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.