From the Research
Paroxysmal cold hemoglobinuria (PCH) is a rare autoimmune hemolytic anemia characterized by the sudden destruction of red blood cells after exposure to cold temperatures, and the most recent and highest quality study suggests that it is often overlooked as a potential etiology of hemolysis and is challenging to diagnose due to complicated testing methods required 1.
Definition and Pathophysiology
PCH occurs when Donath-Landsteiner antibodies, which are specific IgG autoantibodies, bind to red blood cells in cold conditions and then activate the complement system when the blood rewarms, causing hemolysis.
- The condition can be either primary (idiopathic) or secondary to infections (particularly syphilis, viral infections like influenza, or measles) or certain hematologic malignancies.
- Patients typically experience symptoms including fever, abdominal pain, back pain, headache, vomiting, and diarrhea shortly after cold exposure.
- The hallmark sign is dark or reddish-brown urine (hemoglobinuria) due to the presence of free hemoglobin released from destroyed red blood cells.
Diagnosis and Treatment
- Diagnosis involves the Donath-Landsteiner test, which detects the characteristic biphasic antibody.
- Treatment primarily consists of avoiding cold exposure and providing supportive care including warming, hydration, and sometimes blood transfusions in severe cases.
- Immunosuppressive therapy with corticosteroids may be used, though their effectiveness is variable in PCH compared to other autoimmune hemolytic anemias, as noted in a recent study 1.
- A systematic review of all reported cases of PCH confirmed by Donath-Landsteiner testing found that the use of corticosteroids is common, although there was no significant difference in the length of hospitalization for patients with and without steroid therapy 1.
- The most effective treatment approach is to avoid cold exposure and provide supportive care, as this can help to reduce the risk of hemolysis and improve outcomes in patients with PCH 2, 1.