Rational management approach to pure red cell aplasia

Efficacy and influencing factors of immunosuppressive therapy for pure red cell aplasia: meta-analysis and systematic review

Acquired pure red cell aplasia (aPRCA) is a rare hematological syndrome characterized by anemia and a significant reduction in erythroid progenitor cells. Immunosuppressive therapy (IST), including Corticosteroids (CS), Cyclosporine (CsA), and cyclophosphamide (CYC), is the primary treatment. However, variations in clinical efficacy and limited comparative studies have created uncertainty in therapeutic choices. This study aims to evaluate the efficacy of IST and the factors influencing treatment outcomes. A systematic search was conducted using PubMed, Embase, Cochrane Library, and Web of Science. Two researchers independently screened studies and extracted data. The quality of studies was assessed using the MINORS scale. Meta-analysis was performed using STATA/MP16, and effect size (ES) was calculated using fixed- or random-effects models based on heterogeneity. A total of 33 studies involving 1,193 patients were included. The overall efficacy of IST was significant, with a pooled ES of 0.656 (95% CI: 0.600-0.710). CsA demonstrated the highest efficacy (ES = 0.699; 95% CI: 0.615-0.779), followed by CYC (ES = 0.592; 95% CI: 0.423-0.752) and CS (ES = 0.568; 95% CI: 0.457-0.676). Subgroup analyses revealed that factors such as etiology, combination therapies, first- vs. second-line treatment, and genetic characteristics significantly influenced outcomes. Notably, the response to IST was higher in primary aPRCA (ES = 0.667; 95% CI: 0.598-0.733) compared to LGLL-associated (ES = 0.515; 95% CI: 0.393-0.637) and thymoma-associated (ES = 0.690; 95% CI: 0.492-0.864) aPRCA. The combination of CS and CsA yielded superior efficacy (ES = 0.761; 95% CI: 0.658-0.853) compared to combination of CS and CsA and monotherapy. First-line treatment demonstrated better efficacy than second-line treatment (ES = 0.659; 95% CI: 0.596-0.720) vs. (ES = 0.452; 95% CI: 0.199-0.715). The important finding was that (ES = 0.861; 95% CI: 0.595-1.000) in the STAT3 mutation (+) group and (ES = 0.375; 95% CI: 0.034-0.801) in the STAT3 mutation (-) group. IST demonstrates overall efficacy in aPRCA, with variations influenced by etiology, drug combinations, and genetic mutations such as STAT3. These findings highlight the need for personalized treatment strategies and further research to validate and optimize IST efficacy.

Thalidomide-based regimen shows promising efficacy in large granular lymphocytic leukemia: a multicenter phase II study

Large granular lymphocytic leukemia (LGLL) is characterized by the clonal proliferation of cytotoxic T lymphocytes or NK cells. Standard first-line immunosuppressive treatments have limitations, achieving complete remission (CR) rates of up to 50%. Immune system dysregulation is implicated in LGLL. Promising results for thalidomide, an immunomodulatory drug, combined with prednisone and methotrexate (TPM), were observed in our pilot study. This multicenter study evaluated the efficacy and safety of a thalidomide, prednisone, and methotrexate (TPM) regimen in 52 symptomatic, methotrexate- and thalidomide-naive LGLL patients from June 2020 to August 2022. Thalidomide (100 mg daily for up to 24 months), prednisone (0.5-1.0 mg/kg every other day, tapered after 3 months), and methotrexate (10 mg/m2 weekly for up to 12 months) were administered. The primary objective was to determine the CR rate. The median follow-up duration was 29.0 months (range: 4.0-42.0). Forty-seven patients (90.4%) achieved hematological and symptomatic responses. Thirty-nine patients (75.0%) achieved CR. The median time to response was 3.0 months (range: 3.0-9.0). The median progression-free survival was 40.0 months (95% confidence interval (CI): 38.0-42.0), and the median duration of response was 39.0 months (95% CI: 36.1-41.9). The most common adverse event was peripheral neuropathy (24.1%), most of which (84.6%) were grades 1-2. Four patients experienced grade ≥3 adverse events. In conclusion, the TPM regimen was an effective and safe treatment for symptomatic LGLL patients, with a particularly high CR rate. This trial was registered at www.clinicaltrials.gov (#NCT04453345).

Mutational heterogeneities in STAT3 and clonal hematopoiesis-related genes in acquired pure red cell aplasia

Dysregulation of T cell-mediated immunity is considered a major pathophysiological mechanism in acquired pure red cell aplasia (PRCA), including idiopathic PRCA, large granular lymphocytic leukemia-associated PRCA, and thymoma-associated PRCA. Although STAT3 mutations are frequently detected in PRCA patients, the roles of other mutational profiles and their impact on clinical characteristics remain unclear. In this study, whole-exome sequencing and targeted sequencing using a custom-designed panel were performed on 53 PRCA patients. The most frequently mutated genes were STAT3 (36%), PCLO (9%), TET2 (9%), NEB (6%), DNMT3A (6%), and POT1 (6%). Based on genetic profiles, patients were classified into three groups: those with STAT3 variants (group S), those without STAT3 variants but with variants in clonal hematopoiesis (CH)-related genes (group C), and those without variants in either STAT3 or CH-related genes (group O). Patients in group O had a higher median age compared to group S, while group S exhibited milder anemia severity than group C. Additionally, POT1 variants were associated with the idiopathic subtype of PRCA in females, often co-occurring with STAT3 variants. Variants in CH-related genes and other genes, including STAT3 and POT1, may play crucial roles in the pathophysiology of PRCA.

Myasthenia gravis complicated by pure red cell aplasia with clonal large granular lymphocytosis in the absence of thymoma: a rare case report and literature review

In 2013, a young woman during her early pregnancy was repeatedly hospitalized due to respiratory and swallowing difficulties. The pregnancy was terminated due to recurrent severe lung infections. She was later diagnosed with myasthenia gravis (MG) based on positive acetylcholine receptor antibodies. Her muscle weakness was subsequently well-controlled with pyridostigmine bromide, azathioprine, and prednisone. Notably, in the seventh year after her MG diagnosis (2021), the patient developed severe anemia (hemoglobin: 44 g/L). Bone marrow analysis revealed a rare combination of pure red cell aplasia (PRCA) with clonal expansion of large granular cells. Further examinations excluded thymoma. Considering the possibility of drug-induced PRCA, azathioprine was replaced with tacrolimus. Remarkably, the anemia resolved within 1 month, and her MG remained well-controlled. It is well-established that abnormal thymic hyperplasia within thymomas can alter the distribution and function of peripheral T lymphocytes, leading to the development of autoimmune diseases such as MG and PRCA. In this unique case without thymoma, we discussed the mechanisms and associations of PRCA with MG, medication, and clonal large granular T cells. This unique case highlights the unprecedented association of MG and PRCA without thymoma, underscoring the complexity of the disease spectrum. The patient's subsequent successful delivery in June 2023 adds another dimension to the multifaceted clinical course, warranting attention and exploration into potential connections between these conditions.

