In vivo and in vitro studies on Anaplasma phagocytophilum infection of the myeloid cells of a patient with chronic myelogenous leukaemia and human granulocytic ehrlichiosis.

AIMS: The occurrence of human granulocytic ehrlichiosis (HGE) in a patient with chronic myelogenous leukaemia (CML) provided an opportunity to study whether Anaplasma phagocytophilum, the aetiological agent of HGE, infects mature or immature cells, both in vivo and in vitro. METHODS: Diagnosis of HGE was confirmed by culture, polymerase chain reaction (PCR), detection of intragranulocytic inclusions, and serology. The infection rates of different myelogenous stages of granulocytic differentiation were determined by microscopy. Anaplasma phagocytophilum infection of the bone marrow was analysed by PCR, culture, and microscopy. In addition, the in vitro growth of A phagocytophilum in the patient's granulocytes and in HL-60 cells (a promyelocytic leukaemia cell line) was compared. RESULTS: Pretreatment blood smears showed that mature granulocytic cells had a higher infection rate with A phagocytophilum than did immature cells. In the original inoculation of the patient's cells into HL-60 cells to isolate A phagocytophilum, the bacterium grew faster in the patient's leukaemic cells than in HL-60 cells. Anaplasma phagocytophilum inclusions were rarely seen in bone marrow granulocytes and PCR was negative. In vitro, two A phagocytophilum isolates grew faster in the patient's granulocytes than in HL-60 cells. CONCLUSIONS: The superior growth in CML cells compared with HL-60 cells suggests that A phagocytophilum preferentially infects mature granulocytes. The higher infection rate of the patient's mature versus immature granulocytes before treatment and the minimal level of infection of the patient's bone marrow support this. It is possible that the primary site of infection in HGE is the peripheral mature granulocytic population.

Expedited human immunodeficiency virus testing of mothers and newborns with unknown HIV status at time of labor and delivery.

New York State introduced the first statewide program in the U.S. of expedited HIV testing (48-hour turn-around results) of mothers with unknown HIV status at the time of labor or delivery and their newborns on August 1, 1999. We evaluated the results of this program during its first 5 months at Lincoln Medical and Mental Health Center (Lincoln Hospital) in the Bronx, New York. There were 1,274 total live birth deliveries between August 1 and December 31, 1999. The HIV infection status of 539 mothers (42.3%) was unknown to medical providers in the labor-delivery suite, either due to lack of testing during the current pregnancy or unavailability of HIV documentation at the time of delivery. During labor and delivery, a total of 462 (85.7%) mothers with unknown HIV status consented to expedited HIV testing (Single Use Diagnostic System for HIV-1 antibody or SUDS). The newborns of 77 mothers (14.3%) who did not consent were tested immediately after birth. Seventeen tested positive for HIV-1 antibody by the SUDS test. The results of 10 of these infants (58.8%) were subsequently confirmed positive for HIV-1 antibody by Western Blot analysis. This new rapid HIV testing program facilitated early diagnosis of these previously unknown HIV-exposed infants, although the low positive predictive value of the test in our community calls for careful communication of these results pending confirmation.