Almost everyone knows someone living with a serious chronic condition like diabetes or high blood pressure, and knows how those illnesses can have a major effect on daily life. However, few people have heard of cold agglutinin disease (CAD), a rare and severe, autoimmune condition where the body attacks and destroys its own red blood cells. Yet for the estimated 12,000 patients in the US, Europe, and Japan living with the disease – and more in other parts of the world – the disease is completely life-changing.
“I've gone from being very active on a regular basis to some days when I can barely walk to my own car without losing my breath,” said Jodi, who has been diagnosed with CAD. “This impacts everything about my life.”
In fact, cold agglutinin disease is far more serious than previously thought. Results from separate retrospective studies conducted in the US and Japan showed that people with CAD have an increased risk of thromboembolic events, which are blood clots that can include heart attack and pulmonary embolism (US study, TE rate 31% in CAD patients vs 20% in control patients, p-value <0.0001; Japan study, 35% vs 18% respectively, p-value <0.0001). What’s more, the Danish study analyzed patient registry data for 72 people with CAD and found that people with CAD are twice as likely to die in the first five years after diagnosis when compared to the general population (n=720). Additional studies are needed to continue to understand the mortality risks of CAD.
“These data show that greater understanding is needed about the risks associated with cold agglutinin disease, and reinforce the pressing need for approved treatment options for this life-threatening condition,” said Jaime Morales, MD, FAAP, Global Head for Complement Disorders and Hemoglobinopathies, Sanofi Genzyme. “In addition, it appears that all patients with CAD have these risks, regardless of their race or where they live.”
Red Blood Cells Become Targets for Destruction
Antibodies act as a signal to the immune system to attack the cells to which they are attached, a normal and necessary immune function of the body to fight infections, for example. In people with CAD, an individual’s body begins to generate antibodies against its own healthy red blood cells, continually destroying large numbers of them in a process called hemolysis.
This causes people with CAD to suffer from chronic anemia that saps their energy. It also creates circulatory problems, particularly in the extremities like hands and feet, that makes them hyper-sensitive to cold. That affects everything from their diet to how they manage what should be normal, daily activities like going into air-conditioned spaces and eating cold food.
The disease can be challenging to recognize and diagnose, in part because it is so rare and in part because people tend to ignore early symptoms. People with CAD are typically diagnosed in their 60s, when the incidence of anemia tends to increase, so it can be discounted as just anemia or a part of aging.
“What we learned from the Danish study is that the increased mortality associated with CAD starts as early as the first year after diagnosis,” said Morales. “This makes early diagnosis even more crucial for all people with CAD. Additional studies are needed to better understand this increased mortality risk.”
Today, there are no approved treatments for CAD.
“If there’s a treatment out there that would help with this disease and improve the quality of life, it would be a tremendous impact,” Jodi says.