Overview of preclinical and phase II clinical studies on Pegmolesatide's long-term erythropoiesis stimulating effect via EPOR-mediated signal transduction

INTRODUCTION

Anemia is a prevalent complication of chronic kidney disease (CKD), primarily due to insufficient erythropoietin (EPO). Pegmolesatide (by Hansoh Pharma) is currently the only marketed long-acting EPO mimetic peptide (EMP) for the treatment of anemia in both dialysis and non-dialysis CKD patients. This paper aimed to explore the long-acting erythropoiesis stimulating molecular mechanism of Pegmolesatide.

METHODS

In vitro assays were utilized to assess Pegmolesatide erythropoietin receptor (EPOR) affinity, competitive binding, cell proliferation/survival, apoptosis, cell surface receptor expression, and signal transduction. Pharmacokinetics (PK) and Pharmacodynamics (PD) parameters were evaluated in BALB/c mice following single administration. Furthermore, two Phase II clinical trials in dialysis and non-dialysis chronic kidney disease (CKD) patients with anemia, respectively CTR20140533 and CTR20140539, assessed PK-PD and safety following repeated administration.

RESULTS

In vitro Pegmolesatide demonstrated enhanced binding stability and prolonged residency at EPOR, surpassing erythropoiesis-stimulating agents (ESAs) rHuEPO and Darbepoetin. This sustained EPOR binding facilitated heightened endogenous EPOR expression post-drug withdrawal, maintaining downstream signal transduction pathways (JAK2/STAT5, ERK1/2 MAPK) for erythropoiesis. Pegmolesatide promoted UT-7 cell proliferation & survival and suppressed apoptosis. Following a single 0.08 mg/kg dose of Pegmolesatide in BALB/c mice, reticulocyte count, red blood cells, hemoglobin, and hematocrit persisted at elevated levels 4-6 days after administration. In the two clinical Phase II studies dose-dependent increases in hemoglobin and prolonged response duration were independently observed. Pegmolesatide showed significant PK-PD dual prolongation effects and was well tolerated. Adverse events were mild and manageable, with no reports of severe anaphylaxis.

DISCUSSION

Preclinical and clinical evidence signifies that Pegmolesatide is a unique, potent PEGylated EPO-memetic peptide (EMP) with a prolonged PD efficacy and PK half-life and a good safety-tolerability profile. To elucidate further, future studies will address the endocytosis, intracellular degradation, and ligand release of EPOR subsequent to Pegmolesatide binding, thereby supplementing our understanding of the molecular mechanism at play.

TRIAL REGISTRATION

Phase IIa clinical study of Pegmolesatide on renal anemia, CTR20140533. Initial Public Notice 14 Jan 2015, http://www.chinadrugtrials.org.cn/clinicaltrials.searchlistdetail.dhtml . Phase II clinical study of Pegmolesatide on renal anemia, CTR20140539. Initial Public Notice 26 Jan 2015, http://www.chinadrugtrials.org.cn/clinicaltrials.searchlistdetail.dhtml .

Molecular landscape of CD8+ T cells in pure red cell aplasia

The aberrant function of lymphocytes is considered a significant contributing factor to pure red cell aplasia (PRCA), but the precise mechanism by which T lymphocytes induce erythroid development stagnation remains unclear. In our study, the CD8+ T lymphocytes were isolated from bone marrow aspirates of acquired PRCA patients and healthy controls. RNA sequencing (RNA-Seq) was performed to analyze gene expression profiles. Additionally, the expression levels of key molecules and transcription factors were assessed at the transcription and protein levels. The RNA-Seq analysis revealed a significant upregulation of genes associated with the PI3K/AKT/mTOR pathway in CD8+ T lymphocytes from patients with PRCA, compared to healthy controls. The mRNA expression of AKT, mTOR and key transcription factors T-bet were significantly upregulated in CD8+ T cells from patients with PRCA. Treatment with rapamycin, an mTOR inhibitor, attenuated the activation of CD8+ T lymphocytes in PRCA patients. Our findings demonstrate the activation of the PI3K/AKT/mTOR signaling pathway in CD8+ T lymphocytes of PRCA patients, suggesting its involvement in PRCA pathogenesis. Targeting this pathway may offer a potential therapeutic strategy for PRCA characterized by CD8+ T cell dysregulation.

Spectrum of Pure Red Cell Aplasia in a Tertiary Care Hospital in Northeast India

Background Pure red cell aplasia (PRCA) is an uncommon disorder characterized by severe normocytic normochromic anemia, reticulocytopenia, and an absence of erythroblasts from otherwise normal bone marrow. PRCA can present as either a congenital disorder or an acquired syndrome. Methodology A total of six cases of PRCA diagnosed in a tertiary care hospital from January 2016 to December 2019 were retrospectively studied. The diagnosis of PRCA was made based on bone marrow examinations showing erythroblastopenia with essentially normal myelopoiesis and megakaryopoiesis. Results Of the six patients, one was identified as having congenital PRCA, three were classified as having primary acquired PRCA, and two were diagnosed with secondary acquired PRCA. The congenital case was an infant diagnosed with Diamond-Blackfan anemia (DBA). There were three cases of primary acquired PRCA. One was idiopathic, as no specific cause could be identified. The other primary acquired case had autoimmune hemolytic anemia (AIHA); however, no underlying cause for peripheral hemolysis or secondary causes of marrow suppression could be identified. The third primary case was myelodysplastic PRCA. The causes of secondary acquired PRCA included systemic lupus erythematosus (SLE) and thymoma. Conclusion The present study demonstrates that the causes and outcomes of PRCA are varied; however, they are similar to those observed in other similar series.

