The following were seen on a Wright-Giemsa stained peripheral blood thin film from a 30 year old renal-transplant recipient with recurrent fevers. No travel history is available. (CLICK ON IMAGES TO ENLARGE)
Diagnosis?
Monday, June 20, 2011
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6 comments:
Looks like Ehrlichia/Anaplasma.
The objects present within the neutrophils are morphologically consistent with morulae of Anaplasma phagocytophilum or Erhlichia spp. However, since in this case the infected cells are PMNs, it's most probably infection with A. phagocytophilum. Although, RT-PCR / HRM, IF, serology, and/or other testing should be done to confirm.
I'm guessing that this unlucky individual was bitten by a tick (Ixodes spp., perhaps?). At any rate, Neelakanta et al. (2010) have recently demonstrated that Ixodes scapularis infected with A. phagocytophilum survive better in a cold environment, because Anaplasma causes the ticks to express a cryoprotectant glycoprotein. Way cool!
On a side note, since I'm a mycoplasmologist by training and I've heard it on more than one occasion, it's probably worth noting that anaplasmas and mycoplasmas are not closely related. The former are alpha-proteobacteria and the latter are low G+C% gram-positives belonging to the Class "Mollicutes."
These are Dohle bodies, or "toxic granulations" and consist of agglutinated ribosomes. They are found in infections and normally in horses and cats.
I'd go with Anaplasma; we see this fairly frequently in my part of the world, and the discrete, well-demarcated morulae -- particularly the first image -- are characteristic. In my experience toxic granulations are less well-demarcated and look like tiny clusters of granules.
E.ewingii
I say Human monocytic erhlichiosis from the bite of an Amblyomma americanum if the person was bitten some where in the South.
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