Overview
In autoimmune hemolytic anemia (AIHA) auto-antibodies directed against red blood cells (RBCs) lead to increased RBC clearance (hemolysis). This can result in a potentially life-threatening anemia. AIHA is a rare disease with an incidence of 1-3 per 100,000 individuals. An unsolved difficulty in diagnosis of AIHA is the laboratory test accuracy. The current 'golden standard' for AIHA is the direct antiglobulin test (DAT). The DAT detects autoantibody- and/or complement-opsonized RBCs. The DAT has insufficient test characteristics since it remains falsely negative in approximate 5-10% of patients with AIHA, whereas a falsely positive DAT can be found in 8% of hospitalized individuals. Also apparently healthy blood donors can have a positive DAT. The consequences of DAT positivity are not well known and may point to early, asymptomatic disease, or to another disease associated with formation of RBC autoantibodies, such as a malignancy or (systemic) autoimmune disease. Currently, there are no guidelines to follow-up DAT positive donors.
A second unsolved difficulty is the choice of treatment in AIHA. Hemolysis can be stopped or at least attenuated with corticosteroids, aiming to inhibit autoantibody production and/or RBC destruction. Many patients do not respond adequately to corticosteroid treatment or develop severe side effects.
Currently, it is advised to avoid RBC transfusions since these may lead to aggravation of hemolysis and RBC alloantibody formation. But in case symptomatic anemia occurs, RBC transfusions need to be given. An evidence-based transfusion strategy for AIHA patients is needed to warrant safe transfusion in this complex patient group.
To design optimal diagnostic testing and (supportive) treatment algorithms, the investigators will study a group well-characterized patients with AIHA and blood donors without AIHA, via a prospective centralized clinical data collection and evaluation of new laboratory tests. With this data the knowledge of the AIHA pathophysiology and to evaluate diagnostic testing in correlation with clinical features and treatment outcome can be improved.
Eligibility
Inclusion Criteria:
- Sufficient comprehension of the Dutch language
- Signed informed consent by patient and/or parent/caretaker or donor
- Patients older than 3 months
- Patients with a positive DAT, a positive eluate and signs of hemolysis*
- Patients with a positive DAT with complement only, negative eluate, but with signs of hemolysis
- Donors with a (repeatedly) positive DAT and a positive eluate and/or clinically relevant cold auto-antibodies
Exclusion Criteria:
- Prior inclusion in the DRAIHA study