Isatuximab for Delayed Red Cell Engraftment after Allogeneic Hematopoietic Cell Transplantation

Isatuximab is an IgG1κ-derived monoclonal antibody against CD38 approved for the treatment of adult patients with multiple myeloma. Here we describe the successful treatment of a therapy-refractory pure red cell aplasia case following ABO-mismatched allogeneic stem cell transplantation with isatuximab. Our patient was a 75-year-old female with acute myeloid leukemia who received an HLA-B antigen mismatched, unrelated peripheral blood stem cell transplant with a major ABO incompatibility (blood group A+ in the donor and blood group O+ in the recipient). The patient developed persistent red cell aplasia and anti-A antibodies for more than 500 days from transplant. She received therapy with rituximab, bortezomib, prednisone, and darbepoetin alfa with partial to no response. After repeated insurance denials for daratumumab, isatuximab was obtained from the manufacturer through their CareASSIST program. Following the completion of 2 cycles of isatuximab (8 doses), significant and sustained red cell recovery was observed.

Refractory pure red cell aplasia associated with T-cell large granular lymphocyte leukemia treated by ruxolitinib

Acquired pure red cell aplasia (PRCA) is a rare syndrome characterized by normocytic normochromic anemia with severe reticulocytopenia and absence of erythroid precursors in the bone marrow. For refractory PRCA patients, the low response rate and high toxicity of alternative therapies pose a great challenge. T-cell large granular lymphocyte (T-LGL) leukemia is one of the most common conditions in secondary PRCA and also the most difficult form to manage with an inferior treatment response to other secondary PRCA forms. T-LGL leukemia exhibits sustained activation of the intracellular JAK-STAT signaling pathway. We herein report a case of PRCA associated with T-LGL leukemia that had been refractory to multiple lines of therapies and was successfully treated by ruxolitinib. The patient achieved complete remission and tolerated ruxolitinib well without occurrence of neutropenia or thrombocytopenia. This preliminary finding favors ruxolitinib as a potential salvage therapy for refractory PRCA associated with T-LGL leukemia.

A nomogram model for predicting the efficacy of cyclosporine in patients with pure red cell aplasia

Pure red cell aplasia (PRCA) is a rare bone marrow disorder characterized by a severe reduction or absence of erythroid precursor cells, without affecting granulocytes and megakaryocytes. Immunosuppressive therapies, particularly cyclosporine, have demonstrated efficacy as a primary treatment. This study aims to develop a predictive model for assessing the efficacy of cyclosporine in acquired PRCA (aPRCA). This retrospective study encompasses newly treated aPRCA patients at the General Hospital of Tianjin Medical University. Diagnosis criteria include severe anemia, and absolute reticulocyte count below 10 × 109/L, with normal white blood cell and platelet counts, and a severe reduction in bone marrow erythroblasts. Cyclosporine therapy was administered, with dose adjustments based on blood concentration. Response to cyclosporine was evaluated according to established criteria. Statistical analysis involved logistic multi-factor regression, generating a predictive model. The study included 112 aPRCA patients with a median age of 63.5 years. Patients presented with severe anemia (median Hb, 56 g/L) and reduced reticulocyte levels. Eighty-six patients had no bone marrow nucleated erythroblasts. Primary PRCA accounted for 62 cases (55.4%), and secondary PRCA accounted for 50 cases (44.6%). Univariate analysis revealed that ferritin, platelet to lymphocyte ratio (PLR), and CD4/CD8 ratio influenced treatment response. Multivariate analysis further supported the predictive value of these factors. A prediction model was constructed using ferritin, PLR, and CD4/CD8 ratio, demonstrating high sensitivity and specificity. The ferritin, PLR, and CD4/CD8-based nomogram showed good predictive ability for aPRCA response to cyclosporine. This model has potential clinical value for individualized diagnosis and treatment of aPRCA patients.

Niraparib-induced pure red cell aplasia

INTRODUCTION

Niraparib, a strong poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitor, contributed significantly to progression-free survival as a maintenance therapy in the platinum-sensitive period in both first-line and recurrent ovarian cancer, regardless of the BRCA mutation. Grade 3-4 anemia, which has a manageable side effect profile, especially hematological, is seen in almost 1 out of every 4 patients. To the best of our knowledge, there has been no reported case of pure red cell aplasia (PRCA) induced by niraparib treatment.

CASE REPORT

A 65-year-old woman diagnosed with stage 3 serous carcinoma of the tuba received niraparib front-line maintenance treatment had grade 4 anemia after 3 months of niraparib treatment. She underwent bone marrow aspiration and biopsy because of refractory anemia, which needs red blood cell (RBC) transfusions despite interruption of treatment.

MANAGEMENT AND OUTCOME

The patient was treated with 1 mg/kg methyl prednisolone, after histopathological assessment was consistent with PRCA. The hemoglobin count returned to the normal range with steroid treatment.

DISCUSSION

In daily practice, it should be kept in mind that in the case of refractory anemia induced by niraparib, the underlying cause might be PRCA and can be improved with steroid administration.

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: The second hundred years

Pure red cell aplasia (PRCA) is a rare hematologic syndrome, characterized by an isolated normocytic anemia with severe reticulocytopenia, and defined by absence or near absence of erythroid precursors in the bone marrow. First described in 1922, PRCA may be a primary autoimmune or clonal myeloid or lymphoid disorder, but may also be secondary to other disorders of immune dysregulation/autoimmunity, to infections, to neoplasms, or to drugs. Insights from the study of PRCA have helped illuminate the understanding of the regulation of erythropoiesis. This review summarizes the classification, diagnostic, and therapeutic approach to PRCA as it begins its second century, with a particular focus on opportunities and challenges provided by new developments in the role of T-cells and T-cell regulatory mutations; the role of clonal hematopoiesis; and new developments in therapy for refractory PRCA and PRCA associated with ABO incompatible stem cell transplantation.

