Can Exposure to Jet Fumes Lead to Acute Leukemia?.

Introduction:

AML/MDS is usually diagnosed in older adults with median age of 64 in patients at time of diagnosis, after occupational exposure to organic solvents, such as benzene, or previous therapeutic exposure to alkylating agents, topoisomerase inhibitors, or ionizing radiation.

We are presenting a case of AML/MDS in a young female without previous history of exposure to alkylating agents or ionizing radiation, but with history of exposure to jet fumes.

Case Report:

This is a 30-year old Carribean woman, chronic smoker, ethanol user, employed for eight years at the airport, working on the ground with heavy direct exposure to jet fumes, who presented with 2 weeks of progressive dyspnea, fatigue and bone pains. She was found to have pancytopenia, hemoglobin 2.8 gm/dL, platelets 37,000/mL, and neutrophils 1100/mL. Peripheral smear showed many nucleated red blood cells and blasts. Bone marrow aspiration was “dry” and bone biopsy revealed hypercellularity with dysplastic changes in erythrocyte, granulocyte and megakaryocytic lineages with 46% blasts. Flow cytometry of peripheral blood showed positivity for CD13, CD33, CD34, and CD117 and HLA-DR with complex cytogenetics showing deletions involving chromosomes 5q, 7q, 12p, 20q and loss of chromosome 17. Fluorescent in situ hybridization (FISH) studies were negative for t(15,17), MLL, t(8,21), inv(16) seen in classical de novo AML. FISH also did not show abnormalities in the probe regions 5q31, 7q31, 8cen and 20q12 of chromosomes 5, 7, 8 and 20 classically seen in de novo MDS. The blast cell morphology suggested acute myelocytic leukemia on a background of myelodysplasia. Precise FAB subtype was not possible in the absence of special stains like myeloperoxidase, and specific and non-specific esterase stains. The patient was treated with two induction courses of cytosine arabinoside and idarubicin. With persistence of 4.5% blasts on the peripheral blood and severe bone marrow aplasia, she was referred for allogeneic stem cell transplantation, in view of failed induction remission and complex cytogenetics at presentation.

Conclusion:

Case-control studies of leukemia demonstrated only slight increase in risk of disease after many years of occupational or chemical exposures. More studies to investigate leukemia incidence in airport employees, or even communities near airports are needed.