In a recent study published in the journal Cureus, researchers conducted a literature review to determine whether platelet-rich plasma therapy could help slow disease progression through lung regeneration in patients with chronic respiratory disease.
Chronic respiratory disease
Chronic respiratory disease comprises many disorders related to the respiratory system, such as asthma, chronic obstructive pulmonary disease (COPD), and interstitial lung fibrosis, of which COPD is the most fatal, causing close to 3.23 million deaths worldwide in 2019. Statistics suggest that approximately 37 million people in the United States live with chronic respiratory disease, and over 150,000 individuals in the country succumbed to the disease in 2020.
Chronic bronchitis and emphysema as the two prominent disorders constituting COPD, causing abnormal airflow into and out of the lungs. Emphysema causes the destruction of the alveoli, which is where the exchange of gases occurs in the lungs, while chronic bronchitis causes excessive mucus production and obstruction of airways.
While tobacco smoking is the predominant trigger for COPD, genetic causes, abnormal lung development during childhood, and occupational exposure to substances can also cause chronic bronchitis and emphysema.
One of the complications of the recent coronavirus disease 2019 (COVID-19) pandemic is the rise in acute respiratory distress syndrome (ARDS), which leads to lung scarring and fibrosis. The fluid buildup in the alveoli during ARDS causes acute lung damage.
Diagnosis and treatment
A combination of spirometry and pulmonary function tests, such as forced expiratory ventilation during the first second of expiration (FEV1) and forced vital capacity during effortful expiration (FVC), is generally used to diagnose COPD. Bronchodilators, oral and inhaled steroids, anticholinergic agents, and oxygen therapy have been used to prevent flare-ups and provide symptomatic relief, but COPD currently does not have a cure.
Current research on COPD treatment is exploring the use of mesenchymal stem cell therapy in lung regeneration. Although mesenchymal stem cells are a promising option, obtaining mesenchymal stem cells is either painful and invasive through adipose tissue and bone marrow or controversial when procured from embryonic or umbilical cord tissue.
In this respect, platelet-rich plasma provides a viable and promising alternative. Platelet-rich plasma can be obtained from blood and is essentially serum and plasma without erythrocytes but containing high concentrations of tissue-repairing growth factors such as epidermal growth factor (EGF), insulin-like growth factor (IGF), platelet-derived growth factor (PDGF), platelet-derived angiogenesis factor (PDAF), and vascular endothelial growth factor (VEGF).
While the exact mechanism through which platelet-rich plasma causes tissue regeneration is not well understood, platelets are thought to play a role in maintaining barrier integrity by enhancing endothelial growth, neutralizing barrier permeability, and inducing cell proliferation. The application of platelet-rich plasma therapy in dermatological, cosmetic, and oromaxillofacial surgeries and in treating orthopedic injuries has been favorable.
The present review aimed to evaluate existing literature for evidence on the benefits of using platelet-rich plasma to regenerate lung tissue in patients with chronic respiratory disease. The review included various types of studies on human patients as well as animal models and patients.
Two cohort studies on COPD patients reported that treatment with platelet-rich plasma improved the Clinical COPD Questionnaire (CCQ) scores, with decreased severity and symptoms and improved mental and functional health, indicating that platelet-rich plasma therapy alleviated the COPD symptoms and improved the quality of life of the patients.
Another study that evaluated the FEV1 and FVC scores in COPD patients reported improved lung function scores after treatment with platelet-rich plasma. Additionally, case studies in patients with COPD and ARDS induced by COVID-19 revealed that patients experienced improved lung function, decreased disease severity, and improvements in functional and mental health after platelet-rich plasma therapy.
Furthermore, a randomized controlled trial on platelet-rich plasma therapy for smoke inhalation patients showed a decrease in the length of intubation days and hospital stays, as well as mortality rates.
Two studies on racehorses reported the beneficial effects of platelet-rich plasma therapy in decreasing inflammation and bleeding, with one in which racehorses having inflammatory airway disease showed significant improvement after treatment with platelet-rich plasma. Other animal model studies using mice and pigs also showed improvements in cases of pulmonary lung fibrosis and anastomosis after platelet-rich plasma therapy.
A clinical trial that evaluated the efficacy and safety of platelet-rich plasma infusions in treating COVID-19-related ARDS reported a reduction in the inflammation marker C-reactive protein after treatment.
Additionally, clinical trials which evaluated the use of platelet-rich fibrin glue and platelet-rich plasma in patients suffering from chylothorax post-esophagectomy and cardiac surgery patients, respectively, reported faster recovery and healing and reduced inflammation. Furthermore, studies also reported reduced joint inflammation and synovial degeneration after platelet-rich plasma therapy.
Overall, evidence from cohort studies and clinical trials involving cases of chronic respiratory disease in both humans and animals indicated that platelet-rich plasma therapy helps in lung tissue regeneration, slowing down disease progression and improving the quality of life.