Relapsing polychondritis

# Overview
Relapsing polychondritis is an immune-mediated chronic disease which involves the cartilaginous structure of different parts of the body, most commonly those of the ears, nose, and laryngotracheobronchial tree. The term relapsing polychondritis was first coined by Pearson in 1960. The majority of patients with relapsing polychondritis remain asymptomatic for several years. Early clinical features include ear pain, polyarthritis and other non-specific symptoms such as fever, weight loss and skin rash. The pathogenesis of relapsing polychondritis is unknown, however several studies have suggested the role of both cellular immunity and abnormal autoantibody in the pathogenesis of relapsing polychondritis. There are two different criteria to diagnose relapsing polychondritis which include Mc Adam criteria and modified Damiani criteria. There are no specific laboratory findings associated with relapsing polychondritis but certain antibodies are raised such as anti-type II collagen antibodies and antineutrophil cytoplasmic antibodies. Other abnormal laboratory findings include low haemoglobin, leukocytosis, eosinophilia, increased ESR, CRP, urinary glycosaminoglycans levels and urinary collagen type II neoepitope levels in active inflammation. Imaging such as chest x-ray is helpful to find out tracheal stenosis, however, CT scan is more useful to diagnose subglottic stenosis. MRI is useful to see the difference between edema, fibrosis, and inflammation. The mainstay of therapy for relapsing polychondritis is medical therapy. NSAIDs are used as an initial treatment of relapsing polychondritis. If NSAIDs are contraindicated or resistant, then steroids or dapsone can be used. Prednisone is used in the treatment of relapse. Treatment of life-threatening organ damage include prednisone and cyclophosphamide. Various surgical options include tracheostomy, cardiac valve replacement, aortic aneurysm repair, and saddle-nose deformity repair.

# Historical Perspective
- In 1923, Jaksch-Wartenhorst used the term polychondropathia to describe his first case about relapsing polychondritis.
- In 1960, the term relapsing polychondritis was first coined by Pearson.

# Classification
- There is no established classification of relapsing polychondritis.

# Pathophysiology
- The pathogenesis of relapsing polychondritis is unknown.
- Several studies have suggested the role of both cellular immunity and abnormal autoantibody in the pathogenesis of relapsing polychondritis.
- The HLA class II has been associated with the development of relapsing polychondritis, there is increase susceptibility with HLA-DR4.
- On gross pathology, thickening of cartilage of ear, nose, epiglottis, and cricoid and tracheal rings are characteristic findings of relapsing polychondritis.
- On microscopic histopathological analysis of relapsing polychondritis, following features are seen:
Lymphocytes, plasma cells, neutrophils, and  eosinophils are seen in the cartilage.
Cartilage has lost the chondrocytes and normal architecture at the later stages of inflammation.
Cartilage is replaced by fibrous tissue in the end.
- Lymphocytes, plasma cells, neutrophils, and  eosinophils are seen in the cartilage.
- Cartilage has lost the chondrocytes and normal architecture at the later stages of inflammation.
- Cartilage is replaced by fibrous tissue in the end.

# Differentiating Relapsing Polychondritis from other Diseases
- Chondritis
- Chondromdermatitis
- Hansen's disease
- Nodularis helicis
- Perichondritis
- Rhinophyma
- Skin cancer
- Syphilis
Also, Relapsing Polychondritis should be differenttieted form other causes of small-sized vessel vasculitis.
Abbreviations:
ABG= Arterial blood gas, ANA= Antinuclear antibody, ANP= Atrial natriuretic peptide, ASO= Antistreptolysin O antibody, BNP= Brain natriuretic peptide, CBC= Complete blood count, COPD= Chronic obstructive pulmonary disease, CRP= C-reactive protein, CT= Computed tomography, CXR= Chest X-ray, DVT= Deep vein thrombosis, ESR= Erythrocyte sedimentation rate, HRCT= High Resolution CT, IgE= Immunoglobulin E, LDH= Lactate dehydrogenase, PCWP= Pulmonary capillary wedge pressure, PCR= Polymerase chain reaction, PFT= Pulmonary function test.

# Epidemiology and Demographics
- The  incidence of relapsing polychondritis is approximately 4 per 100,000 individuals in Minnesota.

## Age
- Relapsing polychondritis is more commonly observed among patients aged 40 to 60 years but it can also occur in childhood.

## Gender
- Relapsing polychondritis affects men and women equally.

## Race
- Relapsing polychondritis usually affects Caucasian.

# Risk Factors
Common risk factors in the development of relapsing polychondritis include:
- Genetic susceptibility:
Increased risk with HLA DR4
- Increased risk with HLA DR4
- History of other connective tissue disorders

# Natural History, Complications and Prognosis
- The majority of patients with relapsing polychondritis remain asymptomatic for several years.
- Early clinical features include ear pain, polyarthritis and other non-specific symptoms such as fever, weight loss and skin rash.
- Common complications of relapsing polychondritis include collapsing of cartilage which causes facial abnormalities, deformities of the ear, eye, and destruction of the thyroid gland.
- Relapsing polychondritis has the relapsing and remitting course, Prognosis depends upon the type of organ involvement, stage of the disease.