Distinct mutational pattern of T-cell large granular lymphocyte leukemia combined with pure red cell aplasia: low mutational burden of STAT3

T-cell large granular lymphocyte leukemia (T-LGL) is often accompanied by pure red cell aplasia (PRCA). A high depth of next generation sequencing (NGS) was used for detection of the mutational profiles in T-LGL alone (n = 25) and T-LGL combined with PRCA (n = 16). Beside STAT3 mutation (41.5%), the frequently mutated genes included KMT2D (17.1%), TERT (12.2%), SUZ12 (9.8%), BCOR (7.3%), DNMT3A (7.3%), and RUNX1 (7.3%). Mutations of the TERT promoter showed a good response to treatment. 3 of 41 (7.3%) T-LGL patients with diverse gene mutations were revealed as T-LGL combined with myelodysplastic syndrome (MDS) after review of bone marrow slide. T-LGL combined with PRCA showed unique features (low VAF level of STAT3 mutation, low lymphocyte count, old age). Low ANC was detected in a STAT3 mutant with a low level of VAF, suggesting that even the low mutational burden of STAT3 is sufficient for reduction of ANC. In retrospective analysis of 591 patients without T-LGL, one MDS patient with STAT3 mutation was revealed to have subclinical T-LGL. T-LGL combined with PRCA may be classified as unique subtype of T-LGL. High depth NGS can enable sensitive detection of concomitant MDS in T-LGL. Mutation of the TERT promoter may indicate good response to treatment of T-LGL, thus, its addition to an NGS panel may be recommended.

High TOX expression on CD8+ T cells in pure red cell aplasia

Thymocyte selection-associated high-mobility group box protein (TOX) is an important molecule regulating the development and exhaustion of T lymphocytes. Our aim is to investigate the role of TOX in the immune pathogenesis of pure red cell aplasia (PRCA). TOX expression of CD8⁺ lymphocytes from the peripheral blood of patients with PRCA was detected by flow cytometry. Additionally, the expression of immune checkpoint molecules PD1 and LAG3 and cytotoxic molecules perforin and granzyme B of CD8⁺ lymphocytes was measured. The quantity of CD4⁺CD25⁺CD127^low T cells was analyzed. TOX expression on CD8⁺ T lymphocytes in PRCA patients was significantly increased (40.73 [Formula: see text] 16.03 vs. 28.38 [Formula: see text] 12.20). The expression levels of PD1 and LAG3 on CD8⁺ T lymphocytes in PCRA patients were significantly higher than those in the control group (34.18 [Formula: see text] 13.26 vs. 21.76 [Formula: see text] 9.22 and 14.17 [Formula: see text] 13.74 vs. 7.24 [Formula: see text] 5.44, respectively). The levels of perforin and granzyme in CD8⁺ T lymphocytes of PRCA patients were 48.60 [Formula: see text] 19.02 and 46.66 [Formula: see text] 25.49, respectively, which were significantly higher than those of the control group (31.46 [Formula: see text] 7.82 and 16.17 [Formula: see text] 4.84, respectively). The number of CD4⁺CD25⁺CD127^low Treg cells in PRCA patients was significantly decreased (4.30 [Formula: see text] 1.27 vs. 1.75 [Formula: see text] 1.22). In PRCA patients, CD8⁺ T cells were activated and exhibited overexpression of TOX, PD1, LAG3, perforin, and granzyme B, while regulatory T cells decreased. These findings suggest that T cell abnormality plays a critical role in the pathogenesis of PRCA.

[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.

Hepatitis C Infection Associated with Acquired Pure Red Cell Aplasia

Acquired pure red cell aplasia is a rare bone marrow failure disorder characterized by many underlying etiologies. The hallmark bone marrow feature is the near absence of erythroid precursors that otherwise exhibit normal cellularity, which has been attributed to both immune- and cellular-mediated mechanisms. Besides being merely speculative and considering the rarity of the disorder, the description of acquired pure red cell aplasia clinical associations represents a unique occasion to improve our current clinical knowledge of the disease, reveal clues on its pathogenesis, and guide therapeutic decisions. The varied clinical scenarios and common acquired pure red cell aplasia associated conditions (i.e., thymoma, T cell/NK-cell large granular lymphocyte leukemia, B cell dyscrasia) suggest a heterogeneity of pathogenic routes. Viral etiologies must always be considered and worked up in the initial assessment of newly diagnosed acquired pure red cell aplasia patients. In this report, we present two cases of hepatitis-C-related acquired pure red cell aplasia and successful use of anti-viral strategies in the achievement of a complete response.

Pure Red Cell Aplasia Encountered in a Tertiary Care Hematology Laboratory: A Series of Nine Distinctive Cases

Pure red cell aplasia (PRCA) is characterized by severe anemia with reticulocytopenia and bone marrow erythroblastopenia. The early erythroblasts are markedly decreased; however, in rare instances, they may be normal or raised in number. There are varied etiologies, namely congenital or acquired and primary or secondary. The congenital PRCA is known as “Diamond-Blackfan anemia.” Thymomas, autoimmune disease, lymphomas, infections, and drugs also may be familiar associates. However, the etiologies of PRCA are numerous, and many diseases/infections can be associated with PRCA. The diagnosis rests on clinical suspicion and appropriate laboratory workup. We evaluated nine cases of red cell aplasia, having severe anemia with reticulocytopenia. Nearly half of the cases showed adequate erythroid (> 5% of the differential count) but with a maturation arrest. The adequacy of the erythroid could confuse the hematologist and may even delay the diagnosis. Hence, it is empirical that PRCA could be considered a differential in every case of severe anemia with reticulocytopenia, even in the presence of adequate erythroid precursors in the bone marrow.

Adult pure red cell aplasia at Universitas Academic Hospital, Bloemfontein, South Africa: A 9-year review

