[Recurrent atypical mycobacterial infections in the adult: think of autoantibodies against interferon-gamma !]

INTRODUCTION

Disseminated non-tuberculosis mycobacterial infections are associated with a defect of the cellular immune response. They have been mainly reported in AIDS patients. Cases related to the presence of anti-interferon-γ autoantibodies are rare.

CASE REPORT

We report a non HIV-infected 45-year-old Thai woman, with a past medical history of Graves' disease. She presented with recurrent disseminated and severe non-tuberculous mycobacterial infections that were related to the production of anti-interferon-γ autoantibody. The diagnosis was suspected in the presence of a negative interferon-γ release assay (IGRA) including with the positive control, and evidenced by the identification of specific antibodies.

CONCLUSION

Anti-interferon-γ autoantibody production is a rare cause of non tuberculous mycobacterial infection. Such a mechanism should be suspected in non HIV-infected patients and especially in those having an Asiatic ethnicity or an associated immune disorder. A negative IGRA (including with the positive control) is a reliable diagnostic tool and should be completed with the identification of specific autoantibodies.

[Total skin electron beam therapy for early-stage mycosis fungoides: immediate results and long-term follow-up in 68 patients]

BACKGROUND

Our aim was to evaluate the efficacy of total skin electron beam therapy (TSEB) in the management of early-stage mycosis fungoides in order to assess its position in relation to other skin-directed therapies.

PATIENTS AND METHODS

A retrospective study of 68 patients (30 in stage T1 and 38 in stage T2).

RESULTS

The median treatment duration was 6 weeks. Three months after the end of TSEB, a complete clinical response occurred in 66 patients (97%). The most marked effects of acute toxicity included localized ulcerations in 13 patients (13.2%) not requiring hospitalization. Mean follow-up was 6.5 years (1.6 to 28.7). The overall survival rates at 5 and 10 years were 86% and 71%, respectively. Thirty-nine patients (57.4%) experienced relapse with a mean disease-free interval of 1.8 years. The disease-free survival rates at 5 and 10 years were 41% and 31%, respectively. This rate was higher when TSEB was performed early (p=0.031). Twenty-one years after TSEB, only one case of cutaneous malignancy (basal cell carcinoma) was noted.

DISCUSSION

Because of its high response rates and rapidity of action, TSEB should be considered as first-line therapy in the management of early-stage mycosis fungoides.

Polyethylenimine-mediated in vivo gene transfer of a transmembrane superantigen fusion construct inhibits B16 murine melanoma growth

Immunotherapy has been proposed as a therapeutic strategy in advanced-stage melanomas in which other therapeutic options have little effect. The Staphylococcus enterotoxin A (SEA) has been used to stimulate an antitumoral immune response but its use is hampered by severe systemic side effects. Here, we show that SEA can be targeted to melanoma cells to limit these side effects. More specifically, we used a nonviral vector, the cationic polymer, polyethylenimine (PEI), to express a transmembrane SEA fusion construct (pSEA-TM) in B16F10-induced subcutaneous melanoma in mice. The efficacy of this in vivo transfection was enhanced by concomitant infusion of epinephrine to induce local vasoconstriction. In these conditions, repeated injections of pSEA-TM/PEI complexes elicited a significant response, as evidenced by tumor growth inhibition, without systemic adverse effects. T cell infiltration of the tumors, together with positive lymphocyte proliferation tests, suggested local and systemic immune responses. Altogether, PEI-mediated targeting of SEA to melanoma tumor cells in vivo efficiently stimulates the antitumor immune response without inducing the side effects observed with systemic administration of SEA.