Joint hypermobility

Yoga as a complementary therapy for rheumatoid arthritis: a case-based review

Rheumatoid arthritis (RA) presents patients with chronic pain and functional limitations due to its autoimmune nature. Despite symptomatic and pharmaceutical interventions, many patients experience inadequate relief, prompting exploration into non-pharmacological approaches such as yoga. This study aims to evaluate the effectiveness of yoga as an adjunctive therapy for RA by examining clinical data from patients experiencing chronic pain and limitations. This study analyzed several clinical cases at the Shymkent City Regional Clinical Hospital. Ten RA patients, irrespective of various demographic factors, were enrolled. Parameters including pain intensity, inflammation activity, systolic blood pressure, joint function, and morning stiffness were assessed to gauge the impact of yoga. The findings demonstrated notable positive changes following a three-month yoga program. These changes encompassed enhanced joint health, reduced pain severity, and decreased disease activity. Particularly noteworthy was the reduction in morning stiffness by an average of 31 min, alongside a decrease in the average pain index from 80 mm to 41.5 mm. The mean RA activity level decreased from 5.8 to 4.7. Furthermore, mean systolic blood pressure decreased by 15.5 mmHg, and mean cholesterol levels decreased from 5.3 mmol/L to 4.8 mmol/L. These results underscore the potential significance of yoga as a supplementary intervention for RA. Yoga practice may enhance patients' quality of life and alleviate disease symptoms. Nevertheless, the study's limited sample size necessitates caution, and further research is warranted to validate these findings.

An investigation of body awareness, fatigue, physical fitness, and musculoskeletal problems in young adults with hypermobility spectrum disorder

BACKGROUND AND OBJECTIVES

Hypermobility Spectrum Disorder (HSD) is associated with excessive joint range of motion and the presence of musculoskeletal symptoms. The objective of this study was to examine body awareness, physical fitness parameters, fatigue levels, and musculoskeletal disorders in young adults with HSD and compare them with those without HSD.

METHODS

Young individuals in the age range of 18-24 years were included in the study. Joint hypermobility of individuals was determined by the Beighton Score. Evaluations were made using the Body Awareness Questionnaire, the Fatigue Severity Scale, the Eurofit Physical Fitness Test Battery, and the Cornell Musculoskeletal Discomfort Questionnaire.

RESULTS

A total of 94 healthy individuals (74 females, 20 males, mean age 21.44 years, SD ± 1.19 years), 47 with HSD and 47 without HSD, were included in the study. It was concluded that body awareness and fatigue levels were similar in two groups (p > 0.05). When physical fitness parameters were examined, there was a significant difference between the two groups in Sit and Reach test and the dominant side grip strength (p < 0.05). There was a significant difference between the two groups in the neck, back, dominant wrist, and total musculoskeletal problems (p < 0.05).

CONCLUSION

It was concluded that young individuals with HSD had more flexibility, lower grip strength, more pain especially in the neck and back region, and more musculoskeletal disorders in general. Joint hypermobility is a factor to be considered in evaluating functional performance in these individuals.

Masterclass: Hypermobility and hypermobility related disorders

INTRODUCTION

Hypermobile joints display a range of movement that is considered excessive, taking into consideration the age, gender and ethnic background of the individual. Joint hypermobility may present in a single joint, a few joints or in multiple joints and may be congenital or acquired with training, disease or injury. Hypermobile joints may be asymptomatic or may be associated with pain, fatigue, multisystemic complaints and significant disability. Furthermore, joint hypermobility may be a sign of an underlying hereditary disorder of connective tissue.

PURPOSE

This masterclass aims to provides a state-of-the-art review of the aetiology, epidemiology, clinical presentation, assessment and management of joint hypermobility and hypermobility related disorders using an evidence based and biopsychosocial approach. The new framework for classifying the spectrum of joint hypermobility disorders along with new diagnostic criteria for the hypermobile Ehlers Danlos syndrome, published by an international consortium of clinical experts and researchers in 2017 is integrated into the paper.

IMPLICATIONS FOR PRACTICE

People with joint hypermobility related disorders present to healthcare professionals with a wide range of symptoms which extend beyond the musculoskeletal system. Early recognition and treatment are key to effective management. A biopsychosocial and patient empowerment approach to functional restoration is recommended.

