Mannose-binding lectin levels and major infections in a cohort of very long-term survivors after allogeneic stem cell transplantation.
BACKGROUND
Life-threatening infections are a major cause of death after allogeneic stem cell transplantation. Complement Mannose-binding lectin is a key component of innate immunity. Functional deficiency of mannose-binding lectin due to genetic polymorphism is frequent. Previous reports showed conflicting results with respect to the influence of functional mannose-binding lectin deficiency on infectious risk after allogeneic stem cell transplantation. The aim of this study was to clarify the impact of low mannose-binding lectin levels on infectious risk in a unique cohort of very long-term survivors after stem cell transplantation.


METHODS
Incidence of major infections was evaluable in 43 out of 44 very long-term survivors (over ten years) and studied retrospectively in relation to mannose-binding lectin serum concentrations.


RESULTS
Recipients with mannose-binding lectin levels below 1,000 ng/mL were at increased risk to suffer from one or more major infections (P=0.002) during entire follow up. Infectious susceptibility was increased after neutrophil recovery, particularly until 24 months (Hazard Ratio 3.4) with sustained effects afterwards (Hazard Ratio 2.9). Mannose-binding lectin serum concentrations below 1,000 ng/mL were independently associated with major infections after neutrophil recovery (P=0.009). In subgroup analyses occurrence of severe herpes virus infections in particular was associated with significantly lower mannose-binding lectin levels (P=0.02).


CONCLUSIONS
Our findings indicate that low mannose-binding lectin levels may predict markedly increased susceptibility to severe infections with sustained effects even late after allogeneic stem cell transplantation. Determinations of mannose-binding lectin status should therefore be included into pre-transplantation risk assessment.
Osthoff
Michael
M
Laboratory of Clinical Immunology, Department of Biomedicine, University Hospital Basel, Hebelstrasse 20, CH-4031 Basel, Switzerland. mosthoff@uhbs.ch
Rovó
Alicia
A
Stern
Martin
M
Danner
Doris
D
Gratwohl
Alois
A
Tichelli
André
A
Trendelenburg
Marten
M
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects / Q000379:methods* / Q000706:statistics & numerical data; D006561:Herpes Simplex / Q000097:blood* / Q000209:etiology; D006801:Humans; D008297:Male; D037601:Mannose-Binding Lectin / Q000097:blood* / Q000235:genetics; D008875:Middle Aged; D016016:Proportional Hazards Models; D017741:Survivors; D014184:Transplantation, Homologous
D037601:Mannose-Binding Lectin