Transient erythroblastopenia of childhood after COVID-19 infection: a case report.

BACKGROUND: Transient erythroblastopenia of childhood (TEC) is an acquired, self-limited pure red cell aplasia that usually occurs in children 4 years old and younger. This clinical condition has been priorly described to be linked to numerous viral and immunologic mechanisms. COVID-19, caused by the coronavirus SARS-CoV-2, was initially discovered in China in December 2019. The disease quickly spread worldwide, resulting in pandemic. CASE PRESENTATION: This manuscript reports a new clinically relevant condition associated to COVID-19, describing a child with clinical and biochemical signs of Pure Red Blood cells aplasia and complete absence of erythroblasts at the bone marrow needle aspiration with signs of erythrophagocytosis, resembling morphological signs such as in hemophagocytic lymphohistiocytosis (HLH), temporally associated to SARS-CoV-2 infection. CONCLUSION: This report highlights a newly described continuum laboratory and clinical spectrum of immune/hematological dysregulations secondary to SARS-CoV-2. SARS-CoV-2 infection-linked TEC has never been described in literature, but, according to our findings, should be considered in all the patients with transient erythroblastopenia without congenital red blood cell abnormalities and serology negative for major infections associated with TEC. This condition must be considered in the same spectrum of MIS-C and the inter-links among the two clinical manifestations, as well as a potential interdependence among them, should be considered in the future.

Neuromyelitis Optica spectrum disorder complicated with pure red cell aplasia: a case report.

BACKGROUND: Pure red cell aplasia (PRCA) in neuromyelitis optica spectrum disorder (NMOSD) has not been reported before. This study presents a patient with NMOSD who developed PRCA. CASE PRESENTATION: A 54-year-old female was admitted in January 2023 for dysuria and progressive numbness and weakness of lower limbs. She had difficulty standing and walking in a straight line. Both lower limbs were positive for the Babinski and Chaddock signs. MRI showed abnormal signals in the spinal cord. Aquaporin-4-IgG (AQP-4-IgG) was positive (1:320), and NMOSD was confirmed. Intravenous immunoglobulin and methylprednisolone were given, and the symptoms improved. She received maintenance treatment with methylprednisolone tablets, and the dosage was gradually reduced. She was readmitted for fatigue, palpitations, and shortness of breath in May 2023. Bone marrow aspiration and biopsy showed elevated erythroid precursors and erythroid hypoplasia, with normal megakaryocytes and myeloid precursors. Chest CT showed no mediastinal lymph node enlargement or thymoma. PRCA secondary to NMOSD was diagnosed. Recombinant human erythropoietin was given. Her condition improved after 1.5 months, as indicated by blood cell count and imaging. CONCLUSIONS: This case suggests that PRCA can be secondary to NMOSD. A comprehensive immune function and bone marrow evaluation might be necessary if abnormal blood cells are found while managing NMOSD.

Pure red cell aplasia secondary to erythropoietin therapy.

We report a case series of two patients with chronic kidney disease (CKD) who developed erythropoietin-induced pure red cell aplasia following a change in erythropoietin preparation. Both patients responded well to immunosuppressive treatments, but unfortunately developed severe infections as a result of being immunosuppressed.

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.

STK10 mutations block erythropoiesis in acquired pure red cell aplasia via impairing ribosome biogenesis.

Acquired pure red cell aplasia (PRCA) is anemia associated with the absence of erythroblasts and is characterized by persistent and easy recurrence. However, the underlying mechanisms of acquired PRCA remain obscure, and the role of gene mutations in the pathogenesis of acquired PRCA is not fully characterized. In the present study, we detected thirty newly diagnosed patients with acquired PRCA using whole exome sequencing, and a potential role for STK10 in acquired PRCA was uncovered. The mRNA levels of STK10 in three patients with STK10 mutations were decreased. These three patients had a poor response to immunosuppressive therapy and two died in the follow-up period. Here we report that knockdown of STK10 inhibits erythroid differentiation and promotes apoptosis of K562 cells. We show that knockdown of STK10 resulted in inhibition of ribosome biogenesis and reduced ribosome levels in K562 cells. We also show that the p53 signaling pathway is activated by knockdown of STK10. Our results imply that ribosome biogenesis downregulation together with pathological p53 activation prevents normal erythropoiesis. Our study uncovers a new pathophysiological mechanism leading to acquired PRCA driven by STK10 mutations.

