Loss of cytomegalovirus-specific immunological memory in a patient with thymoma.
Cytomegalovirus (CMV) retinitis is a re-activation infection associated with severely impaired T cell-mediated immunity. We describe a patient with long-standing Crohn's disease and thymoma who developed severe CMV retinitis. While thymoma can be associated with impaired humoral immunity and a quantitative CD4+ T helper cell deficiency, these were not evident in our patient. However, more detailed investigation of anti-CMV responses showed absence of specific T cell responses to CMV antigen. Normal CMV seropositive controls have detectable proliferation and interferon-gamma production by T cells in response to stimulation with CMV antigen, but this was absent in this patient both during the acute infection and in convalescence. Other measures of T cell function were normal. Since CMV retinitis is due to reactivation of latent CMV infection, it appears that selective loss of CMV-specific immunity had occurred, perhaps secondary to a thymoma. The causes of thymoma-associated immune impairment are not understood, but this case demonstrates that selective defects can occur in the absence of global T cell impairment. Opportunistic infections should therefore be suspected in patients with thymoma even in the absence of quantitative immune deficiencies.
Huissoon
A P
AP
Department of Immunology, Queen's Medical Centre, Nottingham. Huissoa@heartsol.wmids.nhs.uk
Davies
G
G
Cox
R A
RA
Sloper
C M L
CM
Thomson
B J
BJ
Robins
R A
RA
D000368:Aged; D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral; D003587:Cytomegalovirus / Q000276:immunology*; D017726:Cytomegalovirus Retinitis / Q000209:etiology / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007156:Immunologic Memory; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000096:biosynthesis; D008213:Lymphocyte Activation; D008297:Male; D009894:Opportunistic Infections / Q000209:etiology / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D013945:Thymoma / Q000150:complications / Q000276:immunology*; D013953:Thymus Neoplasms / Q000150:complications / Q000276:immunology*
D000914:Antibodies, Viral; D000956:Antigens, Viral; D007074:Immunoglobulin G; D007371:Interferon-gamma