Reticulin Fibrosis Research Articles

Essential thrombocythemia (ET) presenting as a combined cilioretinal artery occlusion (Cil.RAO) and central retinal vein occlusion (CRVO)

A 35-year-old male presented with sudden vision loss in his left eye for 1 day and was diagnosed with combined cilioretinal artery occlusion (Cil.RAO) and central retinal vein occlusion (CRVO). A multidisciplinary clinical work up was conducted to determine the underlying cause. A full blood count revealed a very high platelet count (1,147,000/mm3), prompting further hematologic investigation. Peripheral blood smear showed abundant platelet clumps, and bone marrow trephine biopsy indicated megakaryocytic hyperplasia and reticulin fibrosis (grade 1). The patient tested heterozygous for the JAK2 V617F mutation, a genetic marker for myeloproliferative disorders, and was diagnosed with essential thrombocythemia (ET). After a month of treatment with hydroxyurea 500 mg daily, his platelet count returned to normal. Thrombocythemia is associated with systemic and ocular thrombotic and embolic complications. A full blood count was pivotal in diagnosing and managing ET in this patient with combined retinal vascular disease.

Diagnostic Significance and Association of Reticulin Fibrosis in Benign Hematologic Disorders

Diagnostic Significance and Association of Reticulin Fibrosis in Benign Hematologic Disorders

Idiopathic multicentric Castleman disease with marrow fibrosis and extramedullary hematopoiesis.

Idiopathic multicentric Castleman disease (iMCD) is a rare inflammatory disorder mediated by excessive proinflammatory cytokine signaling, most notably by interleukin 6 (IL-6). IL-6-induced extramedullary hematopoiesis (EMH) has been reported in murine models of iMCD. Herein we present four cases of iMCD with EMH in humans. The index case is a 24-year-old white woman who presented with pancytopenia, hepatosplenomegaly, and diffuse lymphadenopathy (LAD) with EMH in core lymph node biopsies. We then searched ACCELERATE, a Castleman disease (CD) natural history registry, and identified three additional CD cases with EMH reported in biopsies: A 23-year-old Asian man with fatigue, edema, LAD, and splenomegaly; a 20-year-old white man with fever, dyspnea, LAD, and hepatosplenomegaly; and a 50-year-old white man with constitutional symptoms, LAD, and myelodysplastic syndrome in bone marrow with a KRAS mutation. All four patients presented with thrombocytopenia and fever and/or markedly elevated C-reactive protein. Patient 1 had iMCD-NOS (not otherwise specified) with severe thrombocytopenia, reticulin fibrosis in bone marrow, small volume LAD and organomegaly but no anasarca. The other three patients had iMCD-TAFRO (thrombocytopenia, anasarca, reticulin fibrosis, renal dysfunction, organomegaly). Two had mixed CD and two had hypervascular CD in lymph nodes. All four had bone marrow hypercellularity and megakaryocyte hyperplasia and two had reticulin fibrosis. This case series demonstrates that EMH can be seen in CD, particularly in iMCD-TAFRO. Given the similarity of this finding to previous murine models of IL-6-induced marrow and lymph node changes we hypothesize that this is an IL-6-mediated phenomenon.

Idiopathic multicentric Castleman disease-TAFRO after COVID-19: A case report.

TAFRO syndrome, a rare disease characterised by thrombocytopaenia, anasarca, fever, reticulin fibrosis, and organomegaly, is thought to be caused by hypercytokinaemia. It is a heterogeneous clinical entity, and a recent comprehensive international definition defined TAFRO syndrome with lymph node histopathology consistent with idiopathic multicentric Castleman disease (iMCD) as iMCD-TAFRO. Herein, we present a rare case of iMCD-TAFRO following coronavirus disease 2019 (COVID-19) infection. A 62-year-old Japanese woman, initially diagnosed with COVID-19, developed a persistent fever and fluid retention, prompting the diagnosis of iMCD-TAFRO. Following the initiation of prednisolone and cyclosporine, her symptoms gradually resolved. Therefore, we discuss the potential pathophysiological link between COVID-19 and iMCD-TAFRO, emphasising the role of cytokine storms. This case report highlights the importance of recognising the spectrum of inflammatory states after COVID-19 and differentiating iMCD-TAFRO after COVID-19 from the COVID-19 cytokine storm syndrome.

