SESSION TITLE: Infectious Disease Case Report Posters I
SESSION TYPE: Case Report Poster
PRESENTED ON: Sunday, March 23, 2014 at 01:15 PM - 02:15 PM
INTRODUCTION: MonoMAC is a rare syndrome characterized by a haplodeficiency of GATA2 gene products resulting in monocytopenia, B-cell and NK-cell lymphopenia, and an increased susceptibility to atypical infections1 Since its discovery in 2010, there have been only 28 other cases described in the literature. The lack of widespread familiarity with this disease impedes early identification and often leads to mistreatment with near-fatal consequences. Here we describe a case of MonoMAC which eluded diagnosis for over one year.
CASE PRESENTATION: A 20-year-old Asian female presented with 4 weeks of fevers and cervical lymphadenopathy. Excisional biopsy ruled out tuberculosis and lymphoma. Collagen-vascular serologies were nondiagnostic. Infectious disease workup was negative except for mycobacterium avium (MAC) isolated in the sputum and stool, a positive Histoplasmosis urinary antigen, and CT-evidence of splenic abcesses. The patient was treated for these infections and eventually was discharged home on steroids based on a tentative diagnosis of Kikuchi Syndrome. However, the fevers continued over the next half-year, and the patient was hospitalized for complications from non-vasculitic panniculitis. The diagnosis was shifted to Weber-Christian Syndrome, and more steroids were given. Unfortunately, the patient then developed pneumoperitoneum from 5 separate colonic perforations, and recurrent sepsis and respiratory failure ensued from cyclical fungemia and bacteremia. The possibility of MonoMAC was raised in light of the clinical picture of disseminated MAC, histoplasmosis, and panniculitis with persistantly low CD56 levels, a surrogate marker for monocytopenia. Blood samples were sent to the National Institute of Health (NIH) that eventually confirmed the diagnosis via PCR and gene sequencing. Steroids were stopped and IL-2 and GM-CSF were given to boost hematopoesis. The NIH funded a bone marrow transplant for this patient, and she is now doing well and receiving rehabilitation.
DISCUSSION: MonoMac is a newly-discovered disorder of immunodeficiency which presents in such a variable and ambiguous fashion that it is often misdiagnosed as an inflammatory or autoimmune condition. The etiology of MonoMAC is believed to arise from an autosomal-dominant or sporatic GATA2 mutation which results in a deficiency of circulating monocytes, B-cells, and NK-cells. Due to monocyte and macrophage dysfunction, patients are not only vulnerable to intracellular pathogens such mycobacteria, fungi, and HPV, but are also prone to developing panniculitis, leukemias, and even pulmonary alveolar proteinosis1.
CONCLUSIONS: As our patient exemplifies, a heightened awareness of this new entity is important to avoid misdiagnosis and inappropriate treatment with chronic steroids given the potential of devastating iatrogenic complications.
Reference #1: Vinh et al. Blood 2010;115:1519-1529
DISCLOSURE: The following authors have nothing to disclose: Jason Schnack, Aarti Mittal, Ching-Fei Chang
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