Left shift

Abstract: Leukocytosis, a common laboratory finding, is most often due to relatively benign conditions (infections or inflammatory processes). Much less common but more serious causes include primary bone marrow disorders. The normal reaction of bone marrow to infection or inflammation leads to an increase in the number of white blood cells, predominantly polymorphonuclear leukocytes and less mature cell forms (the "left shift"). Physical stress (e.g., from seizures, anesthesia or overexertion) and emotional stress can also elevate white blood cell counts. Medications commonly associated with leukocytosis include corticosteroids, lithium and beta agonists. Increased eosinophil or basophil counts, resulting from a variety of infections, allergic reactions and other causes, can lead to leukocytosis in some patients. Primary bone marrow disorders should be suspected in patients who present with extremely elevated white blood cell counts or concurrent abnormalities in red blood cell or platelet counts. Weight loss, bleeding or bruising, liver, spleen or lymph node enlargement, and immunosuppression also increase suspicion for a marrow disorder. The most common bone marrow disorders can be grouped into acute leukemias, chronic leukemias and myeloproliferative disorders. Patients with an acute leukemia are more likely to be ill at presentation, whereas those with a chronic leukemia are often diagnosed incidentally because of abnormal blood cell counts. White blood cell counts above 100,000 per mm3 (100 x 10(9) per L) represent a medical emergency because of the risk of brain infarction and hemorrhage.

Abstract: The use of neutrophil left-shift parameters in the diagnosis of inflammatory and infective disease (ID) was evaluated. The level of C-reactive protein (CRP), currently the best quantitative parameter of inflammation, was used as the gold standard. Of 292 patients, 230 (79%) had a level of CRP of 1.0 mg/dL or greater and were classified as having inflammation, whereas 62 (21%) had normal levels. The neutrophil band count in each patient was determined by microscopic examination of 200 WBCs. The diagnostic value of the band count as an indicator for ID was evaluated in comparison to the WBC count, the neutrophil count, and the left-shift indicators of two automated hematologic analyzers, H*1 Technicon (Bayer Technicon Instruments, Tarrytown, NY) and Coulter MAX M (Coulter Electronics, Hialeah, Fla). When receiver operating characteristics were used, the band count was superior to the immature to total neutrophil count (I/T) ratio, the total WBC count, and the neutrophil count. The sensitivity and specificity in identifying ID at designated cutoff points were as follows: band count of 20% or greater of total WBC count (53% and 79%, respectively), I/T ratio of 0.25 or greater (59% and 63%), total WBC count of 9.6 x 10(6)/mL or greater (68% and 56%), and neutrophil count of 8.0 x 10(6)/mL or greater (60% and 58%). The performance of the H*1 Technicon left-shift flag was similar but slightly inferior to the band count (sensitivity, 44%; specificity, 79%), whereas the Coulter MAX M flags had a clearly higher sensitivity (79%) and lower specificity (53%). In addition, microscopic evaluation to determine the presence of reactive morphologic changes in neutrophils, such as toxic granules, Dohle bodies, and cytoplasmic vacuoles, had a high sensitivity (80%) but a low specificity (58%) in predicting ID. The diagnostic value of both microscopic and automated neutrophil left-shift parameters as indicators for ID is limited. Morphologic changes in neutrophils, however, either have a high specificity (band count) or a high sensitivity (toxic signs) in predicting ID and therefore may be a clinically useful tool.

Abstract: Background:The use of white blood cell (WBC) count and left shift in the diagnosis of appendicitis in pediatric patients is unproven. It is commonly thought that children with appendicitis have an elevated WBC count with a left shift; however, most data supporting this belief stem from studies condu