Rare disease day: PCD looks like cystic fibrosis, but isn’t

Today, on Rare Disease Day, we’re focusing on a lung condition that can be just as deadly as cystic fibrosis, is almost as common, and looks just like it – but is not CF. Most people have never heard of primary ciliary dyskinesia (PCD), although an estimated 25,000 Americans have it, and less than 1000 know it.

The San Francisco parents of 10-year-old Isabella and 8-year-old Nicholas Pennell are fortunate that their children have been diagnosed with the genetic condition known as PCD, as that means the children can receive treatment at Lucile Packard Children’s Hospital Stanford, one of the nation’s few PCD excellence centers. But getting to a correct diagnosis was a real mystery.

PCD is easy to confuse with cystic fibrosis because the two genetic diseases have similar effects on the lungs. In both disorders, mucus accumulates in patients’ lungs, causing frequent infections and severe congestion. But the roots of the two diseases are different: PCD arises from a malfunction of the cilia, the cellular “brooms” that normally sweep mucus out of the respiratory tract. CF patients, in contrast, have trouble transporting salt and water across cell membranes, causing their bodies to produce abnormally sticky mucus.

Making the matter even harder: to get an accurate diagnosis for PCD requires special equipment and biopsy analysis expertise – leading to thousands of misdiagnosed PCD patients.

Without a proper diagnosis, PCD patients can develop pneumonia and other significant pulmonary problems, and potentially die, said Carlos Milla, MD, pulmonologist for Lucile Packard Children’s Hospital Stanford and an investigator for the international Genetic Disorders of Mucociliary Clearance Consortium. Unlike CF patients, PCD patients do not necessarily need a lung transplant, and have less overall morbidity, Milla said.

“Correctly identifying PCD patients is so important,” he said.

Parents Andrew and Heidi say that Isabella and Nicholas were both hit hard with the CF-like illness at birth. The kids had constant ear and sinus infections along with serious congestion issues. Nicholas could not swallow or hold down breast milk, had pneumonia at only 3 months of age, and, by 8 months, had contracted eight ear infections.

“We spent a lot of time jumping from doctor to doctor, in late-night clinics and in the emergency room,” Heidi said. “None of the doctors we saw knew what was wrong with our children.”

After Nicholas’ second sinus surgery at age 2 in 2010, an ear, nose and throat doctor at a Bay Area hospital thought Nicholas might have PCD. Tests confirmed the rare diagnosis. Andrew and Heidi then had sister Isabella tested. Now, they had two kids with PCD.

The family was immediately referred to Milla and his team, who use aggressive treatments that include antibiotics, chest percussion to loosen mucus, and nebulized medications. As a lead international researcher for PCD, Milla is always on the hunt for new therapies to treat the disease.

“We feel confident that the long-term outlook for our children’s health is better than it would otherwise be,” Heidi said. Lung transplants are not on the horizon for Isabella and Nicholas for now, leaving them free to play their favorite sports, which include swimming and soccer.

Milla said that, despite occasional hospitalizations, the kids’ lungs are overall “doing well.” He is glad to get the word out that children with this puzzling, CF-like condition can be successfully treated. “At Stanford, we can provide expertise in PCD with both clinical and research, and you need a team of both in order to effectively treat kids with PCD,” he said.