Thymic Epithelial Tumor-Associated Cytopenia: A 10-Year Observational Study in France

Treatment strategy for acquired pure red cell aplasia: a systematic review and meta-analysis

The treatment of autoimmune acquired pure red cell aplasia (aPRCA) is challenging. Guidelines are based on expert recommendations in the absence of controlled trials. We assessed the efficacy of the main treatment strategy through a systematic review and meta-analysis using MEDLINE, EMBASE, and the Cochrane Library up to September 2022. The overall response rate (ORR) was pooled using random-effects models. In total, 24 observational studies (19 retrospective, median follow-up of 48 months) encompassing 753 patients (49% male) were included. Primary aPRCA represented 57% of the cases. The risk of bias was moderate to high using the ROBINS-I tool. Substantial heterogeneity (I2 > 50%) was retrieved. Corticosteroids as monotherapy as first-line treatment (186 patients, 13 studies) provided an ORR of 47% (95% confidence interval [CI], 34-60). Cyclosporine A was the most frequently used immunosuppressant agent (384 patients, 18 studies), providing an ORR of 74% (95% CI, 66-82) with a similar ORR in first- (73%) and second-line (76%) treatment and when cyclosporin was used as monotherapy (83%) or with corticosteroids (77%). A total of 112 patients (10 studies) received cyclophosphamide, with an ORR of 49% (95% CI, 35-64), which was higher when cyclophosphamide was combined with corticosteroids (48%) and used in second-line treatment (58%) than in monotherapy (31%), and in first-line treatment (44%). Sirolimus use was reported only after cyclosporine A failure and provided an ORR of 87% (95% CI, 68-100; 64 patients, 3 studies). Substantial uncertainty remains regarding the best treatment strategy in the absence of high-quality evidence. This study was registered on the PROPERO database as #CRD42022360452.

[Pure red cell aplasia: Diagnosis, classification and treatment]

Pure red cell aplasia (PRCA) is a rare anemia characterised by profound reticulocytopenia caused by a marked reduction in bone marrow erythroblasts, without abnormalities in other blood lineages. Blackfan-Diamond anemia is an inherited ribosomopathy responsible for a hereditary form of PRCA. Acquired PRCA are separated in primary and secondary forms, including Parvovirus B19 infection, thymoma, lymphoproliferative disorders, autoimmune diseases (lupus) and drug-induced PRCA. The pathophysiology of PRCA is not fully understood and involves both humoral and T lymphocyte autoreactive cells. In Parvovirus B19-related PRCA, treatment is based on polyvalent immunoglobulins. Thymectomy for thymoma is mandatory but results in prolonged remission in a limited number of cases. The therapeutic strategy is based on expert opinion: corticosteroids in monotherapy provide few sustained responses. The choice of an additional immunosuppressant drug is guided by the presence of an underlying disease. In most cases, cyclosporine A is the first choice providing the best response rate but requires a concentration monitoring (150 to 250 ng/mL). The second choice is cyclophosphamide in large granular lymphocyte leukaemia. Sirolimus (mTOR inhibitor) seems to be a promising option especially in refractory cases. Transfusion independence is the main objective. If the patient receives numerous red blood cell transfusions (> 20 packs), iron overload assessment is crucial to initiate an iron chelation. A retrospective and prospective national cohort (EPIC-F) has been set up and is now available to include each case of PRCA to improve the knowledge of this disease and to optimize the therapeutic strategy.

Immunological signature of patients with thymic epithelial tumors and Good syndrome

Background

Thymic epithelial tumors (TETs) are frequently accompanied by Good Syndrome (GS), a rare immunodeficiency, characterized by hypogammaglobulinemia and peripheral B cell lymphopenia. TETs can be also associated to other immunological disorders, both immunodeficiency and autoimmunity.

Methods

In this study, we enrolled TET patients with GS to address differences between patients with or without associated autoimmune diseases (AD). We analyzed the immunophenotype from peripheral blood of these patients focusing on selected immune cell subsets (CD4+T cells, CD8+T cells, T regulatory cells, NK cells, B-cells, monocytes, eosinophils, basophils, neutrophils) and serum levels of cytokines, chemokines and growth factors.

Results

We observed higher number of leucocytes, in particular lymphocytes, B lymphopenia and lower number of T regulatory cells in TET patients with associated AD compared to TET patients without AD. In the group of TET patients with AD, we also observed increased serum levels of IL-15, VEGF, IP-10, GM-CSF, IL-6, and MIP-1α. Thus, we identified considerable differences in the lymphocyte profiles of TET patients with and without ADs, in particular a reduction in the numbers of B lymphocytes and T-regulatory cells in the former, as well as differences in the serum levels of various immune modulators.

Conclusions

Although the pathogenic mechanisms are still unclear, our results add new knowledge to better understand the disease, suggesting the need of surveilling the immunophenotype of TET patients to ameliorate their clinical management.

