Mixed Connective Tissue Disease
Mixed connective tissue disease is a disorder of the skin, tendons, and bones that can be a cause of serious pain. Although its origins are unclear, it is thought to be a result of a genetic mutation. Symptoms include inflammation, swelling, and scarring of the affected area. If left untreated, the condition can lead to joint deterioration and amputation. Affected people may also experience psychological and social issues as a result of their condition.
Symptoms
Mixed connective tissue disease is a rare autoimmune condition that involves an abnormal reaction of the immune system. This causes inflammation of various body parts, such as the joints, lungs, heart, and brain.
While the exact causes of mixed connective tissue disease are unknown, it may be caused by exposure to certain chemicals or viruses. People with MCTD are monitored closely by doctors, who try to prevent complications. If the disease does become severe, stronger treatment may be necessary. Depending on the severity of the disease, treatment can include taking antimalarial or nonsteroidal anti-inflammatory drugs.
In the early stages of mixed connective tissue disease, the most common symptoms are swelling of the hands, which may be accompanied by tenderness and muscle weakness. Over time, the fingers and knuckles can become sausage-like. Other symptoms of MCTD include joint pain, fevers, and fatigue.
During the more advanced stages of the disease, the lungs and kidneys may be affected. Pulmonary hypertension, the main cause of death in people with MCTD, is also common. It causes problems with breathing, especially during exercise.
Another symptom of mixed connective tissue disease is the development of scleroderma, a thickening and hardening of the skin. Scleroderma can be life-threatening, as it can result in tissue death. Sjogren’s syndrome is another symptom of mixed connective tissue disease, as it can cause problems with the trigeminal nerve.
Those with MCTD can develop other rheumatic diseases, such as systemic lupus erythematosus. In a small study, a link was found between MCTD and hearing loss.
People with MCTD are advised to follow a proper diet and exercise. They should also join a support group to learn more about their condition and get advice from other patients.
Treatment for MCTD may include corticosteroids, which can help to control the symptoms of the disease. However, they can cause other negative side effects, including weight gain, high blood pressure, and weakened bones.
Most people with MCTD have no cure. The condition usually peaks in adolescence and continues to worsen over time. But treatment is usually effective, and some patients can experience long remissions.
Diagnosis
Mixed connective tissue disease (MCTD) is an autoimmune disorder, meaning that the immune system mistakes healthy cells for harmful ones and attacks them. People with MCTD may have a high risk of developing cardiovascular conditions such as atherosclerosis.
Symptoms of mixed connective tissue disease can vary but usually include muscle weakness and pain. It can also cause problems with the joints. The heart, lungs, and kidneys can also be affected. Some people with MCTD have a family history of the disease.
Mixed connective tissue disease is diagnosed based on the symptoms that appear and on the results of blood tests. Several different antibodies can be present in patients with mixed connective tissue disease, including ribonucleoprotein antibodies. These antinuclear antibodies can be found in other connective tissue diseases, as well.
A definitive diagnosis of mixed connective tissue disease requires a detailed examination of the patient. This includes taking a history of symptoms, performing a physical exam, and identifying characteristic changes in laboratory findings.
Most people with mixed connective tissue disease are female. They have symptoms that are similar to those of rheumatoid arthritis and systemic lupus erythematosus. While most cases of MCTD are mild, they can lead to complications such as pulmonary hypertension and heart failure. Approximately 40 per cent of patients with MCTD have pericarditis.
Many people with mixed connective tissue disease are able to control their condition with nonsteroidal anti-inflammatory drugs and antimalarial drugs. However, in more severe cases, immunosuppressive drugs are used. In this case, the disease is often treated with larger doses of corticosteroids. Corticosteroids can cause weight gain and high blood pressure, as well as cataracts.
A rheumatology specialist can be helpful in diagnosing and treating MCTD. For instance, a doctor may use an electromyogram to analyze the electrical activity of the muscles. Another common test is a muscle biopsy. This involves removing a small amount of tissue from the muscle and looking at it under a microscope.
While there is no cure for mixed connective tissue disease, treatment varies based on the severity of the illness. Nonsteroidal anti-inflammatory drugs and corticosteroids are the most effective therapies. Patients with MCTD should work with a rheumatology specialist to develop a long-term plan of care.
