Discussion:
Hereditary spherocytosis results in an increased risk of hemolysis with
cellular stress and splenic clearance. Patients can develop significant
intermittent hemolysis and splenomegaly or have baseline chronic
hemolysis which occasionally necessitates splenectomy for control of
severe chronic anemia. Patients and care providers are educated on the
importance of monitoring for hemolysis during febrile episodes to avoid
an array of complications from acute anemia. While hemolysis in patients
with HS and viral infection is a well-known complication of this
disorder, it has only been described in the context of
hydroxychloroquine toxicity in subjects with
COVID-19.13
Our patient, with underlying HS with
COVID-19 infection and hemolysis, emphasizes the necessity to follow
patients at risk for hemolysis closely in the setting of COVID-19. There
have been reports about patients with sickle cell disease who were
infected with COVID-19, however no case report has addressed the risk of
hemolysis in patients with hemolytic anemias.14-16
Splenectomy is often thought of as “curative” in patients with HS as
the site of red cell clearance is in the spleen. However, the red cell
membrane defect is not corrected with splenectomy and as such patients
remain at an increased risk of hemolysis with significant cellular
stress.17 Patients who have previously had an anatomic
splenectomy may have a milder course of hemolysis due to removal of the
red cell clearance organ.
There are numerous hemolysis markers that can be followed during a
hemolytic crisis. Bilirubin levels are an important marker of hemolysis
and elevation is due to the breakdown of the protoporphyrin IX ring of
heme.18 In our patient it was reassuring to note the
down trending bilirubin value prior to discharge. Ferritin is another
hemolytic marker; however, it is also an acute phase reactant and has
been found to rise in patients with severe COVID-19 infection who
develop cytokine storm.18,19 In the setting of recent
transfusions and an acute illness, a ferritin level could be elevated
and not offer insight to acute hemolysis. Lastly, we followed lactate
dehydrogenase (LDH) while hospitalized. LDH increases with hemolysis as
LDH-1 and LDH-2 are isoenzymes present in red blood cells and released
during a hemolytic event.18 We noted in our patient
that LDH trended down as the hemolytic event was resolving. This trend
has additional utility in the setting of COVID-19 in that severe
infections can progress to a cytokine storm with elevated LDH as one
potential marker.
This case highlights the importance of
monitoring hemoglobin and hemolytic markers in patients with hemolytic
disorders who are infected with COVID-19. If widespread COVID-19 testing
with nasopharyngeal swabs is initiated, children with positive results
and underlying hemolytic disorders should be screened for hemolysis. HS
has a varying severity of hemolysis and it is possible that the first
hemolytic event could take place in the setting of a COVID-19 infection.
Due to this, it is important for any provider to keep an open
differential when noticing hemolysis in the setting of COVID-19.
Conflict of Interest: The authors have no conflicts of interest
relevant to this article to disclose.
Acknowledgements: We have no additional acknowledgements to
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