19 January 2016.

SELECTION CRITERIA

Randomised controlled studies which compared the efficacy and safety of anti-inflammatory and analgesic agents (e.g. non-steroidal anti-inflammatory agents, systemic corticosteroids, intra-articular corticosteroids) with each other, with no treatment or with placebo for CFA and HPO.

DATA COLLECTION AND ANALYSIS

No relevant studies were identified.

MAIN RESULTS

No studies were included in this review.

AUTHORS' CONCLUSIONS

Although it is generally recognised that CFA may be episodic and resolve spontaneously, treatment with analgesics and anti-inflammatory agents may be needed. While this approach may be sufficient to manage symptoms, it is disappointing that no randomised controlled trials to rigorously evaluate these agents were found, nor could the authors identify any quasi-randomised. This systematic review has identified the need for a well-designed adequately-powered randomised controlled trial to assess the efficacy and safety of pharmacological agents for the symptomatic management of cystic fibrosis-related arthritis (CFA and HPO) in adults and children with cystic fibrosis. Studies should also better define the two conditions. A study has recently been conducted in CFA and may help fill this gap when analysed and published.There are no trials included in the review up to January 2016. We will continue to run searches to identify any potentially relevant studies; however, we do not plan to update other sections of the review until new studies are published.

Ultrasound and magnetic resonance imaging assessment of joint disease in symptomatic patients with cystic fibrosis arthropathy

OBJECTIVES

Cystic fibrosis arthropathy (CFA) is a term commonly used for joint pain with and without swelling seen in some patients with CF. Early studies into CFA focused on the presence of rheumatoid factor and immunological changes on synovial biopsy, with parallels drawn between respiratory and joint activity. Identification of anti-cyclic citrullinated peptide antibodies (anti-CCP) as a marker of rheumatoid arthritis (RA), along with increased access to sensitive imaging techniques including ultrasound (US) and magnetic resonance imaging (MRI), offer great potential to investigate and more accurately understand the type(s) of inflammatory arthritis that may underlie CFA. The aim of this study was to phenotype an active CFA cohort using serology and imaging, as a basis for further work in this understudied area.

METHODS

This was a prospective observational cohort study of symptomatic CFA patients presenting with joint pain. Participants underwent serological testing, clinical and US joint and entheseal assessment, as well as MRI of the most symptomatic joint/joint area.

RESULTS

Ten symptomatic patients were studied with 9/10 having positive clinical findings. Inflammatory changes on US were seen in 8/10 cases. Five patients had positive findings on MRI (3 of whom had received IV gadolinium contrast). This included patients with significant erosive changes. One patient was anti-CCP positive suggestive of RA, and two were anti-nuclear antibody positive.

CONCLUSION

Imaging, and to a lesser extent serology, identified inflammatory joint pathology in a proportion of cases, providing important data to explore in a large CFA cohort examining the clinical and imaging phenotype of this group.

Cystic fibrosis: what to expect now in the early adult years

As a testimony to advances in patient care, more individuals with cystic fibrosis are surviving into their adult years than ever before. The clinical epidemiology of this complex multi-organ disease is evolving and has changed dramatically over the past two to three decades. This article discusses the emergence of chronic disease-related co-morbidities such as CF-related diabetes, chronic kidney disease, bone disease, arthropathy, and depression. It also provides an overview of the many challenges confronted by adult CF care providers.

Disease modifying anti-rheumatic drugs in people with cystic fibrosis-related arthritis

BACKGROUND

Arthritis remains a relatively infrequent complication of cystic fibrosis, but is a cause of significant morbidity when it does occur. Two distinct types of arthritis are described in cystic fibrosis: cystic fibrosis-related arthropathy and hypertrophic osteoarthropathy. Management of arthritis in people with cystic fibrosis is uncertain and complex because of the underlying disease and its treatment.

OBJECTIVES

To review the effectiveness and safety of disease-modifying anti-rheumatic drugs for the management of arthritis related to cystic fibrosis in adults and children.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Cystic Fibrosis Trials Register which comprises references identified from comprehensive electronic database handsearches of relevant journal and abstract books of conference proceedings.Date of most recent search: 10 July 2012.

SELECTION CRITERIA

Randomised controlled trials which compared the efficacy and safety of disease-modifying anti-rheumatic drugs (e.g. methotrexate, gold, sulfasalazine, penicillamine, leflunomide, hydroxychloroquine and newer agents such as biologic disease modifying agents and monoclonal antibodies) with each other, with no treatment or with placebo for cystic fibrosis-related arthropathy or hypertrophic osteoarthropathy.

DATA COLLECTION AND ANALYSIS

No relevant studies were identified.

MAIN RESULTS

No studies were included in this review.

