TNF-α inhibition in the setting of undiagnosed HIV infection: a call for enhanced screening guidelines.

BACKGROUND: Despite the risks of immunosuppression, recommendations regarding screening for HIV infection prior to initiation of biologic therapies targeting common rheumatologic disorders, including inflammatory bowel disease (IBD) and inflammatory arthritides, are limited. Few cases of patients started on biologics while living with undiagnosed HIV infection have been reported. METHODS: We report three cases of patients initiated on biologics in the absence of recent or concurrent HIV screening who developed refractory disease or unanticipated complications and were later found to have undiagnosed chronic HIV infection. RESULTS: In Case 1, a 53-year-old MSM with negative HIV testing 2 years prior presented with presumed rheumatoid arthritis. He did not respond to methotrexate, so adalimumab was started. HIV testing to evaluate persistent symptoms was positive 9 months later; CD4+ T-cell count was 800 cells/µl. Antiretroviral therapy (ART) resulted in resolution of symptoms, which were attributed to HIV-associated arthropathy. In Case 2, a 55-year-old woman with injection drug use in remission and no prior HIV testing presented with hidradenitis suppurativa. She started infliximab and methotrexate therapy with good response. After she developed weight loss and lymphopenia, an HIV test was positive; CD4+ T-cell count was 334 cells/µl. Biologic hidradenitis suppurativa therapy was discontinued, with subsequent poor hidradenitis suppurativa control. In Case 3, a 32-year-old MSM with no prior HIV testing presented with presumed IBD; infliximab and steroids were started. Symptoms progressed despite IBD-directed therapy, and he was diagnosed with extensive Kaposi sarcoma with visceral and cutaneous involvement, likely exacerbated by immunosuppression. HIV testing was positive; CD4+ T-cell count was 250 cells/µl. Kaposi sarcoma initially worsened due to ART-associated immune reconstitution inflammatory syndrome. He is now improving with systemic chemotherapy and ART. HIV-associated Kaposi sarcoma is presumed to be the underlying diagnosis. CONCLUSION: All three patients had elevated risk for HIV infection, and two had final diagnoses attributed to chronic HIV infection, not warranting therapeutic immunosuppression. Screening for HIV infection prior to initiation of biologic therapy should be incorporated into clinical practice guidelines.

Lysosomal retargeting of Myoferlin mitigates membrane stress to enable pancreatic cancer growth.

Lysosomes must maintain the integrity of their limiting membrane to ensure efficient fusion with incoming organelles and degradation of substrates within their lumen. Pancreatic cancer cells upregulate lysosomal biogenesis to enhance nutrient recycling and stress resistance, but it is unknown whether dedicated programmes for maintaining the integrity of the lysosome membrane facilitate pancreatic cancer growth. Using proteomic-based organelle profiling, we identify the Ferlin family plasma membrane repair factor Myoferlin as selectively and highly enriched on the membrane of pancreatic cancer lysosomes. Mechanistically, lysosomal localization of Myoferlin is necessary and sufficient for the maintenance of lysosome health and provides an early acting protective system against membrane damage that is independent of the endosomal sorting complex required for transport (ESCRT)-mediated repair network. Myoferlin is upregulated in human pancreatic cancer, predicts poor survival and its ablation severely impairs lysosome function and tumour growth in vivo. Thus, retargeting of plasma membrane repair factors enhances the pro-oncogenic activities of the lysosome.

A Leishmania major response locus identified by interval-specific congenic mapping of a T helper type 2 cell bias-controlling quantitative trait locus.

The propensity of naive CD4 T cells to become T helper (Th) type 2 cells correlates with susceptibility to infection by the protozoal parasite Leishmania major. Using genetic linkage analysis, we earlier identified Dice1 as a Th2 cell bias-controlling quantitative trait locus on chromosome 16. Using interval-specific congenic mapping, we now resolve Dice1 into two independent genetic loci, Dice1.1 and Dice1.2, which control Il4 expression from naive Th cells and thereby indirectly control Th2 cell bias. Interestingly, only one of the two congenic intervals containing Dice1.1 and Dice1.2, respectively, also contained an L. major response locus, indicating that L. major responsiveness can be insensitive to determinants that influence Th2 cell bias by controlling naive T cell Il4 expression. These results lay the groundwork for identifying the Dice1.1 and Dice1.2 genes controlling naive T cell Il4 expression and L. major responses, and for testing whether these control other Th2 cell-dependent processes such as worm expulsion, allergic asthma, and dermatitis.