Background. Pure red cell aplasia (PRCA) is characterised by severe normochromic, normocytic anaemia and partial or complete absence of reticulocytes from the peripheral blood. With bone marrow of normal cellularity, an almost complete absence of erythroblasts but preservation of other cell lines is observed. It may be congenital or acquired, with the latter presenting as a primary haematological disorder or secondary to various contributing factors. Management focuses on treatment of the underlying cause and supportive transfusions. Occasionally, immunosuppression or intravenous immunoglobulin (IVIG) is required.Objectives. To describe the clinical characteristics, treatment and outcomes of adult patients diagnosed with PRCA at Universitas Academic Hospital (UAH) in Bloemfontein, South Africa, from 2010 to 2018.Methods. A retrospective descriptive file review was performed. All adult patients diagnosed with PRCA and treated in the Division of Clinical Haematology at UAH during the study period were included. Variables recorded included demographic information, clinical details of the PRCA diagnosis, classification of the PRCA, HIV and parvovirus B19 test results, results of special investigations, medical and drug history, treatment and response to treatment.Results. Twenty-seven patients’ files were included, with a female predominance (n=22; 81.5%). The median age at diagnosis was 35 years (range 20 - 62). The median number of days from onset of symptoms to date of diagnosis was 61 days (range 27 - 114). Approximately half (n=13; 48.2%) of the patients presented with a haemoglobin concentration of 1 - 3 g/dL. Most patients (n=26; 96.3%) were infected with HIV, with 76.9% (n=20) having a suppressed viral load. Parvovirus B19 infection accounted for 44.4% of cases (n=12), and all these patients were HIV positive. Lamivudine was a probable cause of PRCA in 18.5% of cases, although the true causal relationship was uncertain. Corticosteroids and IVIG were first-line therapy in 44.4% (n=12) and 37.0% (n=10) of cases, respectively. Thirteen patients (48.2%) achieved a complete response and 7 (25.9%) a partial response, while 2 (7.4%) showed no response, with continued transfusion dependence.Conclusion. In this population, women were disproportionately affected by PRCA. HIV was the single most important cause of acquired PRCA, which was independent of virological control. Parvovirus B19 and drugs were also important causes of acquired PRCA and played a critical part in the evaluation and work-up of PRCA. Nearly half of the patients achieved a complete response to therapy, which was sustained over 24 months.

[Erythroblastopenia and primary myelofibrosis: a very rare association (a case report)]

The combination of erythroblastopenia and primary myelofibrosis is very rare. We here report the unusual case of a 76-year-old Moroccan patient followed up since 2018 for idiopathic erythroblastopenia, initially treated with corticotherapy and then with ciclosporin. Two years later, the patient reported bone pain with splenomegaly. Assessment including myelogram, bone marrow biopsy and molecular biology showed myelofibrosis. Etiological assessment of myelofibrosis was negative confirming its primitive nature. The patient received ruxolitinib with transfusion support. Patient´s outcome was favorable and marked by improvement of general condition, splenomegaly and transfusion rate. The association between erythroblastopenia and myeloproliferative disorder is exceptional and only a few cases have been reported in the literature.

Incidence of acquired pure red cell aplasia: a nationwide epidemiologic analysis with 2 registry databases in Japan

Acquired pure red cell aplasia (PRCA) is a rare syndrome characterized by anemia with reticulocytopenia and a marked reduction in erythroid precursors. Given its rarity, the true incidence is largely unknown, and epidemiological data representing the general population, with a description of the full spectrum of etiologies, are scarce. An epidemiological study on PRCA in Japan conducted 30 years ago estimated the annual incidence as 0.3 per million. To update the data and investigate the incidence and demographics of PRCA, we conducted a nationwide epidemiological study using the Japanese Society of Hematology (JSH) Hematologic Disease Registry, a hematologic disease registration database managed by the JSH and the Diagnosis Procedure Combination (DPC) study data available at a website of the Ministry of Health, Labor, and Welfare (MHLW) of Japan. A total of 1055 patients with newly diagnosed acquired PRCA were identified between 2012 and 2019, and the average annual incidence was calculated at 1.06 (95% confidence interval [CI], 0.83-1.28) per million. The median age was 73 (range, 18-99) years. The female-to-male ratio was 1.5:1, and the female predominance was most prominent in the child-bearing age group. Sixty-nine percent of acquired PRCA was idiopathic. The incidence of PRCA was approximately 20% of that of aplastic anemia (AA) during the same period. Approximately 0.98 patients per million per year (95% CI, 0.89-1.07) required hospitalization for the treatment of PRCA. These results are expected to contribute to the discussion of resource allocation for PRCA in the aging population in many countries, including Japan.

T cell clonal expansion and STAT3 mutations: a characteristic feature of acquired chronic T cell-mediated pure red cell aplasia

Acquired chronic pure red cell aplasia (PRCA) develops idiopathically or in association with other medical conditions, including T cell large granular lymphocytic leukemia (T-LGLL) and thymoma. T cell dysregulation is considered a cardinal pathogenesis of PRCA, but genetic-phenotypic associations in T cell abnormalities are largely unclear. We evaluated an extended cohort of 90 patients with acquired PRCA, including 26 with idiopathic, 36 with T-LGLL-associated and 15 with thymoma-associated PRCA, for their T cell immuno-phenotypes, clonalities and STAT3 mutations. TCR repertoire skewing of CD8⁺ T cells was detected in 37.5% of idiopathic, 66.7% of T-LGLL-associated and 25% of thymoma-associated PRCA patients, and restriction to Vβ1 was most prominent (41%). Clonalities of TCRβ or γ chain and STAT3 mutational status were statistically associated (P = 0.0398), and they were detected in all three subtypes. The overall response rate to cyclosporin A was 73.9%, without significant difference by subtypes nor STAT3 mutational status. The T cell dysregulations, such as TCR repertoire skewing with predominant Vβ1 usage, clonality and STAT3 mutations, were frequently found across the subtypes, and the close associations between them suggest that these T cell derangements reflect a common pathophysiological mechanism among these PRCA subtypes.

How I manage autoimmune cytopenias in patients with lymphoid cancer

Autoimmune conditions can occur in a temporary relationship with any malignant lymphoma. In many instances, treatment at diagnosis is not required, but symptomatic autoimmune conditions represent an indication for treatment, particularly in chronic lymphoproliferative diseases. Treatment is selected depending on the predominant condition: autoimmune disease (immunosuppression) or lymphoma (antilymphoma therapy). Steroids and anti-CD20 antibodies are effective against both conditions and may suppress the autoimmune complication for a prolonged period. The efficacy of B-cell receptor inhibitors has provided us with novel insights into the pathophysiology of antibody-producing B cells. Screening for underlying autoimmune conditions is part of the lymphoma workup, because other drugs, such as immunomodulators and checkpoint inhibitors, should be avoided or used with caution. In this article, we discuss diagnostic challenges and treatment approaches for different situations involving lymphomas and autoimmune cytopenias.

