Platelet-rich plasma

Platelet-rich plasma (PRP), also known as autologous conditioned plasma, is a concentrate of platelet-rich plasma protein derived from whole blood, centrifuged to remove red blood cells. Evidence for benefit is poor as of 2016.^[1] The cost per injection is generally $US 500 to 2,000 as of 2019.^[2]

Medical use

Evidence for benefit of PRP is poor as of 2016.^[3][1] It has been investigated for chronic tendinitis,^[4] osteoarthritis,^[5] in oral surgery,^[6] and in plastic surgery.^[7]

A 2019 review found it not to be useful in rotator cuff disease.^[8] While an older review found that it may be useful.^[9] Tentative evidence supports its use in osteoarthritis (OA) of the knee.^[10][11] A 2019 meta-analysis found that PRP might be more effective in reducing pain and improving function than hyaluronic acid in knee OA.^[12]

A 2009 review found few randomized controlled trials that adequately evaluated the safety and efficacy of PRP treatments and concluded that PRP was “a promising, but not proven, treatment option for joint, tendon, ligament, and muscle injuries”.^[13] As compared to other conservative treatments for non-surgical orthopedic illnesses (e.g. steroid injection for plantar fasciitis), evidence does no support the use of PRP as a conservative treatment.^[14] A 2018 review found that evidence was lacking for Achilles tendinopathy.^[15] A 2019 meta-analysis found that, for most outcomes in Achilles tendinopathy, PRP treatment did not differ from placebo treatment.^[16]

A 2010 Cochrane review of use in sinus lifts during dental implant placement found no evidence of benefit.^[6] A 2013 review stated more evidence was needed to determine effectiveness for hair regrowth.^[17]

A 2014 Cochrane review of PRP in musculoskeletal injuries found very weak evidence for a decrease in pain in the short term, and no difference in function in the short, medium or long term. There was weak evidence that suggested that harm occurred at comparable, low rates in treated and untreated people.^[1] Similarly, another 2017 review for treating pain on skin graft donor sites found the evidence for benefit was poor.^[18]

It has not been shown to be useful for bone healing.^[19] A 2016 review of PRP use to augment bone graft found only one study reporting a difference in bone augmentation, while four studies found no difference.^[20]

Adverse effects

Adverse effects have been poorly studied. The single systematic review of the literature did not report of the types and number of adverse events.^[21] In 2019, Health Canada stated that most autologous cell therapies have little evidence showing they work and can pose risks, such as cross-contamination between people if equipment is not sterilized properly or potentially dangerous immune reactions.^[22] Health Canada stopped Canadian clinics from offering these types of services with a donor-patient model.^[23] Health Canada later clarified that PRP treatments harvested from, and given back to, the same person (in a single procedure) was not covered by its initial guidance as the procedure falls under health care provider regulatory bodies (rather than Health Canada).^[24]

Chinese doctors ‘using plasma therapy’ on COVID-19 patients

SHANGHAI: Doctors in Shanghai are using infusions of blood plasma from people who have recovered from the coronavirus to treat those still battling the infection, reporting some encouraging preliminary results, a Chinese professor said on Monday

A top emergency expert at the World Health Organization (WHO) said later that using convalescent plasma was a “very valid” approach to test, but that it was important to get the timing right to maximise the boost to a patient’s immunity.

The coronavirus epidemic is believed to have originated in a seafood market in the central city of Wuhan, capital of Hubei province, and has so far killed 1,770 peopleand infected more than 70,000 in mainland China.

China’s financial hub of Shanghai on Monday had 332 infected cases, one of whom died in recent weeks. 

Lu Hongzhou, professor and co-director of the Shanghai Public Health Clinical Centre, said that 184 cases were still hospitalised, including 166 mild cases, while 18 were in serious and critical conditions.

He said the hospital had set up a special clinic to administer plasma therapy and was selecting patients who were willing to donate. The blood would be screened to check if he or she had other diseases like hepatitis B or C, he added.

“We are positive that this method can be very effective in our patients,” he said.

There are no fully licensed treatments or vaccines against the new coronavirus, and the process of developing and testing drugs can take many months and even years.

‘VERY IMPORTANT AREA’

Convalescent plasma has been proven “effective and life-saving” against other infectious diseases, including rabies and diphtheria, Dr Mike Ryan, head of WHO’s health emergencies programme, told reporters in Geneva.

“It is a very important area to pursue,” Ryan said.

“Because what hyperimmune globulin does is it concentrates the antibodies in a recovered patient. You are essentially giving the new victim’s immune system a boost of antibodies to hopefully get them through the very difficult phase.

“So it must be given at the right time, because it mops up the virus in the system, and it just gives the new patient’s immune system a vital push at the time it needs it. But it has to be carefully timed and it’s not always successful.”

Ryan added: “So it is a very important area of discovery, and I believe they are starting trials on that in China. But it is a very valid way to explore therapeutics, especially when we don’t have vaccines and we don’t have specific antivirals.”

As well as using plasma therapies, the Chinese doctors are also trying antiviral drugs licensed for use against other infections to see if they might help.

Scientists are testing two antiviral drugs and preliminary results are due in weeks, while the head of a Wuhan hospital had said plasma infusions from recovered patients had shown some encouraging preliminary results.