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The unintended consequences of a bowl of soup

Published:January 13, 2020DOI:https://doi.org/10.1016/j.ejim.2019.12.017

      1. Introduction/Case description

      A 33-year-old Romanian woman presented with a one day history of “cola-coloured” urine with associated fevers. She reported generalised malaise, arthralgia and reduced appetite for 24 h. The patient had a history of beta-thalassemia trait. She was not taking any regularly prescribed or over-the-counter medications and had no known allergies. Scleral icterus was noted on examination. There was no pathological lymphadenopathy or organomegaly. Her laboratory investigations were as follows; haemoglobin 3.6 g/dL, mean corpuscular volume 99.2 fl, platelets 219 × 109/L, white cell count 13.4 × 109/L, reticulocytes 351 × 109/L, direct antiglobulin test – negative, total bilirubin 88 umol/L, C-reactive protein 100 mg/L, lactate dehydrogenase 1250 u/L (upper limit 240 u/L) and haptoglobin 0.41 umol/L.

      2. Diagnosis

      The blood film (Image 1) demonstrated ghost cells, hemi-ghosts, rouleaux formation, polychromasia, bite cells and microspherocytes [
      • Veneri D.
      • et al.
      Blood smear, a key diagnostic tool in hematology: lessons from two cases of acute hemolysis in previously undiagnosed G6PD deficiency.
      ]. A Glucose-6-Phosphate Dehydrogenase (G6PD) assay revealed 1.84 units/g of haemoglobin (normal range 4.6–13.5). This confirmed Class II (<10% G6PD activity) G6PD deficiency. Focused history taking revealed this patient had consumed 4 bowls of fava bean soup 24 h prior to symptom onset.
      G6PD deficiency is the most common enzymatic disorder of red blood cells. The disease affects 400 million people worldwide. The Mediterranean variant typically manifests as fulminant haemolysis in response to oxidative stress. It is classically associated with favism [
      • Luzzatto L.
      • et al.
      Favism and glucose-6-phosphate dehydrogenase deficiency.
      ]. It is an X-linked recessive disorder. The prevalence in females is reported only in the context of geographical regional studies, however in all areas the disease more commonly affects males. Females may be homozygous for the condition, but this is rare. The mechanism for G6PD deficiency in heterozygous females is X-linked inactivation whereby the wild type X chromosome is silenced. The disease presents as a spectrum in females ranging from normal to severely deficient enzyme activity depending on the degree of expression of the G6PD mutation. There is evidence that the incidence of G6PD deficiency in females increases with age, this may be a consequence of age associated skewed X-inactivation.
      The blood film is a simple, cheap investigation which can aid in narrowing the differential diagnosis in cases of suspected haemolysis [
      • Bain B.J.
      Diagnosis from the blood smear.
      ]. G6PD deficiency should be considered in females presenting with haemolysis.

      Declaration of Competing Interest

      None.

      References

        • Veneri D.
        • et al.
        Blood smear, a key diagnostic tool in hematology: lessons from two cases of acute hemolysis in previously undiagnosed G6PD deficiency.
        Am J Hematol. 2016; 91: 1165-1166
        • Luzzatto L.
        • et al.
        Favism and glucose-6-phosphate dehydrogenase deficiency.
        N Engl J Med. 2018; 378: 60-71
        • Bain B.J.
        Diagnosis from the blood smear.
        N Engl J Med. 2005; 353: 498-507