Mannose-binding lectin deficiency does not appear to predispose to cryptococcosis in non-immunocompromised patients.
While most patients with cryptococcosis have obvious cellular immune deficiency, a minority have no apparent predisposing factors. However, in the latter there may be subtle innate immune system deficiencies which go unrecognized. Mannose-binding lectin (MBL) deficiency is associated with increased susceptibility to infectious diseases and may predispose to cryptococcosis, particularly when it disseminates to the central nervous system (CNS) in apparently immunocompetent patients. MBL function and levels, as well as MBL2 genotype were determined in 36 HIV-negative cryptococcosis patients (25 with CNS involvement) using C4 deposition and mannan-binding ELISA. MBL deficiency was defined using C4 deposition level < 0.2 U/microl or mannan-binding level < 0.5 microg/ml. MBL results were compared between patients with cryptococcosis and healthy controls and among the cryptococcosis patients according to the site of their disease. There was no difference in MBL function, mannan-binding level or increase in the frequency of MBL deficiency or low producing MBL2 genotypes in any of these comparisons. Patients with CNS cryptococcosis were no more likely to be MBL deficient than those with non-CNS disease. It appears that MBL deficiency is not associated with cryptococcosis in non-immunocompromised hosts. Beta errors consequent on the small number of patients studied may account for the lack of association.
Eisen
Damon P
DP
Centre for Clinical Research Excellence in Infectious Diseases, Victorian Infectious Diseases Service, Royal Melbourne Hospital, Victoria, Australia. damon.eisen@mh.org.au
Dean
Melinda M
MM
O'Sullivan
Matthew V N
MV
Heatley
Sue
S
Minchinton
Robyn M
RM
D000293:Adolescent; D000328:Adult; D000368:Aged; D020314:Central Nervous System Fungal Infections / Q000235:genetics / Q000276:immunology; D003181:Complement C4 / Q000378:metabolism; D003453:Cryptococcosis / Q000235:genetics* / Q000276:immunology; D004198:Disease Susceptibility; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D018023:HIV Seronegativity; D006801:Humans; D007121:Immunocompetence; D008297:Male; D037601:Mannose-Binding Lectin / Q000172:deficiency* / Q000235:genetics; D008875:Middle Aged
D003181:Complement C4; C445619:MBL2 protein, human; D037601:Mannose-Binding Lectin