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White cell differential count and influenza A

2005; Elsevier BV; Volume: 118; Issue: 11 Linguagem: Inglês

10.1016/j.amjmed.2005.04.030

1555-7162

Aaron Lupovitch,

interferon and immune responses

We read with considerable interest the recent report of Cunha, McDermott and Mohan on the prognostic importance of lymphocytopenia in West Nile encephalitis.1Cunha B.A. McDermott B.P. Mohan S.S. Prognostic importance of lymphopenia in West Nile encephalitis.Am J Med. 2004; 117: 710-711Abstract Full Text Full Text PDF PubMed Scopus (14) Google Scholar Following the influenza A epidemic of 2003-2004 we posed a somewhat different but related question for another viral infection: Does the white cell differential count offer clues for the diagnosis of influenza A? The answer offers insights similar to those of Cunha et al.We looked at the 5 types of peripheral blood leukocytes, including lymphocytes in absolute rather than relative units, and can expand on the above authors’ findings in a generic sense of leukocyte response to acute viral inflammation.We selected 50 consecutive patients that presented in the emergency department with signs and symptoms of influenza with the diagnosis confirmed by a rapid direct immunochromatographic test for influenza A viral antigen. Seventeen of the patients had a complete blood count with differential count (Table 1). These were performed using an automated analyzer that examined 6000-8000 cells as the basis for the differential cell count. Results can be summarized as follows:Table 1Leukocyte differential cell counts in patients with influenza A infectionCase no.Age (years)WBC (/uL)Neutrophils (/uL)Lymphocytes (/uL)Monocytes (/uL)Eosinophils (/uL)Basophils (/uL)10.265007804670910707020.610 4005520374011400031.1520039007305700041.311 2005710381016800051.577003540362046008061.78400395038605900075.011 800929012501210010810.011 80010 50071059000911.011 900964086013500201018.081006890890320001147.014 60012 4101750440001254.055004290550660001361.0810067908804000101465.0910076509305500101570.078006860470470001681.0600041401140720001783.070005600700630070Reference ranges Neutrophils3000-7000/uL Lymphocytes Adult1000-3000/uL Child3000-7000/uL Monocytes300-800/uL Eosinophils100-600/uL Basophils0-150/uLWBC = white blood cell count. Open table in a new tab NeutrophilsIn two thirds of the patients (12 of 17), results were within the reference range and increased in 5. No immature cells were noted.LymphocytesApproximately one half of the patients (9 of 17) had lymphocytopenia. The remaining 8 patients had levels in the low normal range. This included 6 children whose reference range is higher.MonocytesTwo thirds (13 of 17) were within the reference range and 4 increased.EosinophilsAll patients except for a 2-month-old infant, case 1, had essentially no eosinophils in circulation.BasophilsAll were within the reference range.The most characteristic pattern seen was low normal or lymphocytopenia and eosinopenia.We re-examined the data presented by Cunha et al, and converted their lymphocyte findings to absolute lymphocyte values (Table 2). The findings are essentially the same as we noted in patients with influenza A virus infection. As noted by the authors, all had low or decreased numbers of lymphocytes. One of the two fatalities had marked lymphocytopenia. However, the second patient fatality did not. A correlation with severity of disease may exist as postulated by the authors but is not apparent in this small series.Table 2Absolute lymphocyte counts in patients with West Nile virus encephalitis (modified from Cunha et al)Patient no.Age (years)Leukocyte count (/mm3) Lymphocytes (%)AbsoluteOther cells18013 000791012 09027589001089080103745900211857824776900117596141568860013111874826419500201900760074611 40010114010 2608618100181458664298517 30014242214 878105411 100161776932411695000168004200121717 2009154815 652138069001611045796 Open table in a new tab The cell group of nonlymphocytes is most certainly predominantly neutrophils. It shows the prominent variation noted also in the group of influenza A patients. Perhaps Cunha et al could re-examine their findings for concurrent eosinopenia. If present, it would help substantiate that the common pattern of reaction for these two viral infections includes low normal or actual lymphocytopenia with eosinopenia. This pattern has a low degree of diagnostic specificity but would have a negative or exclusionary value when absent.Notable in both series is the variability in neutrophil response. Cause and clinical significance are not apparent with the limited data available. Future investigators may wish to evaluate the viruses’ abilities to stimulate or mute the host’s acute inflammatory response and possible clinical implications. We read with considerable interest the recent report of Cunha, McDermott and Mohan on the prognostic importance of lymphocytopenia in West Nile encephalitis.1Cunha B.A. McDermott B.P. Mohan S.S. Prognostic importance of lymphopenia in West Nile encephalitis.Am J Med. 2004; 117: 710-711Abstract Full Text Full Text PDF PubMed Scopus (14) Google Scholar Following the influenza A epidemic of 2003-2004 we posed a somewhat different but related question for another viral infection: Does