Th1/Th2 balance alteration in the clinical course of a patient with pure red cell aplasia and thymoma

Thymoma associated with pure red cell aplasia: a case report and literature review

Pure red cell aplasia (PRCA) is a rare hematological complication associated with thymoma. Remission of PRCA occurs after thymectomy but can reappear after a latency period even without recurrence of thymoma. We report a case and we have reviewed the literature of thymoma associated with PRCA. Because of less number of reported cases, there have been no clinical trials investigating the immunosuppression regimen following thymectomy for thymoma associated with PRCA. After reviewing the literature, we came to a conclusion that thymectomy followed by immumosuppression with the cyclosporin-containing regimen is currently the most effective treatment.

Thymoma-Associated Paraneoplastic Autoimmune Multiorgan Syndrome-From Pemphigus to Lichenoid Dermatitis

Introduction: Paraneoplastic autoimmune multi-organ syndrome (PAMS) is a rare clinical condition characterized by variable and heterogeneous clinical phenotypes in the presence of neoplasias which largely depend on the activation of humoral and cellular immune responses. Clinically, these patients present with a spectrum of antibody-driven pemphigus-like lesions to graft-vs.-host-disease-like exanthemas with a lichenoid inflammatory infiltrate in the skin. PAMS is occasionally associated with thymoma, in which altered immune surveillance eventually leads to multiorgan autoimmunity which often includes variable cutaneous symptoms. This disorder is associated with a profound disturbance of peripheral immune tolerance against human autoantigens. Objectives: We here present a patient with relapsing thymoma who developed PAMS with several cutaneous and extracutaneous autoimmune disorders. Materials: Peripheral blood mononuclear cells (PBMC), sera, and lesional skin biopsies were obtained at different clinical disease stages. Peripheral T cell subsets were characterized phenotypically and the cytokine profile of the peripheral blood T cellular response against distinct epidermal and dermal autoantigens of the skin was analyzed by ELISpot assay. Serological screening was performed by ELISA and immunoblot analysis. Skin biopsies were subjected to immunohistochemical analysis of distinct T cell subsets. Thymoma tissue was analyzed for the presence of T regulatory cells and compared with adult thymus and indolent thymoma. Results and Conclusions: In the present case, thymoma was the cause of the observed multi-organ autoimmune syndromes as its recurrence and surgical removal was associated with the relapse and regression of the cutaneous symptoms, respectively. Initially, the patient presented with two autoimmune disorders with Th2/Th1 imbalance, myasthenia gravis (MG) and pemphigus foliaceus (PF), which regressed upon immunosuppressive treatment. Months later, the patient developed a lichenoid exanthema with a Th1-dominated skin infiltrate. Further clinical evaluation revealed the recurrence of the thymoma and the lichenoid exanthema gradually regressed upon thymectomy. Our contention that T cell recognition against distinct cutaneous autoantigens, such as desmoglein 1 (Dsg1), shifted from a Th2 to a Th1-dominated immune response could not be fully substantiated as the patient was on a stringent immunosuppressive treatment regimen. We could only observe a decrease of the initially present serum IgG autoantibodies against Dsg1. Phenotypic analysis of the associated thymoma showed a lower number of T regulatory cells compared to adult thymus and indolent thymoma, suggesting that impaired thymus-derived immune surveillance had a direct impact on the outcome of the observed cutaneous autoimmune disorders.

Pure red-cell aplasia as the presenting feature of the carcionoid tumor of the thymus: case report

Acquired pure red-cell aplasia (PRCA) is an uncommon disorder of erythrocytopoiesis that can develop in association with thymic tumors. We present the very rare case of a severely anemic 62-year-old man with PRCA and a concurrent neuroendocrine carcinoid tumor of the thymus. The anterior mediastinal thymus tumor was completely excised, and following histological and immunohistochemical analyses (showing positive staining for cytokeratin, chromogranin A, synaptophysin, and neuron-specific enolase) the diagnosis of a (grade I; T(1)N(0)M(0)) typical carcinoid tumor of the thymus was made. Postoperatively the anemia persisted despite no signs of residual tumor on CT chest. A hematological work up found: normocellularity with <0.5% erythroblasts and preserved megakaryocytopoiesis and granulocytopoiesis in a trephine biopsy; reduced numbers of Colony Forming Unit Erythroid (CFU-E) and normal numbers of Burst-Forming Unit Erythroid (BFU-E) in bone marrow colony-forming assays; a markedly increased level of serum erythropoietin; normal T and B-cell numbers with a normal CD4/CD8 ratio; and no clonal T-cell receptor -gamma and -delta gene rearrangement) The patient responded favorably to a therapeutic trial of glucocorticoid immunosuppressive treatment (prednisone 1 mg/kg/day) with a normalization of the reticulocyte count and hematocrit, suggesting an immunologic mechanism for the PRCA. Though the exact mechanisms underlying the association between the PRCA and the carcinoid tumor of the thymus remain unknown.