Hypermobile spectrum disorders symptoms in patients with functional neurological disorders and autism spectrum disorders: A preliminary study

Autism spectrum disorders (ASDs) and functional neurological disorders (FNDs) share some clinical characteristics such as alexithymia, sensory sensitivity and interoceptive issues. Recent evidence shows that both the disorders present symptoms compatible with a diagnosis of hypermobile Ehlers-Danlos Syndrome and hypermobile spectrum disorders (hEDS/HSD), a heterogeneous group of heritable connective tissue disorders characterized by joint hypermobility, skin hyperextensibility, and tissue fragility. Here we compared the prevalence of hEDS/HSD-related symptoms in a group of patients with FNDs, of people with ASDs without intellectual disabilities, and a non-clinical comparison group (NC). Twenty patients with FNDs, 27 individuals with ASDs without intellectual disabilities and 26 NC were recruited and completed the Self-reported screening questionnaire for the assessment of hEDS/HSD-related symptoms (SQ-CH). We found that 55% of the patients with FNDs, 44.4% of the individuals with ASDs and 30.8% of NC scored above the cut-off at the SQ-CH; SQ-CH scores of both FNDs and ASDs group were significantly higher than the NC group's ones. In conclusion, both ASDs and FNDs individuals present hEDS/HSD-related symptoms in a higher number than the general population. Imputable mechanisms include (i) overwhelming of executive functions with consequent motor competence impairment for ASDs individuals, and (ii) exacerbation of FNDs symptoms by physical injury and chronic pain due to abnormal range of joint mobility. Moreover, we speculated that the amygdala and the anterior cingulate cortex circuitry might be responsible for the imbalances at the proprioceptive, interoceptive, and emotional levels.

Physical and mechanical therapies for lower limb symptoms in children with Hypermobility Spectrum Disorder and Hypermobile Ehlers-Danlos Syndrome: a systematic review

Background

Hypermobility Spectrum Disorder and Hypermobile Ehlers Danlos Syndrome are two common heritable genetic disorders of connective tissue. Both conditions are characterised by excessive joint range of motion and the presence of musculoskeletal symptoms, and are associated with joint instability, motion incoordination, decreased joint position sense, and musculoskeletal pain. Hypermobility Spectrum Disorder is the new classification for what was previously known as Joint Hypermobility Syndrome. This systematic review evaluates the evidence for physical and mechanical treatments for lower limb problems in children with Hypermobility Spectrum Disorder and Hypermobile Ehlers Danlos Syndrome.

Methods

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, PUBMED and CINAHL were searched to October 2017 for randomised controlled trials (RCT) and quasi-RCTs evaluating physical and mechanical interventions for lower limb problems in children with hypermobility. Two authors independently screened studies for eligibility for inclusion and three review authors independently assessed risk of bias of included studies. One author extracted and analysed statistical data, which were checked by a second author.

Results

Two RCTs including a total of 86 participants were eligible for inclusion. Trials evaluated differences between generalised versus targeted physiotherapy programs and between performing knee extension exercises to the neutral versus hypermobile range. There was no clear benefit of any of the physical therapies evaluated.

Conclusion

There is very limited evidence to guide the use of physical and mechanical therapies for lower limb problems in children with Hypermobility Spectrum Disorder and Hypermobile Ehlers Danlos Syndrome. Mechanical therapies have not been evaluated in RCTs and results of the two RCTs of physical therapies do not definitively guide physical therapy prescriptions. Current studies are limited by small sample sizes and high attrition rates. No physical therapy has been compared to a sham intervention no intervention or no intervention, so overall effectiveness is unknown.

Range of Ankle Dorsiflexion in a Group of Adults with Ligamentous Laxity

BACKGROUND

Ligamentous or joint laxity is a clinical entity characterized by increased joint mobility beyond the range of motion regarded as normal, and joint mobility is an effective indicator of the degree of laxity. We examined the influence of ligamentous laxity on the range of ankle dorsiflexion with the knee flexed and extended, comparing lax adults with a control (nonlax) group.

METHODS

The sample comprised 400 individuals: 200 in the control group (mean ± SD age, 32.49 ± 11.06 years) and 200 in the lax group (mean ± SD age, 29.82 ± 9.40 years). The Beighton criteria were applied to each participant to diagnose laxity or nonlaxity, and sex, age, and angle range of bilateral dorsiflexion with the knee extended and flexed were recorded.

