False-Positive Nonstructural Protein 1 Antigen in a Patient with Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia: A Case Report with Literature Review.

Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.Division of Hematology, Department of Medicine, Rajavithi Hospital, Bangkok, Thailand.Division of Hematology, Department of Medicine, Rajavithi Hospital, Bangkok, Thailand.Hospital for Tropical Diseases, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.Division of Hematology, Department of Medicine, Rajavithi Hospital, Bangkok, Thailand.

The American journal of case reports. 2021;:e928865

Abstract

BACKGROUND A rapid investigation of dengue viral infection is needed for physicians who manage patients with suspected dengue infection. The nonstructural protein 1 (NS1) test kit is commonly used to diagnose patients with acute febrile illness in dengue-endemic countries, although this test kit can yield false-positive results. The Dengue NS1 test kit mostly relies on cross-reaction among febrile illness patients with other viral infections rather than malignancies. CASE REPORT A 52-year-old male patient presented with 3 days of fever, intermittent gum bleeding, weight loss, and mucocutaneous bleeding. He was transferred to a second hospital with acute febrile illness. Both dengue NS1 antigen test kits were positive from the 2 hospitals where he was previously treated. Fever and cytopenia persisted, and then the dengue RT-PCR test was performed to establish the cause of illness. A peripheral blood smear was reviewed and showed blast cells. A bone marrow examination was done to test for the compatibility of lymphoblastic leukemia. The flow cytometry test showed B cells ALL with Philadelphia-positive chromosome. Finally, the result of the dengue RT-PCR test was negative. CONCLUSIONS Our patient presented with fever and viral-like illness, but he was finally diagnosed with Ph+ ALL. We demonstrated the first case of false-positive dengue NS1 antigen in a Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) patient. Moreover, we reviewed the literature to gather information on false-positive results using the dengue NS1 test kit. The dengue NS1 test kit is useful and produces reliable clinical findings, especially in patients with hematological malignancies.

Methodological quality

Publication Type : Case Reports ; Review

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