AUTHORS' CONCLUSIONS

Although it is generally recognised that cystic fibrosis-related arthritis can be episodic and resolve spontaneously, treatment with analgesics and anti-inflammatory agents may be needed. But when episodic symptoms progress to persistent disease, disease-modifying anti-rheumatic drugs may be needed to limit the course of the disease. It is disappointing that no randomised controlled trials to rigorously evaluate these drugs could be found. This systematic review has identified the need for a well-designed adequately powered randomised controlled trial to assess the efficacy and safety of disease-modifying anti-rheumatic drugs for the management of cystic fibrosis-related arthropathy and hypertrophic osteoarthropathy in adults and children with cystic fibrosis. However, given the infrequency of cystic fibrosis-related arthritis and the range of symptoms and severity, randomised controlled trials may not be feasible and well-designed non-randomised observational studies may be more appropriate. Studies should also better define the two conditions.

Anti-inflammatory drugs and analgesics for managing symptoms in people with cystic fibrosis-related arthritis

BACKGROUND

Arthritis remains a relatively infrequent complication of cystic fibrosis, but is a cause of significant morbidity when it does occur. Two distinct types of arthritis are described in cystic fibrosis: cystic fibrosis-related arthropathy (CFA) and hypertrophic pulmonary osteoarthropathy (HPO). Management of arthritis in people with cystic fibrosis is uncertain and complex because of the underlying disease and its intense treatment.

OBJECTIVES

To review the effectiveness and safety of pharmacological agents for the symptomatic management of cystic fibrosis-related arthritis in adults and children with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings.Date of most recent search: 16 December 2011.

SELECTION CRITERIA

Randomised controlled trials which compared the efficacy and safety of anti-inflammatory and analgesic agents (e.g. non-steroidal anti-inflammatory agents, systemic corticosteroids, intra-articular corticosteroids) with each other, with no treatment or with placebo for CFA and HPO.

DATA COLLECTION AND ANALYSIS

No relevant studies were identified.

MAIN RESULTS

No studies were included in this review.

AUTHORS' CONCLUSIONS

Although it is generally recognised that CFA may be episodic and resolve spontaneously, treatment with analgesics and anti-inflammatory agents may be needed. While this approach may be sufficient to manage symptoms, it is disappointing that no randomised controlled trials to rigorously evaluate these agents were found, nor could the authors identify any quasi-randomised. This systematic review has identified the need for a well-designed adequately-powered randomised controlled trial to assess the efficacy and safety of pharmacological agents for the symptomatic management of cystic fibrosis-related arthritis (CFA and HPO) in adults and children with cystic fibrosis. Studies should also better define the two conditions. A study has recently been conducted in CFA and may help fill this gap when analysed and published.There are no trials included in the review up to January 2012. We do not plan to update this review until new trials are published, although we will search the Group's Cystic Fibrosis Trials Register on a two-yearly cycle.

Treatment of cystic fibrosis associated cutaneous vasculitis with chloroquine

Vasculitis is a well recognised complication of Cystic Fibrosis. Corticosteroids are the mainstay of treatment but some cases can be resistant and may require additional disease modifying agents. We describe a case of steroid resistant cutaneous vasculitis which was successfully treated with chloroquine in addition to corticosteroids and a subsequent relapse with chloroquine alone.

Disease modifying anti-rheumatic drugs in people with cystic fibrosis-related arthritis

BACKGROUND

Arthritis remains a relatively infrequent complication of cystic fibrosis, but is a cause of significant morbidity when it does occur. Two distinct types of arthritis are described in cystic fibrosis: cystic fibrosis-related arthropathy and hypertrophic osteoarthropathy. Management of arthritis in people with cystic fibrosis is uncertain and complex because of the underlying disease and its treatment.

OBJECTIVES

To review the effectiveness and safety of disease-modifying anti-rheumatic drugs (DMARDs) for the management of arthritis related to cystic fibrosis in adults and children.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database handsearches of relevant journal and abstract books of conference proceedings.Date of most recent search: May 2008

SELECTION CRITERIA

Randomised controlled trials which compared the efficacy and safety of DMARDs (e.g. methotrexate, gold, sulfasalazine, penicillamine, leflunomide, hydroxychloroquine and newer agents such as biologic disease modifying agents and monoclonal antibodies) with each other, with no treatment or with placebo for cystic fibrosis-related arthropathy or hypertrophic osteoarthropathy.

DATA COLLECTION AND ANALYSIS

No relevant studies were identified.

MAIN RESULTS

No studies were included in this review.

AUTHORS' CONCLUSIONS

Although it is generally recognised that cystic fibrosis-related arthritis can be episodic and resolve spontaneously, treatment with analgesics and anti-inflammatory agents may be needed. But when episodic symptoms progress to persistent disease, DMARDs may be needed to limit the course of the disease. It is disappointing that no randomised controlled trials to rigorously evaluate DMARDs could be found. This systematic review has identified the need for a well-designed adequately powered randomised controlled trial to assess the efficacy and safety of DMARDs for the management of cystic fibrosis-related arthropathy and hypertrophic osteoarthropathy in adults and children with cystic fibrosis. However, given the infrequency of cystic fibrosis-related arthritis and the range of symptoms and severity, randomised controlled trials may not be feasible and well-designed non-randomised observational studies may be more appropriate. Studies should also better define the two conditions.

