Case Study MICR Hematology Spring, 2011 Case # 5 Hee Jin Kim, Hooman Nikizad and Arthur Omuro

Case Summary Gregory, a healthy 25-year-old man, has a routine physical examination and laboratory studies for new employment. He is asymptomatic. Laboratory Findings: ◦ Total white blood cell count: 30,000 x 10 9 /L ◦ The differential white blood cell count:  7% blasts, 3% promyelocytes, 25% myelocytes, 10% metamyelocytes, 5% bands, 25% segmented neutrophils, 10% basophils, 5% eosinophils, and 10% lymphocytes. Cytogenetic analysis: ◦ All cells had the karyotype of 46,XY,t(9;22)(q34:q11.2)

Key Information Pointing to Diagnosis Significant increase in white blood cell count: 30,000 x 10 9 /L Left shift: ◦ 7% blast, 3% promyelocytes, 25% myelocytes, 10% metamyelocytes Increased number of granulocytes: ◦ 10% basophils, 5% eosinophils Philadelphia Chromosome

The Diagnosis for Case # 5 Increased WBC count and the left shift in the WBC in the peripheral blood suggest the possibilities of : ◦ Chronic Myelocytic Leukemia, Leukemoid Reaction, and essential thrombocythemia. Cytogenetic finding of the Philadelphia chromosome (46, XY, t(9;22)(q34:q11.2)) suggests that Gregory has Chronic Myelocytic Leukemia.

Pathophysiology of Chronic Myelocytic Leukemia (CML) Philadelphia Chromosome t(9;22): reciprocal translocation on the long arms of chromosome 9 and 22 ◦ BCR gene from chromosome 22 fuses with ABL gene on chromosome 9. ◦ BCR/ABL produces a tyrosine kinase, inhibits DNA repair, and enhances cell division. ◦ As a result of the Philadelphia Chromosome that exists in the stem cells, the dividing abnormal cells are clonal.

Diagnostic Tests for CML Cytogenetic karyotype studies detect the presence of Philadelphia chromosome in 90% of CML case. The remaining 5-10% of CML with undetectable translocation can be checked with more sensitive DNA studies such as RT-PCR or fluorescent in situ hybridization (FISH). Other tests may be performed post bone marrow transplant to provide information regarding the recipient’s cells: ◦ FISH, RT-PCR, Leukocyte Alkaline Phosphatase scoring

Therapy for Chronic Myelocytic Leukemia Treatment: ◦ Single agent chemotherapy ◦ Bone marrow transplant after eradication of the leukemic cell mass is the best therapy – however, cells with Philadelphia chromosome will remain in the bone marrow  3 months after receiving a bone marrow transplant from his sister (46, XX), the karyotype of the patient was completely replaced by that of the sister’s, pointing to a successful transplant. ◦ New drug: Gleevec

Prognosis for Chronic Myelocytic Leukemia 5 Years after the transplant, cytogenetic analysis revealed: ◦ 5 cells: 46, XX ◦ 15 cells: 47, XY,+8,t(9:22) (q34:q11.2),i(17q) Chromosome 8 has a trisomy while chromosome 17 has become an isochromosome. Based on the abundance of abnormal cells, the patient is not in great condition.

Prevention of Chronic Myelocytic Leukemia CML is not an inherited disease. It is rather acquired disease, often with unknown cause (95%). However, some identified leukemogens that are known to increase the risk of translocation and formation of Philadelphia chromosome are: ◦ Ionizing radiation, cytotoxic drugs (especially alkylating agents) and biologically active chemicals such as benzene. Avoiding exposure to these agents might help preventing CML.

Take Home Message The diagnosis is: Chronic Myelogenous Leukemia Typical symptoms are: fatigue, fever, malaise, weight loss, sweating, bone aches, fullness in upper abdomen, bleeding, petechiae The cause of the disease is: unknown, exposure to radiation and chemicals Diagnostic tests include: CBC, bone marrow biopsy, FISH, RT-PCR Treatment is: bone marrow transplant, drugs, chemotherapy Prognosis is: variable dependent on treatment and progression of disease Prevention is: avoid radiation/chemicals

References Harmening, Denise M. “Clinical Hematology and Fundamentals of Hemostasis.” Philadelphia, Pennsylvania: FA Davis, 2009: 373 – 380 Meng, Chin Y. “Cytogenetics and Molecular Studies in Chronic Myeloid Leukemia.” St. Clements University Dissertation, McQueen, Nancy. Class Lecture. Hematology. CSULA, 19 May Branford, S. et al. “Diagnosis and Monitoring of Chronic Myeloid Leukemia by Qualitative and Quantitative RT-PCR.” Methods Mol Med.2006: 69-92

Point Spread Case summary5 Key Information pointing to Diagnosis15 Diagnosis5 Pathophysiology of the disease25 Diagnostic tests10 Therapy5 Prognosis5 Prevention5 Take home message5 Are all questions addressed?10 Appearance5 Presentation skills (individual)5 Total100