Drs. Lichauco and Sinha are Fellows in Rheumatology, Department of Medicine, Montefiore Medical Center and the Albert Einstein College of Medicine, New York. Drs. Lichauco, Sinha and Barland report no commercial conflicts of interest.


>A young woman is brought to the hospital with a frightening array of problems, any one of which could be fatal. Her kidneys and heart are barely functioning. She is having difficulty breathing and her skin is covered with purplish blotches. On top of all this, she seems mentally confused and may have had a stroke.

At first, the doctors are stumped. Fearing some kind of virulent infection or poisoning, which might have caused these symptoms, they give the young woman antibiotics and dialysis treatment to aid her failing kidneys. Unfortunately, in this woman's case, the cause was neither infection nor poisoning but, instead, a rare and mysterious illness called CAPS, catastrophic antiphospholipid antibody syndrome.

What Is It?
CAPS causes the blood's clotting mechanism to go haywire, blocking blood flow to organs throughout the body. Antibiotics and dialysis will do little good. Unless the patient's doctors realize that they are dealing with CAPS, the young woman will probably not receive the high doses of immunosuppressive and anticoagulant drugs she needs.

The best feature of CAPS is that is exceedingly rare. Though still a mystery, CAPS seems to be a more dangerous cousin of a condition called antiphospholipid syndrome or APLS. Like CAPS, APLS causes over-coagulation of the blood, that is too much clotting, which leads to arterial blockages, blood platelet production problems, and, in pregnant women, spontaneous abortion.

We don't know what causes APLS or CAPS. One clue suggests that both diseases may involve an underlying immune disorder because APLS usually occurs in people who also have SLE (lupus). But even this relationship is not definite since APLS also occurs in people without lupus or other connective tissue disease. And we have seen, too, that CAPS can attack people with no previous diagnosis of APLS or of SLE.

Like many autoimmune disorders, where the body makes antibodies against itself, CAPS is more common in females, by approximately 2:1. The typical victim is a young adult, although it can affect people of any age. In about one-fifth of those who come down with CAPS, there is a triggering factor -- some illness or event that seems somehow associated with the beginning of the disease. The most common triggering factors are infections, drugs (especially anticoagulants), minor surgical procedures and hysterectomy. Late term pregnancy may also be a trigger.

How and Where CAPS Affects the Body
Kidney
The kidney is the most common target. CAPS sufferers often arrive at the hospital with serious kidney symptoms such as low or non-existent urine production and high blood pressure. These are caused by a cutoff of blood flow to the kidneys.

Brain
CAPS often causes significant deterioration in brain function, ranging from confusion to coma. Some victims experience seizures or even blindness. Unexplained changes in behavior and emotional instability are common. Like the kidney problems, these symptoms are caused by a sudden cutoff of blood flow to parts of the brain.

Respiratory system
Approximately 25% of reported cases of CAPS involve labored breathing and a nonproductive cough. The symptoms are similar to those of adult respiratory distress syndrome (ARDS).

Cardiovascular system
People with CAPS may develop acute left ventricular failure (the heart can't pump blood efficiently), caused by blockages in the smaller arteries around the heart, as well as accelerated hypertension and cerebral hemorrhaging.

Other
Other organ systems may be involved in a minority of CAPS patients. These less common CAPS effects include:
  • Adrenal and pituitary gland failure, leading to abnormally low blood pressure and electrolyte disturbances
  • Bone marrow damage, causing anemia, fluctuating blood platelet production and other problems
  • Gangrene of a hand, a foot or all of the extremities, as well as prominent and widespread dark bluish or purple patches on the skin
  • Liver problems
  • Severe abdominal cramping and pain


CAPS also sometimes occurs together with the HELLP syndrome (Hemolysis, Elevated Liver enzymes and Low Platelets), a disorder that can affect women in the last trimester of pregnancy.

Other Diseases That Can Be Mistaken For CAPS
Because fever is a common symptoms of CAPS, before beginning treatment doctors must eliminate the possibility that what appears to be CAPS may actually be a condition called disseminated intravascular coagulation (DIC), which can be caused by an overwhelming infection (sepsis). Thrombotic thrombocytopenic purpura (TTP) is another illness that can mimic CAPS. Finally, CAPS-like symptoms may also be a result of the kind of extensive damage to blood vessels caused by SLE. Fortunately, reliable tests do exist that enable doctors to identify CAPS.

Treatment
There is no well-established, standard treatment for this recently-identified and poorly-understood disease. The limited research data indicate that the best approach is a combination of immunosuppressive and anticoagulation drugs, steroids, and plasmapheresis. Plasmapheris is a procedure that lowers the amount of plasma in the blood by removing whole blood, centrifuging it to separate the plasma from other blood components and then replacing the plasma with a saline (salt) solution, fresh frozen plasma or another liquid and then returning the solution to the patient.

We think this procedure helps CAPS sufferers because it removes the antiphospholipid antibodies that cause the blood to over-coagulate in the first place.

Conclusion
Catastrophic antiphosopholipid syndrome is an uncommon and potentially fatal condition. Its rarity, plus the fact that victims must be treated aggressively and as quickly as possible, requires a high degree of knowledge and vigilance by doctors and other medical professionals. The good news is that, when treated properly and in time, many victims of CAPS recover completely.