Pure Red Cell Aplasia and Chromosomal Abnormality in a Patient With Lung Adenocarcinoma Receiving Immune Checkpoint Inhibitors: A Case Report.

BACKGROUND/AIM: Immune checkpoint inhibitors can induce immune-related adverse events in various organs, thus careful observation is required. CASE REPORT: A 69-year-old man was diagnosed with advanced lung adenocarcinoma and treated with combined therapy of carboplatin plus pemetrexed plus pembrolizumab. After two cycles of treatment, anemia was noted. Myelosuppression due to cytotoxic anticancer agents was suspected and the cytotoxic agents were discontinued, followed by three courses of pembrolizumab monotherapy. However, the anemia persisted, requiring red blood cell transfusions. A bone marrow biopsy revealed erythroblast hypoplasia and chromosomal abnormalities, resulting in a diagnosis of pure red cell aplasia. These adverse events were considered immune-related because of the treatment history with an immune checkpoint inhibitor, and 60 mg/day (1 mg/kg/day) of prednisolone was initiated. Anemia improved, and it did not recur during the tapering of prednisolone. CONCLUSION: Immune-related pure red cell aplasia should be considered for patients presenting anemia during treatment with immune checkpoint inhibitors.

Gilteritinib combined with venetoclax and azacitidine for relapsed acute myeloid leukemia cocurrent with pure red cell aplasia after allogeneic hematopoietic stem cell transplantation: a case report.

Pure red cell aplasia (PRCA) is a rare bone marrow (BM) disorder characterized by ineffective erythropoiesis, reduced reticulocyte count, normocytic anemia, and the absence of erythroid precursors. Here, we present a rare instance of PRCA occurring after ABO-matched allo-HSCT in a refractory/relapsed acute myeloid leukemia (R/R AML) patient. In this case, the patient received a combination treatment of Gilteritinib, Venetoclax, and Azacitidine. Remarkably, this treatment not only reduced myeloblasts but also facilitated the restoration of erythroid hematopoiesis.

Immune-mediated hemolytic anemia and pure red cell aplasia in a Jack Russell Terrier during treatment for hypoadrenocorticism.

An 11-year-old neutered male Jack Russell Terrier was presented to Yuki Animal Hospital for regenerative anemia during the treatment of hypoadrenocorticism. A blood smear examination showed spherocytes, polychromatic erythrocytes, and erythrocyte ghosts. The direct agglutination test was positive at 37°C. The dog was then diagnosed with immune-mediated hemolytic anemia (IMHA). Although prednisolone and mycophenolate mofetil were administered, the hematocrit and reticulocyte count decreased, and nonregenerative anemia developed. A bone marrow examination was performed to diagnose the cause of the nonregenerative anemia. Histologic and cytologic bone marrow examination revealed a normocellular to hypercellular medulla with severe erythroid hypoplasia. No proliferation of lymphocytes or lymphoblast-appearing cells was observed. This dog was diagnosed with pure red cell aplasia (PRCA). Despite treatment with immunosuppressive agents, the patient died of thrombosis. Although these associations were unclear, this is the first report of PRCA diagnosis following IMHA and while treating hypoadrenocorticism.

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.

Successful treatment pure red cell aplasia after ABO major mismatched allogeneic hematopoietic stem cell transplantation with avatrombopag and low dose rituximab.