the white cell differential count offer clues for the diagnosis of influenza A? The answer offers insights similar to those of Cunha et al. We looked at the 5 types of peripheral blood leukocytes, including lymphocytes in absolute rather than relative units, and can expand on the above authors’ findings in a generic sense of leukocyte response to acute viral inflammation. We selected 50 consecutive patients that presented in the emergency department with signs and symptoms of influenza with the diagnosis confirmed by a rapid direct immunochromatographic test for influenza A viral antigen. Seventeen of the patients had a complete blood count with differential count (Table 1). These were performed using an automated analyzer that examined 6000-8000 cells as the basis for the differential cell count. Results can be summarized as follows: WBC = white blood cell count. NeutrophilsIn two thirds of the patients (12 of 17), results were within the reference range and increased in 5. No immature cells were noted. In two thirds of the patients (12 of 17), results were within the reference range and increased in 5. No immature cells were noted. LymphocytesApproximately one half of the patients (9 of 17) had lymphocytopenia. The remaining 8 patients had levels in the low normal range. This included 6 children whose reference range is higher. Approximately one half of the patients (9 of 17) had lymphocytopenia. The remaining 8 patients had levels in the low normal range. This included 6 children whose reference range is higher. MonocytesTwo thirds (13 of 17) were within the reference range and 4 increased. Two thirds (13 of 17) were within the reference range and 4 increased. EosinophilsAll patients except for a 2-month-old infant, case 1, had essentially no eosinophils in circulation. All patients except for a 2-month-old infant, case 1, had essentially no eosinophils in circulation. BasophilsAll were within the reference range.The most characteristic pattern seen was low normal or lymphocytopenia and eosinopenia.We re-examined the data presented by Cunha et al, and converted their lymphocyte findings to absolute lymphocyte values (Table 2). The findings are essentially the same as we noted in patients with influenza A virus infection. As noted by the authors, all had low or decreased numbers of lymphocytes. One of the two fatalities had marked lymphocytopenia. However, the second patient fatality did not. A correlation with severity of disease may exist as postulated by the authors but is not apparent in this small series.Table 2Absolute lymphocyte counts in patients with West Nile virus encephalitis (modified from Cunha et al)Patient no.Age (years)Leukocyte count (/mm3) Lymphocytes (%)AbsoluteOther cells18013 000791012 09027589001089080103745900211857824776900117596141568860013111874826419500201900760074611 40010114010 2608618100181458664298517 30014242214 878105411 100161776932411695000168004200121717 2009154815 652138069001611045796 Open table in a new tab The cell group of nonlymphocytes is most certainly predominantly neutrophils. It shows the prominent variation noted also in the group of influenza A patients. Perhaps Cunha et al could re-examine their findings for concurrent eosinopenia. If present, it would help substantiate that the common pattern of reaction for these two viral infections includes low normal or actual lymphocytopenia with eosinopenia. This pattern has a low degree of diagnostic specificity but would have a negative or exclusionary value when absent.Notable in both series is the variability in neutrophil response. Cause and clinical significance are not apparent with the limited data available. Future investigators may wish to evaluate the viruses’ abilities to stimulate or mute the host’s acute inflammatory response and possible clinical implications. All were within the reference range. The most characteristic pattern seen was low normal or lymphocytopenia and eosinopenia. We re-examined the data presented by Cunha et al, and converted their lymphocyte findings to absolute lymphocyte values (Table 2). The findings are essentially the same as we noted in patients with influenza A virus infection. As noted by the authors, all had low or decreased numbers of lymphocytes. One of the two fatalities had marked lymphocytopenia. However, the second patient fatality did not. A correlation with severity of disease may exist as postulated by the authors but is not apparent in this small series. The cell group of nonlymphocytes is most certainly predominantly neutrophils. It shows the prominent variation noted also in the group of influenza A patients. Perhaps Cunha et al could re-examine their findings for concurrent eosinopenia. If present, it would help substantiate that the common pattern of reaction for these two viral infections includes low normal or actual lymphocytopenia with eosinopenia. This pattern has a low degree of diagnostic specificity but would have a negative or exclusionary value when absent. Notable in both series is the variability in neutrophil response. Cause and clinical significance are not apparent with the limited data available. Future investigators may wish to evaluate the viruses’ abilities to stimulate or mute the host’s acute inflammatory response and possible clinical implications.