RESULTS

The mean ± SD dorsiflexion range with the knee straight was 16.14° ± 5.29° left ankle and 21.21° ± 4.93° right ankle in the lax group and 12.94° ± 4.17° left ankle and 17.08° ± 4.40° right ankle in the control group. The respective values with the knee flexed were 15.84° ± 5.31° and 21.21° ± 4.80° in the lax group and 12.95° ± 3.95 and 17.23° ± 4.25° in the control group.

CONCLUSIONS

In this sample, ankle dorsiflexion range in the lax group was 4° bigger than that in the control group in both knee positions.

Managing the patient with osteogenesis imperfecta: a multidisciplinary approach

Osteogenesis imperfecta (OI) is a heterogeneous heritable connective tissue disorder characterized by low bone density. The type and severity of OI are variable. The primary manifestations are fractures, bone deformity, and bone pain, resulting in reduced mobility and function to complete everyday tasks. OI affects not only the physical but also the social and emotional well-being of children, young people, and their families. As such, medical, surgical, and allied health professionals’ assessments all play a role in the management of these children. The multidisciplinary approach to the treatment of children and young people living with OI seeks to provide well-coordinated, comprehensive assessments, and interventions that place the child and family at the very center of their care. The coordinated efforts of a multidisciplinary team can support children with OI to fulfill their potential, maximizing function, independence, and well-being.

Increased joint pain after massive weight loss: is there an association with joint hypermobility?

BACKGROUND

Obesity is associated with an increased risk of pain in weight-bearing joints. Although pain often decreases after obesity surgery, this is the reverse for some patients. Hypermobility is described as an excessive range of motion in joints and has been suggested to be a possible cause of joint pain. It is not known whether there is an association between increased joint pain after weight loss and hypermobility.

OBJECTIVES

The objective of this study was to investigate whether there is an association between hypermobility and increased joint pain after massive weight loss.

SETTING

University hospital, Sweden.

METHODS

A survey including a screening questionnaire about hypermobility and questions about joint pain was sent to 149 people who had previously undergone bariatric surgery. Ninety-three people (72 women and 21 men) completed the questionnaire.

RESULTS

Nineteen of the respondents fulfilled the criteria for hypermobility. There were no significant differences between the groups with and without hypermobility regarding pain in weight-bearing joints before or after surgery. There was a significant difference between the groups with increased or novel pain in the ankles, shoulders, hands, and feet (P<.05) after the weight loss. Furthermore, the patients with hypermobility had increased or novel pain in a significantly higher number of weight-bearing joints, other joints, and joints in total (P< .05).

CONCLUSION

Even with a small sample size, a tendency can be seen for people with hypermobility to experience increased joint pain after weight loss compared with those without hypermobility.

Adolescent obesity, joint pain, and hypermobility

BACKGROUND

Obesity associated with joint pain of the lower extremities is likely due to excessive mechanical load on weight bearing joints. Additional mechanical factors may explain the association between obesity and joint pain.

FINDINGS

We characterized the association between obesity and non-traumatic lower extremity (LE) joint pain in adolescents and examined the modifying effect of hypermobility on this association.We performed a cross-sectional analysis of data from subjects enrolled in a clinical trial examining the impact of weight loss on bone health in adolescents. Anthropometric data were collected and body mass index (BMI = kg/m2) was calculated. Subjects were categorized as obese or healthy weight controls based on CDC 2000 growth curves for age and gender. We assessed any musculoskeletal pain and LE pain by the PEDS™ Pediatric Pain Questionnaire™. Hypermobility was assessed with the modified Beighton scoring system. Multivariate logistic regression models adjusted for covariates were performed to examine the association between weight status and joint pain.Out of 142 subjects, 91 were obese and 51 were healthy weight. Obesity was not associated with any musculoskeletal pain (OR 0.86, CI 0.49-1.50), LE pain (OR 1.02, CI 0.49-2.15) or hypermobility (OR 1.23, CI 0.72-2.14, p = 0.3). There was no effect modification on the association between obesity and any musculoskeletal pain (OR 0.80, CI 0.45 -1.42) or LE pain (OR 0.98, CI 0.46 - 2.08) by hypermobility status.