# Diagnosis

## Diagnostic Criteria
According to modified Damiani criteria, there should be one of the following findings to diagnose relapsing polychondritis:
- There should be three of McAdam's diagnostic criteria.
- One or more of the clinical findings of McAdam's diagnostic criteria and positive histologic confirmation.
- Chondritis at two or more separate anatomic locations with a response to glucocorticoids or dapsone.

## Symptoms
Symptoms of relapsing polychondritis may include the following:
- Ear pain
- Eye pain, redness, and increased lacrimation
- Decreased visual acuity
- Proptosis
- Rhinorrhea
- Epistaxis
- Pain on the movement of joint
- Joint swelling
- Cough
- Shortness of breath
- Dysphagia
- Chest pain
- Headache
- Confusion

## Physical Examination
- Patients with relapsing polychondritis usually appear lethargic.
- Physical examination may be remarkable for:
- Ear examination:
On inspection, there is inflammation and swelling
On palpation, there is tenderness
- On inspection, there is inflammation and swelling
- On palpation, there is tenderness
- Eye examination:
On inspection, lid retraction, redness of the eye, ptosis, and proptosis
Visual acuity is decreased
- On inspection, lid retraction, redness of the eye, ptosis, and proptosis
- Visual acuity is decreased
- Lung examination:
On auscultation, wheezing and expiratory stridor is found
- On auscultation, wheezing and expiratory stridor is found
- Heart examination:
S1, S2 is normal, the murmur can be heard depending on the involvement of valve
- S1, S2 is normal, the murmur can be heard depending on the involvement of valve
- Joint examination:
On inspection, there is redness and swelling
On palpation, there is tenderness
- On inspection, there is redness and swelling
- On palpation, there is tenderness

## Laboratory Findings
- There are no specific laboratory findings associated with relapsing polychondritis.
- Abnormal laboratory findings consistent with the diagnosis of relapsing polychondritis include:
CBC with differentials
Low hemoglobin
Leukocytosis
Eosinophilia
ESR and CRP are usually raised
Antibody testing
Anti-type II collagen antibodies is usually raised in early phase of disease
Antineutrophil cytoplasmic antibodies is found in patients who has vasculitis
Urinary glycosaminoglycans levels may be elevated
Urinary collagen type II neoepitope levels is elevated in active inflammation
Levels of urinary collagen type II neoepitope is used to assess response to treatment
Serum levels of cartilage oligomeric matrix protein is elevated and used as a marker of disease activity
- CBC with differentials
Low hemoglobin
Leukocytosis
Eosinophilia
- Low hemoglobin
- Leukocytosis
- Eosinophilia
- ESR and CRP are usually raised
- Antibody testing
Anti-type II collagen antibodies is usually raised in early phase of disease
Antineutrophil cytoplasmic antibodies is found in patients who has vasculitis
- Anti-type II collagen antibodies is usually raised in early phase of disease
- Antineutrophil cytoplasmic antibodies is found in patients who has vasculitis
- Urinary glycosaminoglycans levels may be elevated
- Urinary collagen type II neoepitope levels is elevated in active inflammation
Levels of urinary collagen type II neoepitope is used to assess response to treatment
- Levels of urinary collagen type II neoepitope is used to assess response to treatment
- Serum levels of cartilage oligomeric matrix protein is elevated and used as a marker of disease activity

## Imaging Findings
- X-ray of the chest shows tracheal stenosis.
- CT scan of the chest shows following findings:
Subglottic stenosis
Thickening of anterior and lateral tracheal wall with sparing of the posterior membranous wall
- Subglottic stenosis
- Thickening of anterior and lateral tracheal wall with sparing of the posterior membranous wall
- MRI is better than CT scanning to see the difference between edema, fibrosis, and inflammation

# Other Diagnostic studies
- ECG and Echocardiography are done in the patient who has cardiac involvement.
- Bronchoscopy used to visualize extensive disease involving the lungs.

# Treatment

## Medical Therapy
- The mainstay of therapy for relapsing polychondritis is medical therapy.
- NSAIDs are used as an initial treatment of relapsing polychondritis.
- Preferred regimen: Naproxen 500 mg PO q12h or ibuprofen 800 mg PO q6h x 7 to 10 days.
- If NSAIDs are contraindicated or resistant then following regimens are used:
Preferred regimen: Dapsone 50 to 100 mg PO q24h x 4 months depending on the severity of the disease.
Preferred regimen: Prednisone 30 to 60 mg PO q24h in divided dose.
- Preferred regimen: Dapsone 50 to 100 mg PO q24h x 4 months depending on the severity of the disease.
- Preferred regimen: Prednisone 30 to 60 mg PO q24h in divided dose.
Treatment of relapse:
- Preferred regimen: Prednisone 5 to 7.5 mg PO q24h
Treatment of life-threatening organ damage:
- Preferred regimen: Initial therapy is the combination of prednisone 1 mg/kg PO q24h and cyclophosphamide 2 mg/kg PO q24h.
- Maintenance therapy depends on the renal function of a patient.
- Patient without nephritis, Preferred regimen: Methotrexate 15mg PO once weekly.
- Patient with nephritis, Preferred regimen: Azathioprine - dose is adjused according to GFR.

## Surgery
Medical therapy is the mainstay of therapy for relapsing polychondritis, however various surgical options include:
- Tracheostomy
- Cardiac valve replacement
- Aortic aneurysm repair
- Saddle-nose deformity repair

## Prevention
There are no primary preventive measures available for relapsing polychondritis.