Pure Red Cell Aplasia and Other Haematological Diseases Associated With Thymoma: A Case Series and Systematic Review

Background: Thymoma-associated haematological diseases (HDs), such as pure red cell aplasia (PRCA) and Good's syndrome, are extremely rare, and due to the paucity of large-scale studies, the characteristics, remission after thymectomy, and long-term evaluation remain undetermined.

Methods: We retrospectively assessed patients with thymoma and associated HDs from Jan 2005 to Dec 2020. All patients received thymectomy and/or additional treatments for HDs. A comparison with thymoma-associated myasthenic gravis (MG), and a systematic review from PubMed/MEDLINE and Embase were conducted.

Results: In the median follow-up of 56 months, 130 patients were enrolled. Patients with thymoma-associated MG (n = 46) and HDs [n = 8; PRCA (n = 5), PRCA and Good's syndrome (n = 2) and autoimmune haemolytic anaemia (n = 1)] were evaluated. Patients with MG had a significantly higher remission rate after thymectomy (50 vs. 17%; p = 0.0378) as compared to those with other autoimmune diseases. Two of seven patients with PRCA experienced remission with thymectomy alone, and an additional two patients achieved remission with thymectomy plus immunosuppressive therapy (IST). In the systematic review, 60 studies (case reports, n = 46; case series including the present study, n = 14) were evaluated. Forty-four percent of patients were diagnosed with PRCA after thymoma, and 61% achieved remission with thymectomy plus IST; however, Good's syndrome was unaffected.

Conclusions: Our study indicates that patients with thymoma-associated autoimmune diseases other than MG have a lower remission rate than those with MG. Remission of thymoma-associated PRCA can be achieved by thymectomy and IST. This study provides insight into extremely rare but puzzling autoimmune manifestations.

Management of thymoma associated autoimmune pure red cell aplasia: Case report and systematic review of the literature

Pure red cell aplasia (PRCA) is a rare paraneoplastic syndrome observed in 2-5 % of thymomas. Literature reports great variability in its management. Based on an illustrative clinical case, we present a systematic literature review whose main objective is to evaluate the therapeutic management of PRCA. The literature search was performed based on the PICO method in the Medline and Scopus databases. The reference clinical case concerns a 51-year-old woman with stage IVa thymoma. After initial response to chemotherapy, a locoregional progression occurred with PRCA development that responded favorably under second line chemotherapy. The patient finally died in a context of bicytopenia with febrile neutropenia. The systematic review covers 135 articles published between 1950 and 2019. Thymectomy alone or in combination with other therapies showed a 31 % complete remission (CR) rate for PRCA of, whereas none was reported with anti-tumor treatments without thymectomy. Among immunomodulatory therapies, cyclosporin gave the highest percentage of CR (74 %). Finally, the combination of thymectomy and immunomodulatory treatments showed a CR rate of 45 %. Thymectomy appeared to be the most effective anti-tumor treatment for PRCA. Immunomodulatory therapies, particularly cyclosporine, are shown effective, but the risk of infectious complications must be considered. The optimal place of anti-tumor and immunomodulatory therapies against PRCA has yet to be determined.

Clinical manifestations and long-term prognosis of Good syndrome: Results from a single-center cohort study from China

OBJECTIVE

To describe clinical features and long-term prognosis in patients with Good syndrome (GS).

METHODS

We retrospectively reviewed medical records of GS patients at Peking Union Medical College Hospital from January 2001 to May 2019. Data regarding clinical manifestations and treatments were collected. Patients were routinely followed-up via clinical and telephone interviews, and survival analysis was performed with Kaplan-Meier analysis.

RESULTS

Twenty-four patients were identified, including eight males and 16 females, with a median age at diagnosis of 58 years (interquartile range [IQR], 52-62 years). Twelve patients (50%) had autoimmune manifestations. Multi-organ involvements included musculoskeletal (37.5%), respiratory (33.3%), gastrointestinal (29.2%), hematologic (29.2%) systems, et.al. Infections were detected in 23 (95.8%) patients, mostly located in lung (69.6%), blood (26.1%), and gastrointestinal tract (21.7%). Thymectomy was performed in 23 patients, with the most common histology of type AB (10, 47.6%). Twenty-one patients were consecutively followed-up with a median follow-up of 84 (IQR, 48-116) months and 11 (52.4%) died, mainly due to infection (8/11, 72.7%). The 5- and 10-year survival rates were 90% (95% confidence interval [CI], 77.8-100%) and 38.5% (95% CI, 19.6-75.5%), respectively.

CONCLUSION

GS patients tended to present with various infections and autoimmune manifestations. The 10-year survival rate from the Chinese population was poor, mainly due to infections.

Systemic lupus erythematosus associated with thymoma: A fifteen-year observational study in France

OBJECTIVE

To describe the clinical, biological and pathological characteristics of patients with the association of SLE and thymic epithelial tumors (TET) in a retrospective multicenter series.

