RESUMO
A 31-year-old woman developed low-grade fever and pain and swelling of the masticatory muscles. A T2-weighted magnetic resonance image showed high signal intensity in these muscles. Coxsackie B3 and echo 30 viruses were detected from a nasopharyngeal swab and feces, respectively. The clinical symptoms accompanied a marked decline in the serum immunoglobulin G level with progressive eosinophilia. Her symptoms disappeared by 8 weeks after onset. She was diagnosed as having masticator myopathy, which has rarely been reported in humans. The present case suggests that masticator myopathy is associated with coxsackie or echo virus infection.
Assuntos
Músculos da Mastigação/patologia , Doenças Musculares/patologia , Adulto , Infecções por Coxsackievirus/complicações , Infecções por Coxsackievirus/patologia , Infecções por Coxsackievirus/virologia , Infecções por Echovirus/complicações , Infecções por Echovirus/patologia , Infecções por Echovirus/virologia , Fezes/virologia , Febre/etiologia , Humanos , Imunoglobulina G/sangue , Imageamento por Ressonância Magnética , Masculino , Doenças Musculares/tratamento farmacológico , Doenças Musculares/virologia , Nasofaringe/virologia , Peptídeo Hidrolases/uso terapêuticoRESUMO
The recurrent translocation t(1;3)(p36;q21) is associated with myelodysplastic syndrome (MDS)/acute myelogenous leukemia (AML) characterized by trilineage dysplasia, especially dysmegakaryopoiesis and a poor prognosis. Recently, the two genes involved in this translocation have been identified: the MEL1 gene at 1p36.3, and the RPN1 gene at 3q21. The breakpoint in RPN1 is centromeric to the breakpoint cluster region of the inv(3) abnormality. Because the MEL1 transcript is detected only in leukemic cells with t(1;3)(p36;q21), ectopic expression of MEL1 driven by RPN1 at 3q21 is thought to contribute to the pathogenesis of t(1;3)(p36;q21) leukemia. However, the precise breakpoint in the patients has not yet been identified. With fluorescence in situ hybridization analysis by use of BAC/PAC probes, we identified the breakpoint at 1p36.3 in three MDS/AML patients with t(1;3)(p36;q21): within the first intron of the MEL1 gene (one patient) or within a 29-kb region located in the 5' region of MEL1 (two other patients). We detected several sizes of MEL1 transcript in two patients including the first patient, although we have not yet clarified whether MEL1 transcripts were different among the patients and whether a truncated MEL1 transcript was expressed in the first patient. This patient showed an unusual clinical profile, repeating progression to overt leukemia and conversion to MDS three times during the 29-month survival period, which might be related to a different molecular mechanism in this patient.
