tretinoin and Hepatitis--Autoimmune

Imbalance between effector and regulatory T-cells (Treg) underlies the loss of immune-tolerance to self-antigens in autoimmune disease. In autoimmune hepatitis type 2 (AIH-2), effector CD4 T-cell immune responses to cytochrome P450IID6 (CYP2D6) are permitted by numerically and functionally impaired Treg. Restoration of CYP2D6-specific Treg in AIH-2 would enable control over effectors sharing the same antigen specificity, leading to re-establishment of immune-tolerance. We have previously developed a protocol for generating antigen-specific Treg through co-culture with semi-mature dendritic cells presenting CYP2D6 peptides. In this study, we aimed to explore phenotypic and functional features of patient Treg compared to health, to test Treg stability under pro-inflammatory conditions, and to investigate the potential benefit of supplementation with all-trans-retinoic acid (RA) or rapamycin (RP), agents proven to enhance Treg function. We show that antigen-specific Treg from patients have comparable phenotypic and functional features to those from healthy controls, suppressing both proliferation and pro-inflammatory cytokine production by effector cells. Treg exposure to inflammatory challenge results in decreased suppressive function and up-regulation of Th1/Th2/Th17 transcription factors both in health and AIH-2. The increase of Th1 and Th17 transcription factors is limited by addition of RA in controls and Th1 expression is decreased by RP in patients. Importantly, inflammation-induced decrease in Treg function is also abrogated by RA/RP in health and RA in patients. Our data provide important information for the optimization of protocols aiming at generating antigen-specific Treg for treatment of autoimmune disease and for understanding their biology upon pro-inflammatory challenge and RP/RA supplementation.

Topics: Adolescent; Adult; Antineoplastic Agents; Child; Cytochrome P-450 CYP2D6; Female; Hepatitis, Autoimmune; Humans; Immunosuppressive Agents; Male; Sirolimus; T-Lymphocytes, Regulatory; Th17 Cells; Tretinoin

A 35-year-old man admitted to the hospital for oral hemorrhage was diagnosed with acute promyelocytic leukemia (APL). Remission from APL was achieved by induction therapy with all-trans retinoic acid (ATRA); the PML/RARA fusion gene was not detected on PCR analysis. Despite complete molecular remission, severe persistent pancytopenia, massive ascites, and renal failure were observed. The liver surface appeared rough and irregular on computed tomographic images. On the basis of the liver biopsy results, we diagnosed his condition as portal hypertension due to autoimmune hepatitis. Indocyanine green test showed good residual function of the liver, and therefore, 2 courses of consolidation therapy were administered; chemotherapy was stopped because of severe pancytopenia due to portal hypertension. Instead of continuing the consolidation therapy, maintenance therapy involving 8 rounds of ATRA monotherapy (45 mg/m(2), days1∼14) was initiated. Portal hypertension did not progress further with this maintenance therapy and therefore it was continued. The patient has been in remission from APL ever since, and no relapses have occurred since the past 5 years. These results suggest that ATRA can be used for long-term therapy in such cases.

Topics: Adult; Antineoplastic Agents; Hepatitis, Autoimmune; Humans; Hypertension, Portal; Leukemia, Promyelocytic, Acute; Male; Nuclear Proteins; Promyelocytic Leukemia Protein; Receptors, Retinoic Acid; Remission Induction; Retinoic Acid Receptor alpha; Transcription Factors; Tretinoin; Tumor Suppressor Proteins