J Kinney, S M c Manus, D Spriel, L Petkovic, K Leigh London Health Sciences Centre, London, ON

1. Two Case Reports of Hemolytic Anemia Due to a Low Titred, High Thermal Amplitude, Cold Reactive Autoantibody J Kinney, S McManus, D Spriel, L Petkovic, K Leigh London Health Sciences Centre, London, ON Introduction Most antibodies responsible for autoimmine hemolytic anemia (AIHA) generally fall into two serological categories. Antibodies that react optimally at 37oC are usually of the IgG type while those antibodies that react best at 4oC are of the IgM type. While the serological investigation carried out in the blood transfusion laboratory does not determine whether a patient has hemolytic anemia, the investigation does aid in determining if a patient’s hemolysis is immune mediated. The serological findings are significant because the treatment for AIHA is often based on the serological findings. We reported two cases in which the serological findings were not typical for either warm AIHA or cold agglutinin syndrome. CASE #2 CASE #1 • 79 year old female referred to Emergency department from family physician due to fatigue. Her Hb had decreased from 105 g/L to 66 g/L over a 2 month period • 36 year old male presented in the Emergency department complaining of fatigue, jaundice and dark coloured urine Laboratory Findings Laboratory Findings Direct Antiglobulin Test and Antibody Screen Cold Agglutinin Titre and Thermal Amplitude • Initial hemoglobin (Hb) 105 g/L • Total Bilirubin 111.3 umol/L • Direct Antiglobulin Test: Negative • Weak reacting antibody detected in screening cells using column agglutination with anti-IgG Additional Testing • WBC 9.0 x 109/L • Hb 66 g/L • RBC morphology: polychromasia, macrocytes, nucleated red cells, spherocytes, agglutination • Total bilirubin 78.3 umol/L • LD, serum 463 U/L • Initial DAT was 4+ and 6% albumin control 2+ • An eluate at 48oC was required before the 6% albumin control was negative (DTT treatment would be an alternative especially if anti-IgG was negative) • Differential DAT showed 2+ results with monospecific anti-IgG and monospecific anti-C3b, -C3d. • Antibody screen was 2+ with both screening cells using column agglutination 4oC 25oC 37oC • More sensitive DAT techniques including MTS Gel, and cold wash were used both with negative results • DTT treatment of serum to assess IgG reactivity was invalid due to a negative dilution control • Donath-Landsteiner test for paroxsymal cold hemoglobinuria was negative • Tests for Epstein Barr Virus and Cytomegalovirus IgM antibody were negative • Tests for hepatitis B and C were negative Adult Cells 4 1 1 Cord Cells 4 1 1 Auto Cells 4 2 1 Outcome • Patient Hb dropped to 41 g/L within 48 hours of admission • Due to patient’s worsening condition, and unknown etiology of hemolysis, the patient was started on 150 mg/day dose of prednisone • Patient was also treated with 3 rounds of plasmapheresis • Patient required a total of 12 units of packed red cells during his 10 day hospital admission • Patient was discharged from hospital with a Hb of 79 g/L and has had no reoccurrence to date Outcome • Patient was diagnosed with chronic lymphocytic leukemia with a secondary AIHA • Attempt to keep patient warm to prevent Hb from decreasing was unsuccessful • Patient Hb decreased to 55 g/L • Treatment with 75 mg/day prednisone was initiated • Patient was discharged from hospital 2 weeks after admission with a Hb 74 g/L • Patient did not require transfusion of red cells Cold Agglutinin Titre and Thermal Amplitude Discussion • IgM autoimmune hemolytic anemia has most commonly been associated with intravascular hemolysis and preferential cold reactivity1 • The two cases described are examples of IgM which showed similar reactivity over wide temperature profile. • Both patients responded to prednisone which is atypical for Cold Agglutinin Syndrome2 • Our findings are typical serology of warm AIHA associated with IgM autoantibodies as reported by Garratty et al 1,3 • Both cases represent the importance of pursuing unusual serological reactions in relation to the patient’s clinical picture • Performing cold agglutinin titres and thermal amplitude testing aid in diagnosing and treatment • IgM antibodies with a high thermal amplitude and/or high titre may react in MTS Gel anti-IgG cards often with a mixed field reaction appearance • In the primary author’s (JK) experience many laboratories would attempt to prewarm away reactions. These results may lead to incorrect diagnosis and/or treatment • Resolving the positive 6% albumin control in case #2 and more accurately assessing the presence of IgG on the patient’s red cells was helpful in determining the course of treatment for this patient 4oC 25oC 37oC Adult Cells 4 1 1 Cord Cells 2 2 2 References • Petz LD, Garratty G: Immune Hemolytic Anemias, 2nd edition. Philadelphia: Churchill Livingstone, 2004. • Dacie JV: The Haemolytic Anemias, 3rd ed. vol.3. New York: Churchill Livingstone, 1992 • Garratty G, Arndt P, Leger R: Serological findings in autoimuunue hemolytic anemia associated with IgM warm autoantibodies (abstr). Blood 2001;98:61a Auto Cells 2 1 1 • Special Acknowledgements: • Linda Thomson: Poster design