BACKGROUND: Pure red cell aplasia (PRCA) following allogeneic hematopoietic stem cell transplantation (allo-HSCT) with ABO major incompatibility is characterized by transfusion dependent anemia. No standard treatment existed for PRCA following allo-HSCT yet. STUDY DESIGN AND METHODS: We conducted a retrospective study, and reported our experience with the use of avatrombopag and lower dose rituximab to treat five patients with PRCA subsequent to major ABO-incompatible allo-HSCT. RESULTS: Five cases of PRCA were identified from 72 patients who underwent allo-HSCT with major or bidirectional ABO mismatch. Cumulative incidence at Day +60 was 6.9% (5/72) at our center. All donor and recipient blood groups were A+  and O+ , respectively. In the first three cases we reported, patients received erythropoietin, plasma exchange, and donor lymphocyte infusion, but none of them had any effect. After 4 weeks of treatment with low dose rituximab (100 mg/week) combined with avatrombopag (40 mg/day), favorable outcomes were obtained. According to the aforementioned experience, Cases 4 and 5 were administered low-dose rituximab and avatrombopag in 3 months after transplantation, and erythroid response was observed on 3 weeks after treatment. Our patients tolerated low-dose rituximab and avatrombopag well and experienced rapid efficacy, with a median duration of 3 weeks. Furthermore, no severe infection or thrombocytosis necessitated a dose adjustment. CONCLUSION: Low-dose rituximab and avatrombopag may be an effective treatment for patients with PRCA after major ABO-incompatible allo-HSCT. The patients should be treated at least 90 days post transplantation if conventional erythropoietin therapy fails.

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.

HLA-B*46:01:01:01 and HLA-DRB1*09:01:02:01 are associated with anti-rHuEPO-induced pure red cell aplasia.

Treatment of anemia in patients with chronic kidney disease (CKD) with recombinant human erythropoietin (rHuEPO) can be disrupted by a severe complication, anti-rHuEPO-induced pure red cell aplasia (PRCA). Specific HLA genotypes may have played a role in the high incidence of PRCA in Thai patients (1.7/1,000 patient years vs. 0.03/10,000 patient years in Caucasians). We conducted a case-control study in 157 CKD patients with anti-rHuEPO-induced PRCA and 56 controls. The HLA typing was determined by sequencing using a highly accurate multiplex single-molecule, real-time, long-read sequencing platform. Four analytical models were deployed: Model 1 (additive: accounts for the number of alleles), Model 2 (dominant: accounts for only the presence or absence of alleles), Model 3 (adjusted additive with rHuEPO types) and Model 4 (adjusted dominant with rHuEPO types). HLA-B*46:01:01:01 and DRB1*09:01:02:01 were found to be independent risk markers for anti-rHuEPO-induced PRCA in all models [OR (95%CI), p-values for B*46:01:01:01: 4.58 (1.55-13.51), 0.006; 4.63 (1.56-13.75), 0.006; 5.72 (1.67-19.67), 0.006; and 5.81 (1.68-20.09), 0.005; for DRB1*09:01:02:01: 3.99 (1.28-12.49), 0.017, 4.50 (1.32-15.40), 0.016, 3.42 (1.09-10.74), 0.035, and 3.75 (1.08-13.07), 0.038, in Models 1-4, respectively. HLA-B*46:01:01:01 and DRB1*09:01:02:01 are susceptible alleles for anti-rHuEPO-induced PRCA. These findings support the role of HLA genotyping in helping to monitor patients receiving rHuEPO treatment.

Immune Checkpoint Inhibitor-Induced Pure Red Cell Aplasia: A Review of 2 Cases in Metastatic Melanoma.