Pharmacological agents (anti-inflammatory and analgesic) for managing symptoms in people with cystic fibrosis-related arthritis

BACKGROUND

Arthritis remains a relatively infrequent complication of cystic fibrosis, but is a cause of significant morbidity when it does occur. Two distinct types of arthritis are described in cystic fibrosis: cystic fibrosis-related arthropathy (CFA) and hypertrophic pulmonary osteoarthropathy (HPO). Management of arthritis in people with cystic fibrosis is uncertain and complex because of the underlying disease and its intense treatment.

OBJECTIVES

To review the effectiveness and safety of pharmacological agents for the symptomatic management of cystic fibrosis-related arthritis in adults and children with cystic fibrosis.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings. Date of most recent search: September 2007.

SELECTION CRITERIA

Randomised controlled trials which compared the efficacy and safety of anti-inflammatory and analgesic agents (e.g. non-steroidal anti-inflammatory agents, systemic corticosteroids, intra-articular corticosteroids) with each other, with no treatment or with placebo for CFA and HPO.

DATA COLLECTION AND ANALYSIS

No relevant studies were identified.

MAIN RESULTS

No studies were included in this review.

AUTHORS' CONCLUSIONS

Although it is generally recognised that CFA may be episodic and resolve spontaneously, treatment with analgesics and anti-inflammatory agents may be needed. While this approach may be sufficient to manage symptoms, it is disappointing that no randomised controlled trials to rigorously evaluate these agents were found, nor could the authors identify any quasi-randomised. This systematic review has identified the need for a well-designed adequately-powered randomised controlled trial to assess the efficacy and safety of pharmacological agents for the symptomatic management of cystic fibrosis-related arthritis (CFA and HPO) in adults and children with cystic fibrosis. Studies should also better define the two conditions. A study has recently been conducted in CFA and may help fill this gap when analysed and published.

The use of macrolide antibiotics in patients with cystic fibrosis

PURPOSE OF REVIEW

There has been much recent interest in the use of macrolide antibiotics as chronic suppressive therapy in patients with cystic fibrosis. Three recent randomized, placebo-controlled trials have been conducted.

RECENT FINDINGS

All three trials used similar regimens of azithromycin, and lung function improved after 3 to 6 months of treatment. The relative change in forced expiratory volume in 1 second predicted improved between 3.6% and 6.2%. Furthermore, the azithromycin treatment groups had improvement in a variety of secondary outcomes related to pulmonary exacerbations, including a reduction in antibiotic use (both intravenous and oral) and hospitalization rate. Furthermore, azithromycin was well tolerated: Only nausea, diarrhea, and wheezing (described as mild to moderate) occurred more frequently in the azithromycin group compared with the placebo group. The evidence for the clinical benefit of azithromycin in cystic fibrosis has been summarized in a Cochrane review in which a meta-analysis confirmed a significant improvement in forced expiratory volume in 1 second among the 286 pooled participants.

SUMMARY

Azithromycin has entered the therapeutic armamentarium for patients with cystic fibrosis who are chronically infected with Pseudomonas aeruginosa. Improved lung function, a reduction in pulmonary exacerbations and antibiotic use, and weight gain are potential benefits of this drug. Future studies should address the use of azithromycin in other cystic fibrosis patient populations, including those patients without chronic infection with P. aeruginosa, children younger than 6 years of age, and those infected with Burkholderia cepacia complex. The mechanism of action of macrolide antibiotics in cystic fibrosis remains unknown.

Musculoskeletal manifestations in cystic fibrosis

Although bone and joint manifestations are common in children with cystic fibrosis (CF), they have received little attention in adults. As compared to healthy individuals, bone mineral density is low, even with calcium intakes greater than 1500 mg/d. Nevertheless, calcium and phosphate levels in blood and urine are often normal, and vitamin D levels vary. Short stature with a low body mass index and central hypogonadism are the rule in these patients. Fractures and kyphosis are often reported. CF arthropathy occurs in 2-8.5% of patients. Arthritis develops, and there may be skin eruptions. Non-steroidal antiinflammatory drug therapy is effective. Hypertrophic osteoarthropathy associated with respiratory failure is present in 2-7% of patients. Rheumatoid arthritis, spondyloarthropathies, sarcoidosis, and amyloidosis have been reported in association with CF. Knee pain due to patellofemoral syndrome, quinolone-induced arthropathy, and mechanical back pain have been described. Rheumatoid factor titers are higher than in healthy controls, particularly in patients with episodic arthritis. No data are available on antiperinuclear factor or antikeratin antibody titers. Tests for antinuclear antibody are usually negative. Circulating immune complex levels and antibodies to heat shock proteins may be elevated. Antineutrophil cytoplasmic antibody of the bactericidal/permeability-increasing protein (BPI) or azurocidin (AZ) type has been reported, often in high titers (up to 40%).

Pneumomediastinum after dental surgery

A previously healthy woman presented with chest pain and cervical swelling several hours after undergoing surgical removal of third molar teeth. Mediastinal and subcutaneous emphysema was demonstrated by chest X-ray. Air had been introduced under the soft tissue flap by the high-speed turbine drill used to remove the alveolar bone, rather than the air/water syringe. Surgical handpieces that vent the air away from the surgical field should be used during such procedures. The mediastinal and subcutaneous air resolved after oxygen administration.