Hypermucoviscous Klebsiella Syndrome Without Liver Abscess in a Patient With Immunoglobulin G2 Immune Deficiency

BACKGROUND: Hypermucoviscous Klebsiella pneumoniae (HMVKP) emerged as a cause of invasive infections in South-East (SE) Asia. It has become the most common cause of liver abscess in that region, and it is a significant causative organism in endogenous endophthalmitis and meningitis. During the past decade, cases of this uniquely virulent organism have been reported outside of SE Asia, with a propensity to affect individuals of SE Asian descent. Cases have been reported from North America including Canada. METHODS: We report a case of a patient of Filipino descent living in Canada who presented with recurrent HMVKP bacteremia in the absence of pyogenic liver abscess or other localized metastatic Klebsiella infection. RESULTS: Investigations identified an immunoglobulin (Ig)G2 deficiency and low IgM indicating potential common variable immunodeficiency, and administration of intravenous immunoglobulins was associated with prevention of further recurrences. CONCLUSIONS: To our knowledge, this is the first report of HMVKP associated with predisposing antibody deficiency.