Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disease where blood cells break apart and cause the contents to circulate freely within the bloodstream. This condition is caused by a deficiency in a gene called the phosphatidylinositol glycan anchor biosynthesis class A (PIGA). This deficiency causes some blood cells to become more vulnerable. When these vulnerable blood cells replicate, PNH occurs. Notably, this gene difference is not inherited. It simply occurs spontaneously.

Symptoms

Symptoms of PNH vary dramatically across patients. Some have mild symptoms while some experience severe symptoms. The more severe symptoms can include kidney disease, blood clots, hemoglobin within the urine, bone marrow dysfunction, and hemolytic anemia.

Hemolytic anemia is a condition where the body can’t make red blood cells fast enough to make up for the ones the body is losing. Symptoms of this condition include headaches, fatigue, breathing issues, chest pain, and a rapid heart rate. When hemolytic anemia progresses it may lead to abdominal contractions, severe fatigue, esophageal spasms, difficulty swallowing, and erectile dysfunction.

Of course, many of these symptoms can also be related to other conditions. This means PNH patients often take far too long to be diagnosed, and therefore far too long to be treated.

Treatment

The primary medications used as treatments for this condition are ravulizumab and eculizumab. These medications prevent the body from breaking down red blood cells. Ravulizumab must be taken once every 8 weeks while eculizumab requires a dose every 2 weeks.

Other supplemental therapies include folic acid supplements, iron supplements, steroids, immunosuppressive therapies, anti-coagulation therapies, growth factors, and blood transfusions.

Patients with severe PNH may require a bone marrow transplant.

Diagnosis

Typically, PNH patients are diagnosed with a blood cell analysis. However, genetic testing can also be helpful to assess differences in PIGA.

PIGA deficiency effects many cells but it starts within one blood stem cell. As this cell multiplies, the blood cells turn into PNH cells. The stem cell essentially makes copies of itself, which then turn into PNH red blood cells.

However, PIGA alone doesn’t lead to PNH. Also required is the process for cells to expand and multiply. Researchers are still working to figure out why this multiplication occurs in some patients but not in others.

You can read more about this condition and the latest in research here.