PubMed · 5966390
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J F Coster, P W Helleman. 1966. Measurement or estimation.. https://doi.org/10.1159/000384489
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As a simple method for field studies to assess the cytokine-status of patients with tuberculosis (TB), the use of whole blood instead of isolated cells has advantages, especially since the risk of contamination is minimal. Therefore, cytokine production in whole blood cultures was determined using non-specific and disease-specific stimuli. Heparinized blood from healthy volunteers was either incubated in closed vacutainer tubes or in tissue culture wells after dilution in culture medium. Dose-response and kinetics were investigated for the production of TNFalpha, IL-1beta, IL-1ra, IL-10 and IFNgamma. Patients with TB and healthy individuals were examined for IFN-gamma production in whole blood. In the absence of a stimulus, the production of cytokines is negligible in whole blood cultures. LPS induces the production of TNFalpha, IL-1beta, IL-1ra and IL-10; PHA induces the production of IFNgamma and IL-10. Live BCG induces the production of proinflammatory cytokines, irrespective of tuberculin skin status. In contrast, PPD and MTB-culture filtrate induce production of IFNgamma in skin-test positive and not in skin-test negative healthy subjects. Five out of 13 patients with TB had a low antigen-specific IFNgamma production, suggestive of a minimal or absent specific T-cell response. For most purposes, cultures in closed vacutainer tubes are optimal. If one wishes to focus on T-cell cytokines or if only small volumes of blood are available, dilution of whole blood in culture medium before incubation in tissue culture wells may be preferable.
Anecdotal experience with full blood count (FBC) technology incorporating analysis of depolarized laser light (DLL) for the enumeration of eosinophils showed that malaria infection generated unusual distributions in the white cell channels. The objective of this study was to identify and define criteria for a diagnosis of malaria using this technology. To determine sensitivity, specificity, and positive and negative predictive values, 224 directed samples referred specifically for malaria were used; true positives were defined as those in which malaria was identified by microscopic and/or immunological methods. For the DLL method, positive was defined as one or more large mononuclear cell(s) for which the 90 degrees depolarized signal exceeded the 90 degrees polarized signal. To determine possible utility in a routine haematology laboratory setting, 220 random undirected FBC samples were evaluated for possible malaria infection by the DLL method. Of the 224 directed samples, 95 were malaria positive as determined by microscopic and/or immunological methods, and 129 were negative. For the DLL method, overall sensitivity was 72% (90% in the case of Black Africans), and specificity 96%. Positive and negative predictive values overall were 93% and 82% respectively. In the utility study a single positive result was identified among the 220 samples studied. This was found to be from a patient with malaria. The detection of unexpected malaria by automated screening FBC analysis could substantially lower the mortality and morbidity from unascertained infection, especially in indigenous African peoples.
BACKGROUND: Six filters were tested for their ability to remove white cells from buffy coat-depleted red cell concentrates at various temperatures. STUDY DESIGN AND METHODS: Cellselect FR, BPF4, and Sepacell filters were tested at both room temperature (RT) and 4 degrees C. The Leucoflex filter was tested only at 4 degrees C, while the Cellselect Optima Plus and Imugard filters were tested only at RT. Donor-dependent differences were excluded by pooling and subsequently dividing 9 red cell concentrates; 12 sets of experiments were performed. RESULTS: With all filters, red cell concentrates containing <5 x 10(6) white cells per unit were obtained. The lowest numbers of residual white cells were achieved with the Leucoflex (at 4 degrees C, 0.15 +/- 0.11 x 10(6), the Sepacell (at 4 degrees C, 0.23 +/- 0.14 x 10(6), the Imugard (at RT, 0.24 +/- 0.14 x 10(6), and the BPF4 (at 4 degrees C, 0.25 +/- 0.24 x 10(6); differences not significant). With the Cellselect FR, filtration at 4 degrees C resulted in 0.86 +/- 0.37 x 10(6) white cells per unit, a level not significantly different from that obtained with the BPF4 and Sepacell filters at RT (1.16 +/- 0.43 x 10(6) and 0.80 +/- 0.36 x 10(6) white cells, respectively). Filtration at RT with the Cellselect FR and Cellselect Optima Plus resulted in red cell concentrates with 1.79 +/- 0.69 x 10(6) and 2.29 +/- 0.69 x 10(6) white cells, respectively (p<0.01). CONCLUSION: All filters conformed to the current standards for white cell reduction; the process was less efficient at RT than at 4 degrees C. For routine application, the composition of the red cell concentrate, the temperature, and logistic preferences should be taken into account in the final choice of filter; before implementation, the chosen filter must be validated under routine conditions.