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This chapter addresses the following Geriatric Fellowship Curriculum Milestone: #9
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Learning Objectives
Identify the most likely causes of leukopenia and leukocytosis and initiate evaluation of the most likely causes of altered white blood cell (WBC) counts in older adults.
Assess malignant versus nonmalignant causes of WBC elevation in older adults.
Recognize the value of geriatric assessment in determining outcomes for older adults with malignant WBC disorders.
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Key Clinical Points
Age is not associated with changes in WBC counts, so elevated or depressed WBC count should be evaluated as possible illness.
Drugs and infections are common causes of both increased and decreased WBC counts and should be considered when evaluating new-onset leukopenia or leukocytosis in seniors.
Older adults make up a large proportion of incident and prevalent cases of malignant WBC diseases, as well as those dying from these conditions.
The response rates and cure rates for older patients with malignant WBC diseases have lagged behind those of young adults for a number of reasons: more resistant tumor biology, presence of multiple chronic conditions, and functional impairments which decrease treatment tolerance. Underrepresentation of older adults in clinical trials remains a limitation as well.
Disease characteristics alone do not fully explain age-related outcome disparity in acute myelogenous leukemia (AML). Even among older adults with favorable disease biology, outcomes remain worse for older adults than young adults. Increased comorbidity, age-associated physiologic changes, polypharmacy, and functional and cognitive impairment complicate therapy in older adults and likely contribute to decreased treatment tolerance and shorter survival. Several small trials suggest geriatric assessment is feasible in the context of AML therapy and may better predict survival and treatment tolerance than standard clinical assessment.
Chronic lymphocytic leukemia (CLL) is the most common leukemia in the Western Hemisphere and may be expected to be encountered in a geriatric practice; median age at diagnosis is approximately 70.
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White blood cells (WBCs) provide major host defense mechanisms against invading pathogens through phagocytosis and triggering immune responses. In addition, lymphocytes provide immune surveillance against viral infections and the development of cancer, and are important mediators of disorders of the immune system. White cell disorders are usually the result of overproduction or underproduction of one or more of the WBC series, which include the granulocytes—neutrophils, basophils, and eosinophils—and/or mononuclear cells—lymphocytes and monocytes. Less frequently, WBC disorders result from WBC dysfunction despite normal number of cells. The acuity and severity of these disorders are related to the number of white cells, the subset(s) of WBC involved, their degree of maturity, and their functional capacity.
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Initial clinical manifestations of WBC disorders can vary widely but often include signs and symptoms of infection. Disorders of WBC, benign or malignant, frequently also involve abnormalities of the red blood cells (RBCs) and platelets. In these situations, the signs and symptoms of disease at presentation may include those related to anemia ...