BACKGROUND Immunotherapy is a novel treatment offering an alternative to traditional chemotherapeutic agents for different malignancies. Hematologic adverse reactions (HARs) related to immune checkpoint inhibitors (ICIs) are uncommon. Pure red cell aplasia (PRCA) is a rare hematologic complication of ICI therapy in metastatic melanoma with significant mortality risk despite treatment with steroids or immunosuppressive therapy. For unexplained acute anemia after exclusion of other causes, performing bone marrow biopsy is imperative to diagnose PRCA and rule out involvement of bone marrow by primary tumor. HARs can occur during ICI therapy or even after ICI therapy is stopped. ICI rechallenge, even after the development of HARs, is considered in some patients with good response to treatment of HARs from ICIs. Recurrence of HARs with the same or different type of reaction is seen in some patients. CASE REPORT Two cases of ICI-induced PRCA were confirmed on bone marrow biopsy after dual ICI treatment with nivolumab and ipilimumab in metastatic melanoma. In case 2, PRCA was successfully treated with steroids and later rechallenged with single-agent nivolumab, causing mild ICI-induced immune thrombocytopenia, which did not require treatment with steroids. CONCLUSIONS It is crucial to increase clinician awareness of the possibility of PRCA development not only during treatment with ICI but also after finishing treatment with ICI; there is high mortality associated with missing an opportunity to diagnose and treat PRCA on time with favorable results. ICI rechallenge can be considered in patients who showed response to immunotherapy, especially those with limited alternative therapeutic options.

En mann i 40-årene med transfusjonskrevende anemi.

BACKGROUND: While standard blood tests are often sufficient for an anaemia workup, sometimes more invasive diagnostic testing is required to exclude rare conditions. CASE PRESENTATION: A man in his forties contacted his general practitioner because of increasing functional dyspnoea. He had completed a course of dicloxacillin a few months previously for a skin abscess on his abdomen. Bloodwork revealed severe anaemia (haemoglobin 5.4 g/dL), which required transfusion. Subsequent testing excluded iron and vitamin deficiency anaemia, haemolysis and malignancy. Initial bone marrow biopsy was of suboptimal quality. However, repeat tissue sample supported a diagnosis of pure red cell aplasia. The patient improved with ciclosporin treatment, which was gradually tapered. INTERPRETATION: Pure red cell aplasia should be considered in patients with new onset isolated anaemia with severe reticulocytopenia. Diagnosis depends on obtaining representative tissue from bone marrow biopsy. It is difficult to conclude for this patient whether the aetiology of his pure red cell aplasia was idiopathic or secondary to recent dicloxacillin use.

Secondary Pure Red Cell Aplasia During Daratumumab/ Hyaluronidase Therapy for Multiple Myeloma.

Predominantly autoimmune in origin, severe normochromic, normocytic anemia with reticulocytopenia in the setting of the normal production of leukocytes and megakaryocytic lineages is known as pure red cell aplasia (PRCA), which is unlike aplastic anemia in which all lineages are affected due to a stem cell defect. PRCA can be primary (such as autoimmune) or acquired, which can be an acute self-limited illness or a chronic disease that may be induced by medications, including immunotherapy such as monoclonal antibodies (mAbs). Daratumumab is a mAb directed against CD38 used for the treatment of multiple myeloma and systemic amyloid light-chain amyloidosis. The intravenous formulation of daratumumab received initial FDA approval, and later approval was received for the subcutaneous formulation daratumumab and hyaluronidase-fihj. The subcutaneous version increases patient convenience and has become the preferred route of administration since its approval. We herein present the case of a patient with multiple myeloma who developed acquired DNMT3A-positive PRCA while transitioning to daratumumab/hyaluronidase after initial treatment with daratumumab.

A late relapse thymoma and pure red cell aplasia case with an over 5 years of clinical response under everolimus.

Although several agents showed some clinical activity in patients with recurrent thymoma, there is no standard treatment option. Here, we report a late relapse thymoma and pure red cell aplasia case, responsive to everolimus with over 5 years of clinical benefit following multiple lines of treatment. Everolimus controlled the rapidly progressive disease in our patient without significant toxicity.