The formation of excess fibrous connective tissue between the cells of various organs or tissues as a reactive process is called fibrosis. It can cause stiffening or hardening of tissues in skin, internal organs and joints. It can be reactive, pathological or in a benign state. When fibrosis arises from a single tissue, it is called Fibroma and in response to an injury it is called scarring.
Fibrosis may occur in many tissues within the body due to damage or inflammation, examples include:
- Pulmonary Fibrosis, affecting the lung
- Cystic Fibrosis affecting the mucus glands
- Heart Fibrosis, affects the heart that is damaged post myocardial infarction
- Liver Cirrhosis, accumulation of tough, fibrous scar tissue in the liver
- Bone marrow Fibrosis, affects the bone marrow and prevents normal production of blood cells
- Mediastinal Fibrosis, blocks respiratory channels and blood vessels due to calcified fibrosis of the lymph nodes
- Skin fibrosis, due to the formation of scar tissues due to injury.
During the early stages of Lymphedema, tissues swell with protein-rich lymph that may not drain properly. The tissues are soft to touch; this condition is known as pitting edema. There is pressure on these tissues pushing the fluid aside thus leaving an indentation. If left untreated at this stage, the lymph may become fibrotic thus forming fibrosis. As fibrosis develops, the normal tissues are replaced by the scar-like structures that cause hindrance to lymph drainage. Fibrosis can occur in slightly swollen tissues too. As the lymph cannot drain properly, it leads to accumulation of protein molecules in the tissues thus increasing formation.
- It may be caused by a disease or while treating the disease.
- Other causes could include burns, injuries, chemotherapy, radiation and gene mutation.
- It is also possible that the causes may remain idiopathic, i.e. the cause is unknown.
Effects of fibrosis
Symptoms of fibrosis can vary depending on the location and severity of the condition. Common symptoms include scarring.
- Fibrosis will harden the affected tissue, at times they also swell. These changes can make the tissues incapable of functioning properly; the fluid flow through these affected tissues might be reduced. When present in the lungs, the lung is unable to expand adequately leading to shortness of breath.
- Fibrosis of joints can cause pain and stiffness of the affected joint.
- Fibrosis in the shoulder may lead to frozen shoulder.
- Fibrosis of the tendons may lead to deformity of fingers and hand.
Progressive Massive Fibrosis
Progressive massive fibrosis is a lung disease that is predominantly reported in people who work in mines. Hence it is also called Coal worker's Pneumoconiosis. Fibrosis is a nodular formation in different regions of the body. Often lungs are the most vulnerable. This is because of aerosol initiation, which has a faster chance of nodule formation causing tissue damage.
Most conditions associated with massive fibrosis are coherent to silicosis and pneumoconiosis. Lesions are caused due to tissue necrosis, which leads to hardening of the tissue forming nodular structures. In case of progressive fibrosis, massive scars are noticed because of dense agglomeration of the thickened nodules. These nodules predominantly appear in the upper lobes causing respiratory difficulties.
The onset of this disease is triggered by macrophage proliferation in the respective regions. The macrophages engulf the inhaled silicon particles causing the production of interleukin -I which facilitates the chemical mediation for tissue necrosis. Silica is commonly found in these necrotic nodules. The adverse effects of these silica particles are the onset of Pulmonary Alveolar Proteinosis (PAP) causing the accumulation of large particles, which can be noticed as spaces on radiological examination. Along with the affected upper lobe, the interstitial zones of the lower lobe are also obstructed and bronchial regions are damaged with the infiltration of the nodules. Honeycomb lung or asbestos bodies are common references for progressive massive fibrosis as both these conditions have giant cells upon pathological examination. Bronchogenic carcinoma and mesothelioma are the associated adverse conditions of progressive massive fibrosis.
The evaluation of patients suffering progressive massive fibrosis includes the understanding of the type of chemical or particle inhaled as it enables the physicians to rule out diagnostic errors. In cases such as pleural plaques, calcified regions of the lungs are noticed which is another cause of asbestosis. The lower region of the lungs are predominantly affected. In case of interstitial fibrosis, the bronchus and alveoli are affected with characteristic nodules of the upper and mid region. The evaluation is based on the type of chemical and the respective interleukins it releases. Most patients associated with these conditions are miners, shipyard workers, automobile mechanics and petrochemical employees.
Diagnosis and Treatment
Most diagnostic evaluations are radiological in origin as the MRI provides detailed description about the zones of the fibrosis and the size of each nodule. Histopathological analysis studies the intensity of the necrosis, giant cell presence and the macrophagic proliferation patterns. The treatment pattern is based on symptomatic analysis. Since the condition includes both lower and upper lobes, any associated mycobacterial infection has to be treated. Oxygen is given as a critical care measure in patients with hypoxemia. Surgical interventions are applicable in case of intense and irreversible tissue necrosis. Patients with progressive massive fibrosis are advised to quit smoking if as it causes intense damage.
Cystic fibrosis is a condition where there is abnormal production of thick and sticky mucus within the lungs and digestive tract. It is a genetic disorder that affects children and young adults. The thick mucus blocks the tiny openings in the lungs thereby trapping bacteria and bringing on various infections. The mucus also clogs the pancreatic passages. This prevents release of enzymes much needed for digestion. Consequently there is poor nutrition and possible diarrhea. This condition can also affect sweat glands and male reproductive system. Cases of cystic fibrosis are noticed more prominently among those Caucasians, especially of Northern or Central European descent. Often cystic fibrosis is diagnosed at birth where the infant's gut is blocked with thick meconium. While most cases of cystic fibrosis are detected in the first 3 years, some cases may be diagnosed in early teens. Other symptoms are delayed growth and failure to gain weight normally. Persons suffering from Cystic fibrosis are more susceptible to bacterial chest infections. Coughing, wheezing and excessive production of sputum are noticeable symptoms. A person suffering from cystic fibrosis is likely to suffer from oily and smelly stools, salty skin and abdominal pain. Other symptoms of cystic fibrosis is polyps in the nose, enlarged liver and spleen and fertility problems.
The first DNA-based blood test has been approved by the U.S. FDA in March 2005. This test helps in detecting the affected gene. Other diagnostic tools include sweat chloride test, fecal fat test and study of pancreatic function. Chest physiotherapy aids in loosening sticky mucus thereby bringing relief. Daily enzyme replacements are prescribed to facilitate digestion. Lung and respiratory infections are tackled with antibiotics. Other measures such as oxygen for easier breathing, postural drainage and vitamin supplements help in improving the quality of life for the patient.