Sirolimus is effective for refractory/relapsed/intolerant acquired pure red cell aplasia: results of a prospective single-institutional trial

Some patients with acquired pure red cell aplasia (aPRCA) have no response or are intolerant to cyclosporine A. From April 2017 to August 2020, patients diagnosed with aPRCA at Peking Union Medical College Hospital who were refractory/recurrent/intolerant to at least 6 months of full-dose cyclosporin A (CsA) with/without steroids were recruited and treated with sirolimus for at least 6 months. Finally, a total of 64 patients were enrolled. The overall response rate and complete response rate after 3, 6 and 12 months of sirolimus were 60.9%, 84.4%, and 73.5% and 50.0%, 65.6%, and 66.0%, respectively. At a median of 14.5 (6-47) months of follow-up, 14.8% (8/54) of the patients relapsed. Apart from haemoglobin improvement, patients had decreased creatine levels and serum ferritin levels at the end of the follow-up compared with the baseline (169.3 μmol/L vs. 146.4 μmol/L, p = 0.041; 2121.5 ng/mL vs. 1018.3 ng/mL, p = 0.013). Adverse events were recorded in 19 patients, including infections and increase of creatine. Secondary aPRCA with stable underlying diseases had similar results as those with primary aPRCA. In summary, sirolimus is effective for patients with refractory/recurrent/intolerant aRPCA with a low recurrence rate and toxicities.

Isolated anemia in patients with large granular lymphocytic leukemia (LGLL)

Patients with large granular lymphocytic leukemia (LGLL) frequently present with neutropenia. When present, anemia is usually accompanied by neutropenia and/or thrombocytopenia and isolated anemia is uncommon. We evaluated a cohort of 244 LGLL patients spanning 15 years and herein report the clinicopathologic features of 34 (14%) with isolated anemia. The patients with isolated anemia showed a significantly male predominance (p = 0.001), a lower level of hemoglobulin (p < 0.0001) and higher MCV (p = 0.017) and were less likely to have rheumatoid arthritis (p = 0.023) compared to the remaining 210 patients. Of the 34 LGLL patients with isolated anemia, 13 (38%) presented with pure red cell aplasia (PRCA), markedly decreased reticulocyte count and erythroid precursors, and more transfusion-dependence when compared to non-PRCA patients. There was no other significant clinicopathologic difference between PRCA and non-PRCA patients. 32 patients were followed for a median duration of 51 months (6-199). 24 patients were treated (11/11 PRCA and 13/21 non-PRCA patients, p < 0.02). The overall response rate to first-line therapy was 83% [8/11 (72.7%) for PRCA, 12/13 (92.3%) for non-PRCA], including 14 showing complete response and 6 showing partial response with a median response duration of 48 months (12-129). Half of non-PRCA patients who were observed experienced progressive anemia. During follow-up, no patients developed neutropenia; however, 5/27 (18.5%) patients developed thrombocytopenia. No significant difference in overall survival was noted between PRCA and non-PRCA patients. In summary, this study demonstrates the unique features of LGLL with isolated anemia and underscores the importance of recognizing LGLL as a potential cause of isolated anemia, which may benefit from disease-specific treatment. LGLL patients with PRCA were more likely to require treatment but demonstrated similar clinicopathologic features, therapeutic responses, and overall survival compared to isolated anemia without PRCA, suggesting PRCA and non-PRCA of T-LGLL belong to a common disease spectrum.

Toward a Better Classification System for NK-LGL Disorders

Large granular lymphocytic leukemia is a rare lymphoproliferative disorder characterized by a clonal expansion of T-lineage lymphocyte or natural killer (NK) cells in 85 and 15% of cases respectively. T and NK large granular leukemia share common pathophysiology, clinical and biological presentation. The disease is characterized by cytopenia and a frequent association with autoimmune manifestations. Despite an indolent course allowing a watch and wait attitude in the majority of patients at diagnosis, two third of the patient will eventually need a treatment during the course of the disease. Unlike T lymphocyte, NK cells do not express T cell receptor making the proof of clonality difficult. Indeed, the distinction between clonal and reactive NK-cell expansion observed in several situations such as autoimmune diseases and viral infections is challenging. Advances in our understanding of the pathogenesis with the recent identification of recurrent mutations provide new tools to prove the clonality. In this review, we will discuss the pathophysiology of NK large granular leukemia, the recent advances in the diagnosis and therapeutic strategies.

Novel Adenosine Deaminase 2 (ADA2) Mutations Associated With Hematological Manifestations

Recent progress in laboratory techniques, particularly, identification of novel disease-causing genes, has led to the detection of different gene mutations that might be implicated in the pathogenesis of different hematological disorders like pure red cell aplasia (PRCA) and neutropenia. An autoinflammatory disorder known as deficiency of adenosine deaminase 2 (DADA2) has been recently noticed to present with variable hematologic abnormalities. We report 2 patients who presented with hematologic abnormalities in which 2 ADA2 gene mutations were detected. The first case is a 5-year-old girl who presented with severe PRCA and autoimmune hemolytic anemia without any other manifestation of DADA2 that resulted from a novel CECR1 c.714_738dup, p. (Ala247Glnfs*16) homozygous variant. The second case is a 10-year-old boy, known to have Hodgkin lymphoma and was under follow-up for 6 years; he presented with persistent neutropenia and was discovered to be homozygous for ADA2 c.1447_1451del, p. (Ser483Profs*5). In conclusion, we report two different novels ADA2 variants in two children; the first presented with PRCA and the second presented with persistent neutropenia. This report aims to raise the concerns regarding the use of genetic testing in different hematologic diseases with indefinite etiology, as it will lead to the best therapeutic strategies without the need for unnecessary interventions.

Anti Thymocyte Globulin-Based Treatment for Acquired Bone Marrow Failure in Adults

Idiopathic acquired aplastic anemia can be successfully treated with Anti Thymocyte Globulin (ATG)-based immune suppressive therapy and is therefore considered a T cell-mediated auto immune disease. Based on this finding, several other forms of idiopathic acquired bone marrow failure are treated with ATG as well. For this review, we extensively searched the present literature for evidence that ATG can lead to enduring remissions in different forms of acquired multi- or single-lineage bone marrow failure. We conclude that ATG-based therapy can lead to an enduring hematopoietic response and increased overall survival (OS) in patients with acquired aplastic aplasia. In patients with hypocellular myelodysplastic syndrome, ATG can lead to a hematological improvement without changing the OS. ATG seems less effective in acquired single-lineage failure diseases like Pure Red Cell Aplasia, Amegakaryocytic Thrombocytopenia and Pure White Cell Aplasia, suggesting a different pathogenesis in these bone marrow failure states compared to aplastic anemia. T cell depletion is hypothesized to play an important role in the beneficial effect of ATG but, as ATG is a mixture of polyclonal antibodies binding to different antigens, other anti-inflammatory or immunomodulatory effects could play a role as well.