CONCLUSIONS

We found no association between LE pain and obesity, and hypermobility did not modify this association.

Serum prolidase activity in benign joint hypermobility syndrome

BACKGROUND

Moderate joint laxity is widespread in many joints of the body, and this condition is considered to be caused by an abnormality in the collagen structure. This study was carried out to determine the serum prolidase activity in female patients with benign joint hypermobility syndrome (BJHS), and to evaluate its correlation with their clinical features.

METHODS

A total of 45 patients with BJHS and 40 healthy controls were included in the study. All of the patients with BJHS met the Beighton diagnostic criteria. All the patients and the control group underwent a comprehensive examination of the locomotor system and took the New York Posture Rating Test. The examination and test results were recorded. Serum prolidase activity was measured in both the groups.

RESULTS

Prolidase activity was significantly lower in patients with BJHS (479.52 ± 126.50) compared to the healthy controls (555.97 ± 128.77) (p = 0.007). We found no correlation between serum prolidase activity and Beighton scores or New York rating test scores. On the other hand, mean prolidase activity was significantly lower in patients with pes planus or hyperlordosis compared to those without (p = 0.05, p = 0.03, respectively). We did not find such a correlation with the other clinical features.

CONCLUSIONS

Significantly lower prolidase activity in patients with BJHS suggests that prolidase may affect the collagen metabolism and cause hyperlaxity.

Health supervision for children with Marfan syndrome

Marfan syndrome is a systemic, heritable connective tissue disorder that affects many different organ systems and is best managed by using a multidisciplinary approach. The guidance in this report is designed to assist the pediatrician in recognizing the features of Marfan syndrome as well as caring for the individual with this disorder.

Tai Chi and yoga as complementary therapies in rheumatologic conditions

Tai Chi and yoga are complementary therapies which have, during the last few decades, emerged as popular treatments for rheumatologic and musculoskeletal diseases. This review covers the evidence of Tai Chi and yoga in the management of rheumatologic diseases, especially osteoarthritis of the knee, hip and hand, and rheumatoid arthritis. There is evidence that Tai Chi and yoga are safe, and some evidence that they have benefit, leading to reduction of pain and improvement of physical function and quality of life in patients. Recommendations for Tai Chi in knee osteoarthritis have recently been issued by the American College of Rheumatology. To allow broader recommendations for the use of Tai Chi and yoga in rheumatic diseases, there is a need to collect more evidence researched with larger randomised controlled trials.

Association of hypermobility and ingrown nails

Ingrown nail (onychocryptosis) is a common condition with severe pain and various associated morbidities. Although some underlying factors are identified, its etiology remains largely unknown. Generalized joint hypermobility (GJH) is a common entity with clinical features that might prone affected individuals to ingrown nails. Herein, we investigated the incidence of GJH in patients with ingrown nails to determine possible association between hypermobility and ingrown nail formation. Patients 16-50 years of age who were undergoing treatment for ingrown nails at the dermatology clinic were consecutively enrolled into the study. Patients with known rheumatic diseases or orthopedic foot disorders were excluded. All patients were in a pain-free period at the time of examination. The control group was comprised of age- and sex-matched healthy subjects without a history of ingrown nail. Assessment of GJH was made according to Beighton criteria. Local hypermobility was evaluated by measurement of range of motion using a goniometer. Thirty-nine patients (male/female, 17/22, mean age 31.9 ± 11.3 years) and 32 healthy subjects (male/female 12/20, mean age 31.7 ± 10.4 years) were included. Patients with ingrown toe nails were more likely to have GJH compared to healthy subjects (35.9 vs. 9.4 %, p = 0.009). Toes with ingrown nails had significantly smaller maximum dorsiflexion angles (p < 0.001) compared to toes of healthy subjects. Ingrown nail formation may be associated with GJH. However, when examined locally, there is a limited range of motion in the affected toe rather than hypermobility, which could be due to the degenerative process facilitated by the hypermobility.

Lumbar artificial disc replacement in Ehlers-Danlos syndrome: A case report and discussion of clinical management

Background

Ehlers-Danlos syndrome (EDS) is a heterogeneous collection of connective tissue disorders characterized by varying degrees of skin hyperextensibility, joint hypermobility, and tissue fragility. Surgical treatment of EDS patients is complicated by the extreme fragility of their vessels and tissues. The purpose of this case report is to present the management of an EDS patient with debilitating low-back pain.

