Leukemoid Reaction in a Patient With Severe COVID-19 Infection

A Predictive Algorithm for Discriminating Myeloid Malignancies and Leukemoid Reactions

BACKGROUND

Adults presenting with a neutrophil-predominant leukocytosis (white cell count >50,000/μL) often necessitate urgent medical management. These patients are diagnosed with either acute presentations of chronic myeloid malignancies or leukemoid reactions, yet accurate models to distinguish between these entities do not exist. We used demographic and lab data to build a machine learning model capable of discriminating between these diagnoses.

METHODS

The medical record at a tertiary care medical center was queried to identify adults with instances of white counts greater than 50,000/μL and >50% neutrophils from 2000 to 2021. For each patient, a full set of demographic and lab values were extracted at the time of their first presentation with a white count >50,000/μL. We generated a series of models in which the parameters most predictive of myeloid malignancies were identified, and a supervised machine learning approach was applied to the dataset.

RESULTS

Our best model-using a support vector machine algorithm-produced a sensitivity of 96% and a specificity of 95.9% (area under the curve = 0.982) for identifying myeloid malignancies. We also identified a clinically meaningful and significant disparity in outcomes based on diagnosis-a 6-fold increase in 12-month mortality in those diagnosed with leukemoid reactions.

CONCLUSIONS

These findings need to be validated but fill an unmet need for timely and accurate diagnosis in the setting of profound, neutrophil-predominant leukocytosis and support the use of predictive models as a means to improve patient outcomes.

Leukemoid Reaction With Severe Diabetic Ketoacidosis

A leukemoid reaction is a rare condition characterized by an elevation in white blood cell count exceeding 50,000 cells/μL in response to severe medical conditions, which can mimic the presentation of chronic myeloid leukemia (CML). Distinguishing between leukemoid reaction and CML depends on a thorough clinical history and comprehensive laboratory evaluation. We present a case of leukemoid reaction associated with severe diabetic ketoacidosis, where the patient's white blood cell count returned to the normal range after the correction of hyperglycemia and electrolyte imbalances.

Case mistaken for leukemia after mRNA COVID-19 vaccine administration: A case report

BACKGROUND

Following the global outbreak of coronavirus disease 2019 (COVID-19), unlike other vaccines, COVID-19 vaccines were developed and commercialized in a relatively short period of time. The large-scale administration of this vaccine in a short time-period led to various unexpected side effects, including severe cytopenia and thrombosis with thrombocytopenia syndrome. Despite many reports on adverse reactions, vaccination was necessary to prevent the spread of COVID-19; thus, it is essential to understand and discuss various cases of adverse reactions after vaccination.

CASE SUMMARY

A 77-year-old woman was administered the second dose of Pfizer mRNA COVID-19 vaccine. After vaccination she experienced fever, myalgia, and weakness. Antibiotics were subsequently administered for several days, but there was no improvement in the symptoms. The patient showed severe thrombocytopenia and leukocytosis. Thoracic and abdominopelvic computed tomography showed no infection related findings, but splenomegaly and cirrhotic liver features were observed. A large number of immature cells were observed in the peripheral blood smear; thus, bone marrow examination was performed for acute leukemia. However, there were no abnormalities. The patient recovered after administration of hepatotoxins and transfusion treatment for cytopenia and was diagnosed with an adverse reaction to COVID-19 vaccination.

CONCLUSION

Adverse reactions of vaccination could be mistaken for hematologic malignancies including leukemia. We report a patient with leukocytosis following COVID-19 vaccination.

Leukemoid Reaction in a Severe COVID-19 Patient

Leukemoid reaction is defined by a leukocyte level above 50 x 10³/µL with a predominance of mature neutrophils and the presence of immature granulocytic forms in the peripheral blood (left shift). We report a case of a 36-year-old woman with severe coronavirus disease 2019 (COVID-19) infection admitted to the ICU with a leukocytosis of 70.9 x 10³/µL white blood cells (WBC) throughout her hospitalization. A left shift with bandemia along with toxic granulations was also noticed and further investigation excluded more commonly known causes. A presumptive diagnosis of leukemoid reaction was made secondary to COVID-19 infection; however, it could not be confirmed since workup for lymphoproliferative disorders could not be performed as the patient passed away. The leukemoid reaction could be associated with severe COVID-19 infection; however, more data are needed to evaluate this association.