Twenty-two former Grady Memorial Hospital patients, many of them uninsured illegal immigrants, had potential life-saving dialysis treatments discontinued Thursday after a contract between the hospital and a national dialysis provider expired.Most of the patients, because they are in the country illegally, don’t qualify for Medicare, which covers dialysis for most Americans with end-stage renal disease. Without regular dialysis, experts say, people suffering from the disease can die within weeks. The emergency room is now the immigrants’ only option, said Dorothy Leone-Glasser, president of the nonprofit Advocates for Responsible Care. “These patients are left in a very dangerous situation,” she said....