Methods

A 52-year-old woman with a clinical diagnosis of EDS presented with degenerative disc disease at L4-5 that had not been alleviated by previous microdiscectomies. The clinical course, decision-making process, and treatment are discussed in this case report.

Results

The patient was referred for genetic evaluation, which classified her with type III EDS, or hypermobility type. We presented the patient with the risks and benefits of fusion versus artificial disc replacement (ADR), particularly with regard to her EDS diagnosis of the hypermobility subtype. Given the patient's lack of extreme spinal hypermobility on examination and the absence of clear contraindications regarding ADR in type III EDS, the decision was made to proceed with ADR. There were no surgical complications, and the patient's low-back pain and radicular symptoms resolved with no evidence of implant migration or hypermobility at 1 year postoperatively.

Conclusions

In this case report, the referral to a geneticist and consultation with a vascular surgeon were integral steps in the decision to proceed with surgery. Although the clarified diagnosis of type III EDS did not eliminate the potential risk for vascular compromise during surgery, it placed the patient at lower risk than patients with other subtypes of EDS. Similarly, her lack of extreme hypermobility made us more comfortable with pursuing ADR. Although we emphasize extreme caution when considering surgical treatment, this case report suggests that some patients with less severe forms of EDS may be able to successfully undergo anterior spine surgery, including ADR.

Gait kinematics and passive knee joint range of motion in children with hypermobility syndrome

Hypermobility syndrome (HMS) is characterised by generalised joint laxity and musculoskeletal complaints. Gait abnormalities have been reported in children with HMS but have not been empirically investigated. The extent of passive knee joint range of motion (ROM) has also not been well reported in children with HMS. This study evaluated gait kinematics and passive knee joint ROM in children diagnosed with HMS and healthy controls. Thirty-seven healthy children (mean age±SD=11.5±2.6 years) and 29 children with HMS (mean age±SD=11.9±1.8 years) participated. Sagittal knee motion and gait speed were evaluated using a VICON 3D motion analysis system. Passive knee ROM was measured with a manual goniometer. Independent t-tests compared the values of sagittal knee motion and gait speed between the two groups. Mann-Whitney U tests compared passive knee ROM between groups. Passive ROM (extension and flexion) was significantly higher (both p<0.001) in children with HMS than the healthy controls. Peak knee flexion (during loading response and swing phase) during walking was significantly lower (both p<0.001) in children with HMS. Knee extension in mid stance during walking was significantly increased (p<0.001) in children with HMS. However, gait speed was not statistically (p=0.496) different between the two groups. Children with HMS had higher passive knee ROM than healthy children and also demonstrated abnormal knee motion during gait. Gait re-education and joint stability exercise programmes may be of value to children with HMS.

An exploration of the prevalence of hypermobility and joint hypermobility syndrome in Omani women attending a hospital physiotherapy service

BACKGROUND AND OBJECTIVES

Joint hypermobility syndrome (JHS) is an inherited disorder of connective tissue. It presents as a condition in which there are neuromusculoskeletal signs and symptoms, including pain, without the inflammatory component of a joint disease such as rheumatoid arthritis. Re-attendance in rheumatology clinics, re-injury and prolonged rehabilitation are also features of JHS. The primary aims of this study were to establish the prevalence of hypermobility and JHS in those attending physiotherapy clinics with neuromusculoskeletal disorders in Oman.

METHODS

A cross-sectional case control study design was used. The participant population included Omani women, aged 18-50 years, attending physiotherapy services for musculoskeletal complaints. The comparison population comprised women of a similar age and ethnic origin who were staff at the hospital. The primary outcome measures were the Beighton Score and the Brighton Criteria.

RESULTS

A total of 184 subjects were recruited into the study. These consisted of 94 in the participant group and 90 in the comparison group. Hypermobility was recorded in 51% of the participant group and 30% of the comparison group. The number of participants with JHS was 55%, while 21% of the comparison group exhibited features of the JHS phenotype without pain. A significant number of participants with JHS were re-attending for treatment compared with those without JHS.

CONCLUSIONS

This study confirms a high prevalence of JHS among subjects with musculoskeletal signs and symptoms and that re-attendance for physiotherapy treatment is more frequent in subjects with JHS than in those without.