Large Granular Lymphocytic Leukemia: From Immunopathogenesis to Treatment of Refractory Disease

Large Granular Lymphocyte Leukemia (LGLL) is a rare, chronic lymphoproliferative disorder of effector cytotoxic T-cells, and less frequently, natural killer (NK) cells. The disease is characterized by an indolent and often asymptomatic course. However, in roughly 50% of cases, treatment is required due to severe transfusion-dependent anemia, severe neutropenia, or moderate neutropenia with associated recurrent infections. LGLL represents an interesting disease process at the intersection of a physiological immune response, autoimmune disorder, and malignant (clonal) proliferation, resulting from the aberrant activation of cellular pathways promoting survival, proliferation, and evasion of apoptotic signaling. LGLL treatment primarily consists of immunosuppressive agents (methotrexate, cyclosporine, and cyclophosphamide), with a cumulative response rate of about 60% based on longitudinal expertise and retrospective studies. However, refractory cases can result in clinical scenarios characterized by transfusion-dependent anemia and severe neutropenia, which warrant further exploration of other potential targeted treatment modalities. Here, we summarize the current understanding of the immune-genomic profiles of LGLL, its pathogenesis, and current treatment options, and discuss potential novel therapeutic agents, particularly for refractory disease.

Distinguishing constitutional from acquired bone marrow failure in the hematology clinic

Distinguishing constitutional from immune bone marrow failure (BMF) has important clinical implications. However, the diagnosis is not always straightforward, and immune aplastic anemia, the commonest BMF, is a diagnosis of exclusion. In this review, we discuss a general approach to the evaluation of BMF, focusing on clinical presentations particular to immune and various constitutional disorders as well as the interpretation of bone marrow histology, flow cytometry, and karyotyping. Additionally, we examine the role of specialized testing in both immune and inherited BMF, and discuss genetic testing, both its role in patient evaluation and interpretation of results.

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immune checkpoint inhibitor-related adverse events

Immune checkpoint inhibitors (ICIs) are the standard of care for the treatment of several cancers. While these immunotherapies have improved patient outcomes in many clinical settings, they bring accompanying risks of toxicity, specifically immune-related adverse events (irAEs). There is a need for clear, effective guidelines for the management of irAEs during ICI treatment, motivating the Society for Immunotherapy of Cancer (SITC) to convene an expert panel to develop a clinical practice guideline. The panel discussed the recognition and management of single and combination ICI irAEs and ultimately developed evidence- and consensus-based recommendations to assist medical professionals in clinical decision-making and to improve outcomes for patients.

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.

Good treatment-free survival of monoclonal gammopathy of undetermined significance associated pure red cell aplasia after bortezomib plus dexamethasone

Pure red cell aplasia (PRCA) is a rare syndrome characterized by severe anemia and absence of erythroid precursors. PRCA associated to monoclonal gammopathy of undetermined significance (MGUS) is a scarce condition with less than five cases reported so far. There is no agreement on the treatment of MGUS associated PRCA and treatment- free survival (TFS) is an unmet clinical need. In this report, for the first time, we demonstrated two patients with MGUS associated PRCA obtained rapid remission and maintained TFS after accepting intensive short-term bortezomib plus dexamethasone. The first case was refractory to cyclosporine and prednisone, but achieved complete remission after ten doses of bortezomib. Moreover, he has kept TFS for 12 months. The other case initiated bortezomib plus dexamethasone as soon as making a definite diagnosis. She obtained complete remission after twelve doses of bortezomib and she has maintained a normal level of haemoglobin for 8 months.

How I manage acquired pure red cell aplasia in adults

Pure red cell aplasia (PRCA) is a rare hematological disorder with multiple etiologies. The multifaceted nature of this disease is emphasized by the variety of concomitant clinical features. Classic idiopathic presentation aside, prompt recognition of pathogenetic clues is important because of their diagnostic and therapeutic implications. As a consequence, treatment of PRCA is diverse and strictly dependent on the presented clinical scenario. Here, we propose a series of clinical vignettes that showcase instructive representative situations derived from our routine clinical practice. Using these illustrative clinical cases, we review the diagnostic workup needed for a precise diagnosis and the currently available therapeutic options, discussing their applications in regard to the various PRCA-associated conditions and individual patients' characteristics. Finally, we propose a treatment algorithm that may offer guidance for personalized therapeutic recommendations.

Treatment for pure red cell aplasia after major ABO-incompatible allogeneic stem cell transplantation: a multicentre study

Pure red cell aplasia (PRCA) following allogeneic haematopoietic stem cell transplantation (aHSCT) with major ABO incompatibility is responsible for transfusion dependent anaemia, impaired quality of life and iron overload. We conducted a retrospective study, over a 10-year period, which included all consecutive patients who received a major ABO mismatched aHSCT, to assess the impact of specific treatment on PRCA. We did not observe any PRCA in the 57 aHSCT issued from cord blood. Among the remaining 631 patients, cumulative incidence of PRCA was 10·5% [range 8·2-13.0]. The median duration of resolved PRCA was 171 days [IQR 116; 261]. Pre-transplant high isohaemagglutinins titre was associated with an increased risk of PRCA (P < 10^-4 ). PRCA did not affect overall survival (P = 0·95). Twenty-two patients (33·3%) received at least one specific treatment. The most commonly used treatments were rituximab (17 patients) and donor lymphocyte infusion (DLI; seven patients). Regarding PRCA resolution, we did not observe a significant difference between treated or untreated subjects (HR = 0·93, 95% confidence interval (CI) 0·48- 1·80; P = 0·82). Similar results were observed with erythropoietin treatment (22 patients, HR = 0·86 95% CI: [0·47-1·57] P = 0·62). Our data do not support the use of erythropoietin, rituximab or DLI for the treatment of PRCA.

