President Donald Trump once again touted hydroxychloroquine as a treatment for COVID-19, the disease caused by the new coronavirus. This time, the president falsely claimed that “people with lupus” who take hydroxychloroquine “aren’t catching this horrible virus.”

While it’s too early to say whether or not hydroxychloroquine has any protective effects, it’s not true that no lupus patients have developed the disease. In fact, the COVID-19 Global Rheumatology Alliance’s registry of COVID-19 patients with rheumatologic disease had 110 validated patients, as of April 2, and 17% of them have lupus.

“We can say that this drug is likely not 100% effective in preventing or treating COVID, and that SLE [systemic lupus erythematosus] patients should not let their guard down,” Dr. Jean Liew, administrative lead for the alliance, told us in an email.

Trump made his remarks at a coronavirus press briefing on April 4. The president has said he is a “big fan” of using hydroxychloroquine as a COVID-19 treatment — even though, as we have reported, there is limited evidence yet that it works.

Trump, April 4: We’re just hearing really positive stories, and we’re continuing to collect the data. But I’ll just speak for myself: It’s been out for a long time. It’s a malaria drug. It’s also a drug for lupus. And there’s a — there’s a study out that people with lupus aren’t catching this horrible virus. They’re not — they’re not affected so much by it. Now, maybe that’s correct; maybe it’s false. You’re going to have to check it out.

We did check it out.

The White House did not offer any support for the president’s claim that “people with lupus aren’t catching” the coronavirus. However, there is evidence from the COVID-19 Global Rheumatology Alliance that he is wrong.

The international alliance was formed to “help guide rheumatology clinicians in assessing and treating patients with rheumatologic disease.” The alliance — which is supported by the Lupus Foundation of America, Lupus Research Alliance and the American College of Rheumatology — has called on clinicians to report “all cases of COVID-19 in rheumatology patients, including those with mild or no symptoms.”

As of April 2, the group had information on 110 validated patients: 36% with rheumatoid arthritis, 17% with psoriatic arthritis and 17% with systemic lupus erythematosus, or lupus, an autoimmune disease.

“One frequently asked question: over 25% of patients who developed a COVID-19 were on HCQ at the time of diagnosis,” the group said in a tweet thread on April 2, referring to hydroxychloroquine.

“Based on early data currently available in our registry, we are not able to report any evidence of a protective effect from hydroxychloroquine against COVID-19,” the group said in an April 4 tweet. To be clear, that doesn’t mean there isn’t one — but there aren’t signs so far, and ultimately, the question will have to be answered in a randomized controlled trial.

Although the data does show that lupus patients get COVID-19, Liew cautioned us that “there are many caveats to making further inference from registry data,” especially since “this is a voluntary registry and will not capture all patients living with rheumatic disease, such as lupus, who test positive for COVID-19.”

Liew also said that Trump may have been referring to an unpublished study out of China on the effects of hydroxychloroquine in COVID-19 patients.

That study, which was posted to medRxiv on March 30, said: “Interestingly, through a follow-up survey, we found that none of our 80 SLE patients who took long-term oral HCQ had been confirmed to have SARS-CoV-2 infection or appeared to have related symptoms.” SARS-CoV-2 is the official name of the virus that causes COVID-19.

“The authors do not provide details about the survey, such as whether there was a larger number of lupus patients surveyed (the denominator), out of which 80 were able to respond and say they did not have COVID-19,” Liew pointed out. “We cannot draw any causal conclusions from those data, either.”

In the April 4 press briefing, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, was asked “what you’re seeing as far as lupus patients, in regards to coronavirus.” Fauci said, “We don’t have any definitive information to be able to make any comment that that — it’s an obvious good question, because it might be a way for us to get some interesting and potentially important data as to the role of those medications. But that’s something that is now being looked at, but we don’t have any data to be able to say anything definitively.”

That has been a consistent message from the experts: It’s still unknown whether hydroxychloroquine is a safe and effective treatment for COVID-19. More study is needed.

Several clinical trials are planned in the U.S. to test hydroxychloroquine’s ability to treat or prevent SARS-CoV-2 infection. One such study — a multi-site clinical trial that is being led by the University of Washington School of Medicine — will seek to determine whether hydroxychloroquine can prevent SARS-CoV-2 infection. The results won’t be known until, at best, this summer.

Until more is known, the Lupus Foundation of America urges lupus patients — and there are about 1.5 million Americans with the disease — to protect themselves as best they can from the highly transmissible coronavirus.

On the day that Trump made his false claim about lupus patients, the Lupus Foundation of America put out a statement that said, “There is no evidence that taking hydroxychloroquine (Plaquenil) is effective in preventing a person from contracting the coronavirus (COVID-19). People with lupus should follow the guidance of their doctor and the safety guidelines being issued by the CDC.”