Quick answer
In severe COVID-19 with lung damage, trials of umbilical cord stem cells found better one-month survival (91% vs 42% in a 24-patient study) and more complete healing of lung lesions: at one year, 17.9% of treated patients had a normal CT scan, versus none on placebo. Small exosome studies reported better oxygenation. In pulmonary fibrosis and COPD there are only small studies, with gains in lung capacity, symptoms and flare-ups. None of these therapies is approved for lung disease, and other trials were negative.
Why it matters
Lung diseases such as COVID-19 lung damage, pulmonary fibrosis and COPD can limit breathing, energy and daily life. Mesenchymal stem cells and their exosomes are being studied because they can calm inflammation and support tissue repair. These are the human clinical studies that found improvement, with their actual numbers.
Severe COVID-19: survival and lung healing
This is the area with the most studies and the best results.
| Study | Patients | Main finding |
|---|---|---|
| Lanzoni, 2021 (randomized, double-blind) | 24 with respiratory distress | One-month survival 91% vs 42% |
| Shi, 2021 (placebo-controlled) | 100 with lung damage | Fewer solid lung lesions at day 28 |
| Shi, 2022 (one-year follow-up) | 100 | 17.9% with a normal CT vs 0% on placebo |
| Qin, 2024 (meta-analysis) | 1,019 in 17 trials | 24% lower 28-day mortality |
Exosomes: better oxygenation in small studies
Exosomes are tiny vesicles released by stem cells that carry repair signals. After one intravenous dose in 24 patients with severe COVID-19, 71% recovered and oxygenation improved by 192% on average. In another study, 7 patients inhaled nebulized exosomes for five days; they tolerated them well and all showed some improvement of lung lesions on CT. These studies are small and had no comparison group.
Pulmonary fibrosis and COPD: early signals
- Idiopathic pulmonary fibrosis: in a 20-patient placebo-controlled trial, forced vital capacity rose 7.8% in a year with high-dose stem cells, while it fell 5.9% on placebo.
- COPD: in a 20-patient pilot study, one infusion of umbilical cord stem cells was followed by less shortness of breath, better quality of life and fewer flare-ups over six months, although lung function did not change significantly.
What it means for you
- The strongest evidence is in severe COVID-19; in pulmonary fibrosis and COPD it is promising but preliminary.
- There are also negative trials, listed under the limitations and references below.
- These therapies are studied as a complement to your pulmonologist's treatment, who remains your main doctor.
If you live with a lung condition, Longevity Clinic's physicians in Veracruz can review your records and the evidence for your case in a free consultation before you decide anything, and give you a written summary to share with your doctor at home. More summaries are available in Spanish.
Studies cited
Lanzoni G, et al. Stem Cells Translational Medicine
Umbilical cord mesenchymal stem cells for COVID-19 acute respiratory distress syndrome: A double-blind, phase 1/2a, randomized controlled trial
Reported result: 31-day survival was 91% with umbilical cord stem cells versus 42% in the control group. Treated patients recovered faster and had lower inflammatory markers on day 6. There were no serious adverse events related to the infusions.
Shi L, et al. Signal Transduction and Targeted Therapy
Effect of human umbilical cord-derived mesenchymal stem cells on lung damage in severe COVID-19 patients: a randomized, double-blind, placebo-controlled phase 2 trial
Reported result: At day 28, stem cells reduced the proportion of solid lung lesions by 15.45% more than placebo. The reduction in total lesion volume (13.31%) and the longer 6-minute walk (27 m) favored stem cells but did not reach statistical significance. Adverse events were similar in both groups.
Shi L, et al. EBioMedicine
Human mesenchymal stem cells treatment for severe COVID-19: 1-year follow-up results of a randomized, double-blind, placebo-controlled trial
Reported result: At one year, 17.9% of stem cell patients (10 of 56) had a normal lung CT scan, versus none in the placebo group. Treated patients reported fewer symptoms at every visit, with no difference in adverse events or tumor markers.
Qin J, et al. Stem Cell Reviews and Reports
Mesenchymal Stem Cells on Mortality in COVID-19 Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Reported result: Mesenchymal stem cells lowered 28-day mortality (relative risk 0.76; 95% CI 0.62–0.93). At 60 and 90 days the difference was no longer significant.
Sengupta V, et al. Stem Cells and Development
Exosomes Derived from Bone Marrow Mesenchymal Stem Cells as Treatment for Severe COVID-19
Reported result: After a single intravenous dose of exosomes, 71% of patients recovered and oxygenation (PaO2/FiO2) improved by 192% on average. C-reactive protein fell 77% and lymphocyte counts rose. No adverse events were seen within 72 hours.
Zhu YG, et al. Stem Cell Research & Therapy
Nebulized exosomes derived from allogenic adipose tissue mesenchymal stromal cells in patients with severe COVID-19: a pilot study
Reported result: Five days of nebulized (inhaled) exosomes were well tolerated, with no adverse events. Every patient showed some resolution of lung lesions on CT, most clearly in 4 of 7, within the first 7 days.
Averyanov A, et al. Stem Cells Translational Medicine
First-in-human high-cumulative-dose stem cell therapy in idiopathic pulmonary fibrosis with rapid lung function decline
Reported result: At 12 months, forced vital capacity rose 7.8% with high-dose stem cells, while it fell 5.9% with placebo. The 6-minute walk and oxygen diffusion also improved. There was no difference in mortality or in fibrosis measured by CT.
Le Thi Bich P, et al. Stem Cell Research & Therapy
Allogeneic umbilical cord-derived mesenchymal stem cell transplantation for treating chronic obstructive pulmonary disease: a pilot clinical study
Reported result: After one infusion of umbilical cord stem cells, patients had less shortness of breath (mMRC scale), better quality-of-life scores (CAT) and fewer flare-ups over 6 months. Lung function (FEV1) and the 6-minute walk did not improve significantly.
Frequently asked questions
Can stem cells help with lung damage after COVID-19?
It is the area with the best results. In a placebo-controlled trial, patients with severe COVID-19 treated with umbilical cord stem cells had more complete healing of lung lesions, and at one year 17.9% had a normal CT scan versus none on placebo. Even so, other trials were negative and it is not an approved treatment. Pulmonary rehabilitation remains the foundation of recovery.
Do stem cells or exosomes work for COPD or pulmonary fibrosis?
There are promising but very early signals. In pulmonary fibrosis, a 20-patient trial found lung capacity increased with high-dose stem cells. In COPD, a 20-patient pilot study showed less shortness of breath and fewer flare-ups, although an earlier placebo-controlled trial did not improve lung function. Larger studies are needed.
Should I stop my lung medications if I receive a regenerative therapy?
No. In every study the therapies were added to standard care. Inhalers, antifibrotic drugs, oxygen, pulmonary rehabilitation and vaccines prescribed by your pulmonologist are not replaced. Any complementary option is assessed together with your treating doctor.
Sources
- Bowdish ME, et al. A Randomized Trial of Mesenchymal Stromal Cells for Moderate to Severe Acute Respiratory Distress Syndrome from COVID-19. Am J Respir Crit Care Med, 2023. (Stopped for lack of efficacy, 222 patients)
- Lightner AL, et al. Bone Marrow Mesenchymal Stem Cell-Derived Extracellular Vesicle Infusion for the Treatment of Respiratory Failure From COVID-19: A Randomized, Placebo-Controlled Dosing Clinical Trial. Chest, 2023.
- Weiss DJ, et al. A placebo-controlled, randomized trial of mesenchymal stem cells in COPD. Chest, 2013. (62 patients, no improvement in lung function)