Concurrent myelodysplastic malignancies and plasma cell neoplasms; a clinicopathological study with prognostic implications

Plasma cell neoplasms (PCN) have infrequently been reported in patients with myelodysplastic syndrome (MDS) and even more rarely in those with myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN). We report the clinicopathologic features of 26 patients with bone marrow myelodysplasia accompanied by PCN, including 21 patients with MDS and 5 with MDS/MPN. The clinicopathologic features of the MDS/MPN-PCN were compared to those of the MDS-PCN group and 68 cases of MDS/MPN without PCN, respectively. The MDS/MPN-PCN group was notable for increased reticulin fibrosis > grade 1 when compared to both the MDS/MPN (p = 0.007) and MDS-PCN (p = 0.02) groups. MDS/MPN-PCN was associated with worse overall survival when compared with MDS-PCN (p = 0.03) and but not with MDS/MPN. Notably, hemoglobin level <8 g/dl (p = 0.008), and IDH2 somatic mutation (p = 0.003) were independent predictors of poor overall survival in all patients with MDS/MPN. Analysis of larger cohorts is required to confirm these associations and provide an insight into the pathogenesis.

Increase in Vascular Endothelial Growth Factor (VEGF) Expression and the Pathogenesis of iMCD-TAFRO.

TAFRO (thrombocytopenia (T), anasarca (A), fever (F), reticulin fibrosis (F/R), renal failure (R), and organomegaly (O)) is a heterogeneous clinical subtype of idiopathic multicentric Castleman disease (iMCD) associated with a significantly poorer prognosis than other subtypes of iMCD. TAFRO symptomatology can also be seen in pathological contexts outside of iMCD, but it is unclear if those cases should be considered representative of a different disease entity or simply a severe presentation of other infectious, malignant, and rheumatological diseases. While interleukin-6 (IL-6) is an established driver of iMCD-TAFRO pathogenesis in a subset of patients, the etiology is unknown. Recent case reports and literature reviews on TAFRO patients suggest that vascular endothelial growth factor (VEGF), and the interplay of VEGF and IL-6 in concert, rather than IL-6 as a single cytokine, may be drivers for iMCD-TAFRO pathophysiology, especially renal injury. In this review, we discuss the possible role of VEGF in the pathophysiology and clinical manifestations of iMCD-TAFRO. In particular, VEGF may be involved in iMCD-TAFRO pathology through its ability to activate RAS/RAF/MEK/ERK and PI3K/AKT/mTOR signaling pathways. Further elucidating a role for the VEGF-IL-6 axis and additional disease drivers may shed light on therapeutic options for the treatment of TAFRO patients who do not respond to, or otherwise relapse following, treatment with IL-6 targeting drugs. This review investigates the potential role of VEGF in the pathophysiology of iMCD-TAFRO and the potential for targeting related signaling pathways in the future.

TAFRO Syndrome: Guidance for Managing Patients Presenting Thrombocytopenia, Anasarca, Fever, Reticulin Fibrosis, Renal Insufficiency, and Organomegaly

TAFRO syndrome is an inflammatory disorder of unknown etiology characterized by thrombocytopenia, anasarca, fever, reticulin fibrosis, renal insufficiency, and organomegaly. Despite great advancements in research on the TAFRO syndrome in the last decade, its diagnosis and treatment are still challenging for most clinicians because of its rarity and severity. Since the initial proposal of the TAFRO syndrome as a distinct disease entity in 2010, two independent diagnostic criteria have been developed. Although these are different in the concept of whether TAFRO syndrome is a subtype of idiopathic multicentric Castleman disease or not, they are similar except for the magnitude of lymph node histopathology. Because there have been no specific biomarkers, numerous diseases must be ruled out before the diagnosis of TAFRO syndrome is made. The standard of care has not been fully established, but interleukin-6 blockade therapy with siltuximab or tocilizumab and anti-inflammatory therapy with high-dose corticosteroids are the most commonly applied for the treatment of TAFRO syndrome. The other immune suppressive agents or combination cytotoxic chemotherapies are considered for patients who do not respond to the initial treatment. Whereas glowing awareness of this disease improves the clinical outcomes of patients with TAFRO syndrome, further worldwide collaborations are warranted.

