Hemoglobin Electrophoresis in This Clinical Context
Hemoglobin electrophoresis is indicated in this patient to evaluate for underlying hemoglobinopathies, particularly sickle cell trait or disease, which can predispose to serious complications like splenic infarction during infectious mononucleosis.
Rationale for Testing
The combination of infectious mononucleosis and splenomegaly in a young adult creates a specific clinical scenario where hemoglobin electrophoresis becomes diagnostically important:
Splenic infarction risk: Recent case reports demonstrate that patients with sickle cell trait can develop splenic infarction during EBV infection 1. In one documented case, a 20-year-old male with SCT and mononucleosis presented with splenic infarcts, initially attributed to sickling crisis but ultimately triggered by EBV infection 1.
Overlapping pathophysiology: The splenomegaly from infectious mononucleosis combined with undiagnosed hemoglobinopathy creates a perfect storm for vaso-occlusive complications. The infection may trigger sickling in previously asymptomatic carriers 1.
When to Order
Obtain hemoglobin electrophoresis if any of the following are present:
- Left upper quadrant pain suggesting splenic complications
- Unexplained anemia beyond typical EBV-related changes
- African, Mediterranean, Middle Eastern, or South Asian ancestry (higher hemoglobinopathy prevalence)
- Family history of sickle cell disease or trait
- Any signs of hemolysis (elevated LDH, low haptoglobin, reticulocytosis)
Additional Hemolytic Workup Considerations
While evaluating for hemoglobinopathies, be aware that infectious mononucleosis itself can cause hemolytic anemia through multiple mechanisms:
- Autoimmune hemolysis: EBV can trigger warm autoimmune hemolytic anemia with positive direct antiglobulin test 2
- Antibody-mediated hemolysis: Rare antibodies against red cell enzymes (e.g., triosephosphate isomerase) or anti-i antibodies can develop 3
- Unmasking hereditary spherocytosis: The hemolytic stress of mononucleosis may reveal previously undiagnosed spherocytosis 4
Practical Testing Algorithm
- Baseline CBC with peripheral smear - look for atypical lymphocytes (confirms EBV), sickle cells, spherocytes, or signs of hemolysis
- Hemoglobin electrophoresis - identifies sickle cell trait/disease, thalassemias
- If hemolysis present: reticulocyte count, LDH, haptoglobin, direct antiglobulin test
- Imaging if abdominal pain: CT abdomen to evaluate for splenic infarction or rupture risk
Critical Pitfall
Do not dismiss abdominal pain as simple splenomegaly from mononucleosis alone. New-onset left upper quadrant pain warrants imaging to exclude splenic infarction, particularly if hemoglobin electrophoresis reveals sickle cell trait 1, 5. Splenic infarction in EBV infection, while rare, requires conservative management with possible anticoagulation and close monitoring for rupture risk 5.