ABSTRACT
To estimate the rate of asymptomatic exposure to Bordetella pertussis antigens in the German adult population and to evaluate the stability of antibodies to these antigens, antibody levels against Bordetella antigens and their variability over time were measured in German adult blood donors. One hundred forty-six regular blood donors (41 females, 105 males) were tested repeatedly for antibodies of isotypes IgG and IgA to pertussis toxin, filamentous hemagglutinin (FHA) and pertactin over a period of 2-5 years. Overall, 86% and 56% had IgG or IgA antibodies to pertussis toxin, respectively, 100% and 92% had IgG or IgA antibodies to FHA, respectively, and 83% and 93% had IgG or IgA antibodies to pertactin, respectively. One significant titer increase of both IgG anti-FHA and IgG anti-pertactin, one of IgG anti-FHA, and two of IgA anti-FHA as well as one significant decrease of IgG anti-pertussis toxin were observed during an observation period of 480.5 person-years. Antibody concentrations in men and women were not different. The data show that the level of antibodies to pertussis toxin, FHA, and pertactin remains stable over several years. Furthermore, depending on the definition of serological evidence, the rate of significant increases or decreases suggesting unrecognized exposure to Bordetella antigens was estimated to be between <0.2 and 1.0 per 100 person-years in the population studied.
Subject(s)
Antibodies, Bacterial/blood , Bordetella pertussis/immunology , Adhesins, Bacterial/immunology , Adult , Bacterial Outer Membrane Proteins/immunology , Blood Donors , Female , Hemagglutinins/immunology , Humans , Immunoglobulin A/blood , Immunoglobulin G/blood , Male , Pertussis Toxin , Virulence Factors, Bordetella/immunologyABSTRACT
A new fast sequence type, called COSESS/INSESS, is described. The steady state for COSESS is coherent but incoherent for INSESS. COSESS/INSESS combine the contrast behavior of fast imaging with steady-state free precession (FISP) and fast low angle shot (FLASH), respectively, to the robustness of spin-echo (SE) sequences with regard to susceptibility and field inhomogeneities. In contrast to other fast sequences such as rapid spin-echo excitation (RASEE), fast low angle spin echo with short echo time (FATE) or the missing pulse sequence, which also uses a spin echo, COSESS/ INSESS can additionally handle time-dependent disturbances arising from eddy currents, hysteresis or B(zero) instability. The acquisition time is 2 to 3 times longer than with gradient-based steady-state sequences. The principle of echo generation is evaluated and shows a superposition of several subechoes in the spin echo. Different solutions were elaborated to attain a coherent superposition of sub-echo signals for COSESS. Signal and contrast behavior were investigated both by simulations and experiments and demonstrate the performance of COSESS/INSESS.