Impaired type I IFN-induced Jak/STAT signaling in FA-C cells and abnormal CD4+ Th cell subsets in Fancc-/- mice

The Fanconi anemia (FA) group C protein, FANCC, interacts with STAT1 following stimulation with IFN-gamma and is required for proper docking of STAT1 at the IFN-gamma receptor alpha-chain (IFN-gammaRalpha, IFN-gammaR1). Consequently, loss of a functional FANCC results in decreased activation of STAT1 following IFN-gamma stimulation. Because type I IFN receptors influence the function of type II receptors, and vice versa, we conducted experiments designed to determine whether type I IFN-induced activation of other STAT proteins is compromised in FA-C cells and found that activation of STAT 1, 3, and 5 is diminished in type I IFN-stimulated cells bearing Fancc-inactivating mutations. We also determined that the reduced activation of STATs was accompanied by significant reduction of type I IFN-induced tyrosine kinase 2 and Jak1 phosphorylation. Because tyrosine kinase 2 plays a role in differentiation of Th cells, we quantified cytokine secretion from CD4+ cells and in vitro generated CD4+ Th cell subsets from splenocytes of Fancc null mice to that of heterozygous mice and discovered reduced CD4+ IFN-gamma secretion in the Fancc-/- mouse, indicating impaired Th1 differentiation. We suggest that Fancc mutations result in a subtle immunological defect owing to the failure of FANCC to normally support Jak/STAT signaling.

Pure red cell aplasia in a Sjögren's syndrome/lupus erythematosus overlap patient

Hematological complications of systemic lupus erythematosus usually include anemia of chronic disease and peripheral destruction of blood cells. We describe the case of a young woman with Sjögren's syndrome'lupus erythematosus overlap, mother of infant with congenital heart block, complicated by pure red cell aplasia. The patient was asymptomatic until the onset of severe anemia. A serum inhibitor of erythropoiesis was detected before the onset of immunosuppression. Bone marrow examination showed a low CD4:CD8 ratio, an immune defect possibly linked with the unrestrained production of antibodies against erythroid progenitor cells.

Increased expression of c-maf in pure red cell aplasia secondary to plasma cell dyscrasia

Th2 dominancy in the peripheral T helper (Th) cell subsets were reported to be involved in the pathogenesis of pure red cell aplasia (PRCA). We encountered a PRCA case secondary to plasma cell dyscrasia that showed Th2 dominancy at the relapse of PRCA. Increased expression of c-maf, a transcriptional factor which induces Th2 differentiation of naive T-cells, and elevated expression of interleukin (IL)-4 were observed in the RNA derived from patient's bone marrow at relapse of PRCA. Following the administration of methylprednisolone which improved PRCA, normalization of Th1/Th2 ratio and decreased expression of c-maf and IL-4 were observed, which suggests that the upregulation of c-maf might have played a role in the pathogenesis of PRCA secondary to plasma cell dyscrasia.

Thymoma associated with pure red-cell aplasia: clinical features and prognosis

As information on the clinical features and prognosis of thymoma complicated by pure red-cell aplasia is limited, follow-up data on thymoma patients who had a thymectomy between 1954 and 1999 were analyzed retrospectively. Six of 166 cases were complicated by pure red-cell aplasia. In 3 of these, the pure red-cell aplasia appeared after surgical intervention. Remission was observed in 2 patients who underwent extended thymectomy. The other 4 patients subsequently died from pure red-cell aplasia. The outcome in patients with pure red-cell aplasia was poorer than that in the entire group of patients with thymoma and in those with thymoma complicated by myasthenia gravis. The possible onset of pure red-cell aplasia after thymectomy should be kept in mind during follow-up.

Th1/Th2 balance alteration in the clinical course of a patient with acute viral myocarditis

Cytokines have an important role in the pathogenesis and pathophysiology of myocarditis. In this study, subsets of peripheral helper T lymphocytes (Th) in a patient with acute viral myocarditis were analyzed by 3-color flow cytometry. During the clinical course of myocarditis, the Th1/Th2 ratio of peripheral lymphocytes changed. Th1 was dominant in the acute inflammatory phase during which levels of creatine kinase (CK) increased (day 6), then Th2 levels overtook those of Th1 in the recovery phase during which levels of CK decreased (day 13 and 20). At the time of discharge (day 35), Th1 and Th2 had normalized. Thus, it was speculated that the induction of lymphocytic myocarditis was associated with Th1 dominant status, and recovery was related to Th2 polarity. Th subset imbalances may play an important role in the pathogenesis of acute viral myocarditis and these analyses may be useful for understanding the disease activity of myocarditis.