TAMPA — Diagnosed with lung disease and determined to shed her oxygen tank, Tammy Rivero resorted to an unorthodox treatment.In 2014, Rivero took out a home equity loan to pay $7,500 and traveled from her western North Carolina home to Florida to undergo stem-cell therapy at the Lung Institute in Tampa. The institute claimed she would see results in a matter of weeks, according to a lawsuit Rivero filed last week.Instead, according to the suit, she got worse. Now Rivero, 58, is the first of what her attorney says are dozens of former patients seeking class-action status in a legal action against the institute.Rivero's suit says the Lung Institute violated Florida's Deceptive and Unfair Trade Practices Act by duping clients into believing stem-cell therapy worked despite the absence of credible medical evidence."It's one thing for folks that have an incurable disease to try experimental treatments," said Rivero's attorney, Ben Vinson Jr. of Tampa. "But it's another when the person offering the treatment knows it doesn't work."Speaking for the institute, Lynne Flaherty Margnelli, executive vice president of Regenerative Medicine Solutions, said in a statement to the Tampa Bay Times: "Lung Institute prides itself on putting patient care first and always operates with the patients' best interests in mind. We do not believe the case has any merit and we look forward to resolving this matter."A 2015 Times story said there is little evidence that the institute's treatment works for patients with incurable lung conditions such as chronic obstructive pulmonary disease, or COPD.Dr. Burton Feinerman, who was medical director at the Lung Institute when the Times story ran, said then that the American medical establishment is too slow to embrace developments."The U.S. is so far behind the rest of the world, it's pathetic," said Feinerman, who has since retired. "Doctors are not scientists. They know how to read a cookbook, but God forbid if you want to add a new recipe."Stem cells can reproduce themselves to repair tissues and mature into cells that perform a specific function, such as in the skin, muscle or blood. As part of the institute's treatment, adult stem cells are harvested from individual patients and later reintroduced into the body with the promise to restore deteriorating tissue, such as lung tissue scarred by COPD.According to the suit, the cost of the procedures ranged from $5,000 to $12,000. The suit claims the institute, which occupies a fourth floor of a downtown Tampa office building, brings in at least $2 million a month.Each patient is responsible for paying the full cost of the procedure because the institute does not accept health insurance, Medicare or Medicaid. The suit claims the institute urged prospective patients who could not afford the cost of the procedure to raise the funds through bake sales and Kickstarter campaigns.Vinson said Rivero was not told that she would have to pay for followup treatments, which she could not afford.Contact Tony Marrero at [email protected] or (813) 226-3374. Follow @tmarrerotimes.