TY - JOUR
T1 - Human ehrlichiosis
T2 - Hematopathology and immunohistologic detection of Ehrlichia chaffeensis
AU - Stephen Dumler, J.
AU - Dawson, Jacqueline E.
AU - Walker, David H.
N1 - Funding Information:
From the Department of Pathology, University of Texas Medical Branch, Galveston, TX; and the Division of Viral and Rickettsial Diseases, Centers for Disease Control, Atlanta, GA. Accepted for publication July 20, 1992. Supported in part by the National Institute for Allergy and Infectious Diseases grant no. AI31431. Presented in part at the 81~ Annual Meeting of the United States and Canadian Academy of Pathology, Atlanta, GA, March 14-19,1992. Kq words: ehrlichia, hematopathology, granuloma, immunohis-tology. Address correspondence and reprint requests to J. Stephen Dumler, MD, Department of Pathology, University of Maryland School of Medicine, 10 S Pine St, Baltimore, MD 21201. Copyright 0 1993 by W.B. Saunders Company 0046-8177/93/2404-0009$5.00/O
PY - 1993/4
Y1 - 1993/4
N2 - Human ehrlichiosis is a recently described zoonosis caused by a rickettsia that infects leukocytes. Most patients have fever, headache, chills, and myalgias and develop leukopenia, thrombocytopenia, anemia, and elevations in serum hepatic aminotransferases. The cause of the peripheral leukopenia and thrombocytopenia is not known. We studied peripheral blood smears, bone marrow aspirates, and bone marrow biopsy specimens from patients with serologically proven ehrlichiosis to characterize the pathologic changes associated with leukopenia or thrombocytopenia, to detect the presence of immunohistologically demonstrable ehrlichiae, and to establish the infected host target cell(s). Specimens were obtained from 12 patients, and immunohistology for Ehrlichia chaffeensis was performed on tissue sections, aspirated bone marrow, and peripheral blood smears. Mean leukocyte and platelet counts available for nine patients were white blood cell count 3,300/μL (range, 1,100 to 10,300/μL) and platelets 61,000/μL (range, 40,000 to 82,000/μL). Findings included myeloid hyperplasia (eight cases), megakaryocytosis (seven cases), granulomas (eight cases), marrow histiocytosis (one case), myeloid hypoplasia (one case), pancellular hypoplasia (one case), and normocellular marrow (two cases). Morulae of E chaffeensis were detected in four of 10 cases examined by immunohistology. Most ehrlichiae were detected within histiocytes, although morulae were rarely present within lymphocytes. Leukopenia, thrombocytopenia, or pancytopenia apparently most often results from peripheral sequestration or destruction; however, hypoplasia of marrow elements is present occasionally. Immunohistologic demonstration of E chaffeensis offers a direct means for establishing the etiologic diagnosis. These observations show the relatively frequent occurrence of bone marrow granulomas and suggest that infection of cells of the reticuloendothelial system may participate in the pathogenesis of human ehrlichiosis.
AB - Human ehrlichiosis is a recently described zoonosis caused by a rickettsia that infects leukocytes. Most patients have fever, headache, chills, and myalgias and develop leukopenia, thrombocytopenia, anemia, and elevations in serum hepatic aminotransferases. The cause of the peripheral leukopenia and thrombocytopenia is not known. We studied peripheral blood smears, bone marrow aspirates, and bone marrow biopsy specimens from patients with serologically proven ehrlichiosis to characterize the pathologic changes associated with leukopenia or thrombocytopenia, to detect the presence of immunohistologically demonstrable ehrlichiae, and to establish the infected host target cell(s). Specimens were obtained from 12 patients, and immunohistology for Ehrlichia chaffeensis was performed on tissue sections, aspirated bone marrow, and peripheral blood smears. Mean leukocyte and platelet counts available for nine patients were white blood cell count 3,300/μL (range, 1,100 to 10,300/μL) and platelets 61,000/μL (range, 40,000 to 82,000/μL). Findings included myeloid hyperplasia (eight cases), megakaryocytosis (seven cases), granulomas (eight cases), marrow histiocytosis (one case), myeloid hypoplasia (one case), pancellular hypoplasia (one case), and normocellular marrow (two cases). Morulae of E chaffeensis were detected in four of 10 cases examined by immunohistology. Most ehrlichiae were detected within histiocytes, although morulae were rarely present within lymphocytes. Leukopenia, thrombocytopenia, or pancytopenia apparently most often results from peripheral sequestration or destruction; however, hypoplasia of marrow elements is present occasionally. Immunohistologic demonstration of E chaffeensis offers a direct means for establishing the etiologic diagnosis. These observations show the relatively frequent occurrence of bone marrow granulomas and suggest that infection of cells of the reticuloendothelial system may participate in the pathogenesis of human ehrlichiosis.
KW - ehrlichia
KW - granuloma
KW - hematopathology
KW - immunohistology
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U2 - 10.1016/0046-8177(93)90087-W
DO - 10.1016/0046-8177(93)90087-W
M3 - Article
C2 - 8491479
AN - SCOPUS:0027195142
SN - 0046-8177
VL - 24
SP - 391
EP - 396
JO - Human pathology
JF - Human pathology
IS - 4
ER -