RESUMEN
Hemophagocytic lymphohistiocytosis (HLH) is a rare disease that occurs due to unregulated immune system activation induced by various causes including infection and cancer. In this article, we report a case of a 67-year-old male with history of small cell lung cancer who developed HLH triggered by methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. The patient was initially admitted for septic shock and gastrointestinal bleed. Further workup showed that the patient met criteria for HLH diagnosis as he was positive for 5 of the 8 parameters. Unfortunately, the patient's condition worsened and he eventually expired. With this case, we wish to draw attention to the fact that sepsis due to MRSA bacteremia can be a trigger for HLH.
Asunto(s)
Bacteriemia/complicaciones , Linfohistiocitosis Hemofagocítica/etiología , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Choque Séptico/complicaciones , Anciano , Resultado Fatal , Humanos , Linfohistiocitosis Hemofagocítica/diagnóstico , MasculinoRESUMEN
In vertebrates, specific regions of skin crucial for interaction with and manipulation of elements in the environment are characterized by specialized epidermis. Regions of specialized epidermis show distinct patterns of cellular differentiation and express specific keratins that provide an increased ability to withstand mechanical strain. The nipple, which must endure the mechanical strain of nursing, is a type of specialized epidermis. The entire ventral skin of the keratin 14 promoter driven PTHrP mouse provides a model for nipple development. To identify novel markers for this specialized epidermis, we have used two-dimensional (2-D) gels, mass spectrometric protein identification, Western blotting and immunohistochemistry to compare intermediate filament preparations from the nipple-like K14-PTHrP ventral skin to that of wild-type littermates. We identified 64 spots on 2-D gels that were increased in expression in the nipple-like skin of the female K14-PTHrP mouse and 11 spots that were elevated in the wild type. Microsequencing suggested that K17 and epiplakin were among the proteins with the greatest increase in expression in the K14-PTHrP ventral skin. Using Western blots and immunohistochemistry, we evaluated the expression of these proteins as well as K6 in the wild-type nipple, K14-PTHrP ventral skin and wild-type ventral skin. In addition, we found that the expression of K6 was minimally changed in the pregnant and lactating nipple, but the expression of a previously identified marker, K2e, was reduced during lactation. Using a model of the mechanical strain induced by nursing, we found that K2e but not K6 expression was responsive to this condition. The identification of epidermal markers and their expression patterns will provide insight into the cellular differentiation patterns of the nipple and the underlying epidermal-mesenchymal interactions that direct this differentiation.