Mannose-binding protein in HIV-seropositive patients does not contribute to disease progression or bacterial infections

This study set out to investigate whether plasma mannose-binding protein (MBP) deficiency caused by mutations in the MBP gene associates with pyogenic or opportunistic infections in HIV-infected patients. Plasma samples were selected randomly from 131 HIV-infected patients followed prospectively for a period not exceeding 12 months or until death. Plasma MBP concentrations were measured by an ELISA and genotyping was determined by amplification of exon 1 of the MBP gene by polymerase chain reaction (PCR) technology, followed by restriction enzyme analysis and Southern blotting using sequence-specific oligonucleotide probes. Neither MBP concentration nor genotype was found to associate with disease progression or opportunistic infection rate. There was an unexpected increased bacterial infection rate in patients with MBP levels greater than 100 ng/ml and wild type genotype. Thus, MBP does not appear to play a role in HIV infection. MBP is an acute phase reactant and this may explain the higher levels in those with more frequent pyogenic infections.