METHODS

Cases diagnosed in France between 2000 and 2015 were collected after a call for observations from the French network for thymic epithelial tumors (RYTHMIC database) and the French National Society of Internal Medicine (SNFMI).

RESULTS

Fourteen patients were identified, the majority were women (93%). The median age at diagnosis of lupus was 43.5 [range: 30-66] years and 43.5 [range: 26-73] years at diagnosis of thymoma. TET required chemotherapy and/or radiotherapy complementary to surgery in >90% cases. Lupus was diagnosed before, simultaneously, or after diagnosis of thymoma in 6, 3 and 5 cases, respectively. Among the lupus manifestations, joint involvement was predominant (78.6%), followed by autoimmune cytopenia (35.7%), cutaneous affections (28.6%), serositis (28.6%) and renal involvement (21.4%). SLE was associated with one or more AID in 5/14 patients. These characteristics were compared with those from 17 patients identified in the literature. Among them, joint and skin involvement as well as pleural/pericardial effusions occurred in >50%. SLE was controlled by prednisone and hydroxychloroquine in the majority of cases, but 7 out of 31 patients had an immunosuppressant.

CONCLUSION

The association of SLE and TET is rare, and its clinical profile seems to be distinguished by the frequency of cytopenias. The management of these patients is complicated by the need to treat cancer, lupus and/or associated autoimmune diseases.

Aplastic Anemia and Good Syndrome in a Heavily Treated Stage IV Thymoma Patient: A Case Report and Review of the Literature

Thymoma is an uncommon slowly growing neoplasm. It usually presents with paraneoplastic syndromes including the immunodeficiency syndrome called Good syndrome and hematological disorders. Pure red cell aplasia is a well-recognized complication of thymoma, and aplastic anemia is very rare in association with GS. We report a case of GS in a heavily treated patient with stage IV thymoma associated with a pure red cell aplasia and an amegakaryocytic thrombocytopenia that evolved into an AA and provide an up-to-date review of the relevant literature. This is the first case of the association of GS and AA with the coexistence of a heavily treated stage IV thymoma. The fatal outcome was not related to the progression of the thymoma, but rather to the severe infectious complications. The combination of lymphopenia and hypogammaglobulinemia typical of GS, coupled to the neutropenia, caused by bone marrow failure, was the main predisposing factor for the unfavourable outcome.

[Thymoma and autoimmune diseases]

The association between thymoma and autoimmunity is well known. Besides myasthenia gravis, which is found in 15 to 20% of patients with thymoma, other autoimmune diseases have been reported: erythroblastopenia, systemic lupus erythematosus, inflammatory myopathies, thyroid disorders, Isaac's syndrome or Good's syndrome. More anecdotally, Morvan's syndrome, limbic encephalitis, other autoimmune cytopenias, autoimmune hepatitis, and bullous skin diseases (pemphigus, lichen) have been reported. Autoimmune diseases occur most often before thymectomy, but they can be discovered at the time of surgery or later. Two situations require the systematic investigation of a thymoma: the occurrence of myasthenia gravis or autoimmune erythroblastopenia. Nevertheless, the late onset of systemic lupus erythematosus or the association of several autoimmune manifestations should lead to look for a thymoma. Neither the characteristics of the patients nor the pathological data can predict the occurrence of an autoimmune disease after thymectomy. Thus, thymectomy usefulness in the course of the autoimmune disease, except myasthenia gravis, has not been demonstrated. This seems to indicate the preponderant role of self-reactive T lymphocytes distributed in the peripheral immune system prior to surgery. Given the high infectious morbidity in patients with thymoma, immunoglobulin replacement therapy should be considered in patients with hypogammaglobulinemia who receive immunosuppressive therapy, even in the absence of prior infection.

Moving Immune Checkpoint Blockade in Thoracic Tumors beyond NSCLC

SCLC and malignant pleural mesothelioma (MPM) are historically characterized by a disappointing lack of significant therapeutic breakthroughs for novel agents, and both malignancies represent true unmet medical needs. Given the promising results of anti-cytotoxic T-lymphocyte associated protein-4 and anti-programmed cell death-1/programmed death ligand-1 antibodies in the treatment of advanced NSCLCs, these immune checkpoint inhibitors are now also under investigation in SCLC and MPM, as well as in thymic epithelial tumors (TETs). Here, we review the biological and clinical rationale for immune checkpoint inhibition in SCLC, MPM, and TETs and present preliminary clinical results with available antibodies. Immunotherapeutic perspectives for these malignancies in terms of novel agents currently under evaluation or anticipated in the near future are also discussed. Current immune checkpoint blockers targeting cytotoxic T-lymphocyte associated protein-4 and the programmed cell death-1/programmed death ligand-1 axis, administered alone or in combination and as multimodality treatment, are likely to be a valuable addition to the therapeutic array for managing SCLC and MPM; studies in TETs, which are currently in their infancy, are merited. Close attention to potential toxicities will be important to the success of such strategies in these settings.