In vitro and in vivo persistence of reticulocytes from donor red cells

BACKGROUND: Reticulocytes are important in the phenotyping of transfused patients. Reticulocytes can persist in blood units for the shelf life of the unit. STUDY DESIGN AND METHODS: Temperature dependence of reticulocyte persistence was examined in vitro at 4, 24, and 37 degrees C by using thiazole orange staining and flow cytometric analysis. Two-color flow cytometric analysis was used to evaluate the persistence of donor reticulocytes in transfused patients. RESULTS: Flow cytometric analysis using thiazole orange demonstrated that persistence of reticulocytes in units of stored CPDA-1 blood was temperature-dependent. Reticulocytes disappeared over 13 and 6 days at 24 degrees C and 37 degrees C, respectively, but at 4 degrees C the reticulocyte count changed little over 35 days. Two-color flow cytometric analysis of reticulocyte antigens was used to follow donor reticulocytes in 14 transfusion events in nine different patients. Donor reticulocytes persisted through 24 hours in 75 percent of the patients and were detectable at 48 hours in three patients. CONCLUSION: This study demonstrates that reticulocytes persist during refrigerated storage; they are detectable in the circulation of most recipients for the first 24 hours after transfusion and in the circulation of a few recipients after 48 hours. These findings may have relevance for separation techniques based on reticulocyte density in samples drawn shortly after transfusion and for evaluation of reticulocyte counts in patients with hematologic abnormalities.     

Comorbid somatic symptoms and functional status in patients with fibromyalgia and chronic fatigue syndrome: sensory amplification as a common mechanism

BACKGROUND: Somatic symptoms are common in conditions such as fibromyalgia (FM) and chronic fatigue syndrome (CFS). OBJECTIVE: Authors investigated a potential shared pathologic mechanism: a generalized perceptual abnormality where there is heightened responsiveness to varied sensory stimulation, including pain. METHOD: A composite measure of sensory sensitivity was created and compared with measures of somatic symptoms, comorbid psychological disturbances, and self-reported physical functioning in 38 patients with FM and/or CFS. RESULTS: Sensory amplification influenced physical functioning indirectly through pain intensity, and physical symptoms and fatigue also independently contributed to physical functioning. CONCLUSION: Sensory amplification may be an underlying pathophysiologic mechanism in these disorders that is relatively independent of depression and depressive symptoms.