Pain intensity and quality of life perception in children with hypermobility syndrome

Hypermobility syndrome (HMS) is a major source of morbidity in children. Impaired quality of life (QoL) has been observed recently in adults with HMS; however, this issue is yet to be investigated in children with this condition. This study compared pain intensity and QoL in children with HMS with healthy controls. It also examined the relationship between pain intensity and QoL in children with HMS. Following ethical approval, 29 children diagnosed with HMS and 37 healthy children aged 8-15 years participated. Informed written consent was obtained from participants and their parents/guardians. Average knee pain over the past week was examined using the Coloured Analogue Scale. QoL was measured via the Pediatric Quality of Life Inventory. Mann-Whitney U tests were performed to compare pain and QoL scores between the two groups. Spearman Rho correlation analysis was performed to examine the relationship between pain and QoL. Overall QoL scores in each domain were significantly lower in children with HMS (all p < 0.001) compared with the controls. Pain intensity was significantly higher in children with HMS compared with their healthy counterparts (p < 0.001). A strong negative correlation was observed between pain intensity and overall QoL and all the domains (r range = -0.614 to -0.717; all p < 0.001). In conclusion, the findings of the present study imply that pain and QoL assessment might form important components of clinical examination for children diagnosed with HMS. These children may benefit from appropriate treatment programmes to alleviate pain intensity and improve QoL.

A Novelin VivoSkin Extensibility Test for Joint Hypermobility

Objective.

The stress/strain curve derived from stretching skin is not linear, but follows a J-shaped curve. An initial generous yield is followed by a steep linear phase where considerable additional force is required to achieve modest increases in deformation. The former represents the taking up of slack resulting from the alignment of dermal collagen bundles in the line of force, while the gradient of the latter represents Young’s modulus for skin. Skin hyperextensibility in Ehlers-Danlos syndrome (EDS) is limited to the initial phase of taking up slack. Skin hyperextensibility and joint hypermobility (JHM) form part of the Revised 1998 Brighton diagnostic criteria for the benign joint hypermobility syndrome (BJHS), considered by many to be akin to EDS-hypermobility type. JHM may be screened for using the Beighton Score or a 5-point questionnaire. Our aim was to validate a novel method of measuring skin extensibility based on these observations in addition to revalidating the 5-point questionnaire.

Methods.

250 volunteers (131 female), median age 39 years (range 18–89 yrs), without BJHS, had their joint mobility evaluated using the Beighton Score, compared to the 5-point questionnaire. A Beighton score ≥ 4/9 was considered to represent JHM. Skin extensibility was determined by placing 2 dots on the dorsum of the right hand between the second and third metacarpals, approximately 10 mm apart, and was measured using an electronic caliper. Perpendicular to the metacarpals, a force was applied until the skin was fully taut and the increment was measured. Skin-fold thickness was measured using a Harpenden caliper. A corrected skin extensibility score (CSES) was calculated by dividing the percentage increment by skin thickness. Interobserver variability was measured in a further 50 healthy volunteers.

Results.

The prevalence of JHM was 17.6%. Revalidation of the 5-point questionnaire returned a sensitivity of 0.85 and specificity of 0.85. The mean CSES was 23.84%/mm in the hypermobile group versus 13.55%/mm in the normal mobility group (p < 0.0001). CSES sensitivity was 0.72, specificity 0.75. The κ value for interobserver variability was 0.83.

Conclusion.

The CSES is a useful and reproducible measure of skin extensibility in health. Further work is warranted to validate this test in patients with BJHS.

Hemarthrosis due to a rare cause of hemorrhagic diathesis: Ehlers-Danlos syndrome

The authors report a case of hemarthrosis complicated by severe anemia related to a congenital connective tissue disease: Ehlers-Danlos syndrome. A boy fell down and suffered tumefaction of both knees with bilateral rupture of the rotula tendon. He underwent surgical reinsertion of each tendon on the rotula. He later showed an unexpected ongoing hematic effusion, with severe anemia. He was screened for coagulation disorders with no results. On taking a more detailed history and investigating the patient's phenotypical features, the authors diagnosed Ehlers-Danlos syndrome, hypermobile variant. The hemarthrosis and anemia were thus concluded to be consequences of excessive tissue fragility due to a congenital connective tissue disease.