A Case of Systemic Lupus Erythematosus Presenting as Pure Red Cell Aplasia

Pure red cell aplasia (PRCA) is an uncommon condition, which is rarely associated with Systemic Lupus Erythematosus (SLE). Prompt identification and management of the underlying SLE results in correction of anemia. We report the case of a young female who presented due to severe anemia since the last two years. The cause of her anemia on initial investigations was not elicited in these two years, during which response to hematinics was poor and she remained transfusion dependent. Bone marrow biopsy showed PRCA after which autoimmune workup revealed SLE. Subsequently, treatment of SLE with steroids led to normalization of hemoglobin levels within a follow-up period of three months.

Clonal hematopoiesis in adult pure red cell aplasia

Idiopathic pure red cell aplasia (PRCA) and secondary PRCA associated with thymoma and large granular lymphocyte leukemia are generally considered to be immune-mediated. The PRCA2004/2006 study showed that poor responses to immunosuppression and anemia relapse were associated with death. PRCA may represent the prodrome to MDS. Thus, clonal hematopoiesis may be responsible for treatment failure. We investigated gene mutations in myeloid neoplasm-associated genes in acquired PRCA. We identified 21 mutations affecting amino acid sequences in 11 of the 38 adult PRCA patients (28.9%) using stringent filtering of the error-prone sequences and SNPs. Four PRCA patients showed 7 driver mutations in TET2, DNMT3A and KDM6A, and 2 PRCA patients carried multiple mutations in TET2. Five PRCA patients had mutations with high VAFs exceeding 0.3. These results suggest that clonal hematopoiesis by stem/progenitor cells might be related to the pathophysiology of chronic PRCA in certain adult patients.

Autoimmune disorders and paraneoplastic syndromes in thymoma

Thymomas are counted among the rare tumour entities which are associated with autoimmune disorders (AIDs) and paraneoplastic syndromes (PNS) far more often than other malignancies. Through its complex immunological function in the context of the selection and maturation of T cells, the thymus is at the same time highly susceptible to disruptive factors caused by the development and growth of thymic tumours. These T cells, which are thought to develop to competent immune cells in the thymus, can instead adopt autoreactive behaviour due to the uncontrolled interplay of thymomas and become the trigger for AID or PNS affecting numerous organs and tissues within the human body. While myasthenia gravis is the most prevalent PNS in thymoma, numerous others have been described, be they related to neurological, cardiovascular, gastrointestinal, haematological, dermatological, endocrine or systemic disorders. This review article sheds light on the pathophysiology, epidemiology, specific clinical features and therapeutic options of the various forms as well as courses and outcomes of AID/PNS in association with thymomas. Whenever suitable and backed by the limited available evidence, the perspectives from both the thymoma and the affected organ/tissue will be highlighted. Specific issues addressed are the prognostic significance of thymectomy on myasthenia gravis and other thymoma-associated AID/PND and further the impact and safety of immunotherapies on AID and PND relating to thymomas.

Acquired Pure Red Cell Aplasia Associated with Chronic Myelomonocytic Leukemia: Too Many of One, Not Enough of the Other

There is a growing body of literature outlining the association between certain hematological malignancies, such as chronic myelomonocytic leukemia (CMML), and systemic autoimmune diseases. Diagnosis and management can be difficult, particularly when autoimmune phenomena overlap with features of the underlying illness. This is especially the case in patients who develop immune-mediated cytopenias in the context of underlying bone marrow disease. CMML associated with immune thrombocytopenia and hemolytic anemia has been reported a number of times in the literature; however, there are only scattered case reports describing CMML associated with acquired pure red cell aplasia. Here, we describe the diagnostic and management approach to a patient who developed both diseases.

[Clinical analysis of 67 cases of pure red cell aplastic anemia]

Objective: To investigate secondary factors, laboratory features, treatment options, and prognosis of pure red cell aplastic anemia (PRCA) . Methods: This was a multicenter retrospective clinical study. Patients aged above 18 years newly diagnosed with PRCA between June 1, 2010, and June 1, 2019, were recruited as the main study object. A comparative analysis of remission rate and overall survival rate was made according to different treatment schemes adopted by patients and different drug reduction rates. Results: A total of 67 patients with PRCA were included in this study and the secondary PRCA group accounted for 44.8% (30/67) . The most common secondary factors were thymoma (n=10) and T-cell large lymphocytic leukemia (T-LGLL) (n=6) . The overall response rate of PRCA was 85.7% and the 3-year overall survival rate of PRCA was (74.3±7.5) %. The remission rate of cyclosporine A alone was slightly higher than that of oral glucocorticoid alone or combined with glucocorticoid[90.0% (36/40) vs 75.0% (12/16) , P=0.147]. After patients applied with cyclosporine A treatment reached CR/PR and remained stable for 3-6 months, the dose of cyclosporine A was reduced by 25 mg each time. The cyclosporine A reduction interval of a 25 mg/d reduction in more than 1 month significantly prolonged the median disease-free survival compared with a 25 mg/d reduction in less than 1 month [not reached vs 15 (95% CI 7-23) months, P<0.001]. There were 62.5% (10/16) of patients who responded to the initial or incremental treatment regimen after relapse. Conclusion: PRCA has features of various secondary factors, high overall survival rate, and high remission rate. Treatment with cyclosporine A alone is preferred, and cyclosporine A should be slowly tapered to reduce the risk of later relapse after it takes effect and patients reach a steady state.

Immunosuppressive therapy for elderly-acquired pure red cell aplasia: cyclosporine A may be more effective

This current study retrospectively analyzed the clinical characteristics of 69 adult patients with acquired pure red cell aplasia (PRCA) including 40 elderly and 29 non-elderly patients from September 2009 to June 2019. The remission induction therapy regimens included cyclosporine A (CsA), corticosteroids (CS), or other immunosuppressive agents. The overall response rate was 55% (22/40) in the elderly group compared with 75.9% (22/29) in non-elderly patients (P = 0.075). In elderly patients, the best remission was achieved in the group treated with CsA than those treated with CS or other immunosuppressive agents (83.3% vs 26.7% vs 42.9%%, P = 0.004). However, outcomes of remission were similar among different treatment groups (P = 0.458) in non-elderly patients. CS induced a higher response rate in the non-elderly than that in the elderly (88.9% vs 26.7%, P = 0.009). By univariate and multivariate analysis, the clinical efficacy of elderly patients with acquired PRCA was closely associated with an induction regimen of CsA (P = 0.009; P = 0.017). In conclusion, CsA might produce higher response rate than CS and other drugs in elderly patients with acquired PRCA.