P0712 A CASE OF MORTAL NECROTIZING FASCIITIS IN A DIABETIC PATIENT

Parvovirus B19 is a single-stranded DNA virus. Clinical manifestations associated with acute infection are due to attachment of the virus to the P-antigen receptor on erythroid progenitor cells, and to immune-complex deposition in the skin and joints. Asymptomatic transient reticulocytopenia and a decrease in hemoglobin occur in most patients with B19 infection. We report a case of a 54-year old female patient with scleroderma and chronic low-dose steroid treatment who presented with a fever of unknown origin of 1-months duration. History, physical examination and radiological investigations were non-diagnostic for the source of fever. A decrease in hemoglobin from 12.4 g/dL to 10.3 g/dL was observed, with red cells indicative of a normocytic, normochromic anemia. White blood cell and platelet counts remained intact. Further investigation revealed a mild hemolytic picture with LDH – 945 U/L and haptoglobin – 16 mg/dL with a negative direct Coomb’s antibody test. Peripheral blood and bone marrow examination revealed a borderline lymphocytosis (10) with an abnormally high percentage (38) of these cells having an atypical morphology (large granular lymphocytes). These large granular lymphocytes were CD3and displayed markers for true natural killer cells – CD56+, CD16+, and CD11b. The basis of the patient’s clinical presentation was unclear until serology for acute parvovirus infection (IgM) was confirmed positive. The patient also tested positive for parvovirus B19 DNA on PCR of the bone marrow material. A diagnosis of acute parvovirus B19 infection was rendered. Fever resolved spontaneously within 1 month of its onset. The patient was followed up in an out-patient setting for 6 months with the following observations: – Spontaneous resolution of the anemia and the hemolytic picture. – Seroconversion to IgG for parvovirus B19. – Decrease in number of true NK cells in peripheral blood. In conclusion, parvovirus B19 is a ubiquitous infection that in the majority of affected patients remains asymptomatic. Benign, transient (< 6 months duration) NK lymphocytosis has been described in viral infections and autoimmune disease. Furthermore, isolated case reports exist of autoimmune hemolytic anemia in acute B19 infection. Our report indicates that parvovirus B19 may be associated with a Coomb’s negative hemolytic anemia and a transient appearance of true NK cells in the peripheral blood and bone marrow.