Cytokines in Lyme borreliosis

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I have a 'TH1 Lyme.pdf'

Linköping University Medical Dissertations No. 938

Cytokine responses in human Lyme borreliosis

The role of T helper 1-like immunity and aspects of

gender and co-exposure in relation to disease course

Sara Jarefors

SUMMARY AND CONCLUSION

It seems that an initial Th1-type response with a later switch to a Th2-

response is compatible with a subacute prognosis of Lyme borreliosis. On the

other hand, a slowly increasing Th1-response and lack of Th2 might

correspond to a chronic or prolonged disease course.

The reason behind why some individuals show an inadequate response to

Borrelia is probably not one single factor but is likely multi

factorial. The

type of infectious species plays a part due to differences in invasive

ability.

The immunological status of the individual at the time of infection

might also

affect the specific response to the Borrelia spirochete and thereby also the

outcome of the disease. Women, after going through menopause, seem to

have an immune response that is not benificial for combating a Borrelia

infection. Furthermore, a previous infection by a different pathogen can

possibly alter the immune response.

Even though a weak Th1-response appears to be involved in the cause of

chronic Lyme borreliosis it would probably be to oversimplify the underlying

mechanism. The focus should not be solely on the Th1-Th2 balance since

many other factors also have to be considered in the complicated network of

immunological responses. The involvement of regulation and the possible

contribution of Treg to the pathogenesis of Lyme borreliosis have only just

begun to be investigated.

The finding in paper III, that there might be a gender difference in the

immune response, illustrates the importance of careful consideration when

selecting the patient material for an immunological experimental study. The

different groups to be compared should be both age and gender matched to

limit the variations in cytokine secretion between men and women. It is

never

possible to eliminate all confounding factors when working with a human

material but the ones within our control should be limited.

The results and findings in this thesis do not solve the mystery behind

chronic Lyme borreliosis but might be a piece of the giant jigsaw puzzle

that

is Lyme borreliosis.