Treatment
Mixed connective tissue disease (MCTD) is a type of autoimmune disease. MCTD causes inflammation of the tissues and swollen joints. The condition can also lead to complications affecting the heart, kidneys, and lungs.
Symptoms of mixed connective tissue disease are similar to those of lupus or systemic sclerosis. Depending on the severity of the condition, treatment may be required. However, MCTD has no known cure. Nonetheless, it can be controlled with a variety of treatments. These therapies target the activities of the disease and its symptoms. Ultimately, the goal is to control the signs and symptoms and reduce the risk of future complications.
Patients with MCTD are typically treated by primary care physicians. In some cases, specialists are also involved. During a physical exam, the physician will examine the patient’s symptoms and blood test results to determine the cause of the disease.
Treatment for MCTD includes immunosuppressive agents. Immunosuppressive medications help suppress inflammation in the affected tissues. They can be administered using corticosteroids, nonsteroidal anti-inflammatory drugs, or antimalarials. If the inflammation is severe, higher doses of corticosteroids may be prescribed.
Patients with MCTD should consult a rheumatologist, as he or she has the expertise to treat the condition. A rheumatologist is an integral member of an MCTD treatment team and should conduct regular evaluations of the patient.
Other medical therapies include cyclophosphamide, which can be used to control interstitial lung disease. Antimalarials and calcium channel blockers can also be prescribed to help control the condition.
People who have MCTD are advised to follow a healthy diet and exercise regularly to prevent complications from the condition. They should also seek the counsel of a chronic illness support group.
People who have moderate or severe MCTD usually require low doses of corticosteroids and nonsteroidal anti-inflammatory drugs. For people with severe MCTD, more aggressive treatment may be necessary.
MCTD is a rare condition. It can have life-threatening complications if left untreated. There are no randomized controlled trials for the treatment of mixed connective tissue disease.
Because of the unpredictable nature of MCTD, it is important to consult with a physician to diagnose and treat the disorder.
Epigenome-wide association study
An Epigenome-wide association study (EWAS) was conducted to evaluate the relationship between IFN-A gene variants and mixed connective tissue disease (MCTD). This rare complex autoimmune disease shares many of the clinical characteristics of other rheumatic diseases, including pulmonary hypertension, vasculitis, and anti-U1 ribonucleoprotein autoantibodies. In addition, the MCTD-Activity Index, developed at the Institute of Arthritis and Rheumatism, enables the estimation of patient stratification and estimates of the damage associated with the disease.
Using the EWAS method, Carnero-Montoro and colleagues found that MCTD patients have an interferon-related epigenetic signature. They also observed methylation changes associated with treatment.
Genetic variants in the IFN-A, IFN-B, and IFN-G genes were associated with MCTD risk. These variants were genotyped using TaqMan allelic discrimination assays.
The study also included a training cohort of 164 COVID-19-infected individuals. They were analyzed for IFN-a/-b/g serum levels, meQTL, and microRNA analyses.
Several epigenetic markers are involved in the inflammatory process, including DNA methylation, histone modifications, transcription factors, and external factors such as bone marrow and social exposures. MeQTL, for example, is an epigenetic marker involved in the regulation of gene expression.
IFN-G gene variants were associated with the presence of anti-DNA, anti-U1-A, and rheumatoid factor. The genetic variant at position rs2069718 G/A was also associated with erosive arthritis.
DNA methylation was measured in both healthy and MCTD patients. The results indicate that a positive correlation between IFN-G rs1861493 A/G genotype and MCTD phenotype is evident. Moreover, the rs1861493 variant is associated with rheumatoid factor, while the rs2069718 A/G genotype is associated with the presence of anti-Ro60 and anti-DNA.
The effect sizes of DNA methylation are typically small, with the typical effect size not greater than 10% in terms of mean difference in the proportion of methylated DNA strands. Some studies have indicated that effect sizes can be as low as 1%, whereas others have demonstrated effects of 5% or more. However, it is important to note that the DNA sequence is mostly static. Thus, it may be possible that the results of the DNA methylation EWAS can be improved by correction for false discovery rate.
https://rarediseases.org/rare-diseases/mixed-connective-tissue-disease-mctd/