Biomarkers and Signaling Pathways Implicated in the Pathogenesis of Idiopathic Multicentric Castleman Disease/Thrombocytopenia, Anasarca, Fever, Reticulin Fibrosis, Renal Insufficiency, and Organomegaly (TAFRO) Syndrome.

Idiopathic multicentric Castleman disease (iMCD) and TAFRO syndrome present a variety of symptoms thought to be caused by excessive inflammatory cytokines and chemokines, but the underlying mechanisms are unknown. iMCD is broadly classified into two types: iMCD-NOS and iMCD-TAFRO, which have distinct laboratory findings, pathological features, and responses to treatments. It is thought that iMCD-NOS, particularly the IPL type, responds favorably to IL-6 inhibitors due to its IL-6-centric profile. iMCD-TAFRO frequently progresses acutely and seriously, similar to TAFRO syndrome. Elevated levels of cytokines, including IL-1β, TNF-α, IL-10, and IL-23, as well as chemokines like CXCL13 and CXCL-10 (especially in iMCD-TAFRO), SAA, and VEGF, have been linked to the disease's pathology. Recent research has identified key signaling pathways including PI3K/Akt/mTOR and JAK-STAT3, as well as those regulated by type I IFN, as crucial in iMCD-TAFRO. These results suggest that dominant pathways may vary between subtypes. Further research into the peripheral blood and lymph nodes is required to determine the disease spectrum of iMCD-NOS/iMCD-TAFRO/TAFRO syndrome.

Unraveling TAFRO Syndrome: An In-Depth Look at the Pathophysiology, Management, and Future Perspectives.

TAFRO syndrome is a rare and aggressive inflammatory entity characterized by thrombocytopenia, anasarca, fever, renal failure, reticulin fibrosis, and organomegaly. This entity supposes a diagnostic and therapeutic challenge due to its significant overlap with Castleman's disease. However, distinct clinical and histological features warrant its classification as a separate subtype of idiopathic multicentric Castleman's disease (iMCD). While recent modifications have been made to the diagnostic criteria for iMCD, these criteria lack specificity for this particular condition, further complicating diagnosis. Due to its inflammatory nature, several complex molecular signaling pathways are involved, including the JAK-STAT pathway, NF-kB, and signal amplifiers such as IL-6 and VEGF. Understanding the involvement of immune dysfunction, some infectious agents, genetic mutations, and specific molecular and signaling pathways could improve the knowledge and management of the condition, leading to effective treatment strategies. The current therapeutic approaches include corticosteroids, anti-IL6 drugs, rituximab, and chemotherapy, among others, but response rates vary, highlighting the need for personalized strategies. The prognosis is uncertain due to diagnostic difficulties, emphasizing the importance of early intervention and appropriate targeted treatment. This comprehensive review examines the evolving landscape of TAFRO syndrome, including the pathophysiology, diagnostic criteria, treatment strategies, prognosis, and future perspectives.

Bone marrow findings post allogeneic transplant for myeloproliferative neoplasms and chronic myelomonocytic leukemia with increased fibrosis.

Allogeneic hematopoietic stem cell transplant for myeloid neoplasms with increased fibrosis is uncommon; morphologic features posttransplant can be concerning for persistent disease. In this retrospective study, we identified 22 patients transplanted for myeloproliferative neoplasms or chronic myelomonocytic leukemia with fibrosis at our institution, and reviewed slides from pretransplant and posttransplant bone marrow biopsies. Clinical features and results of molecular, chimerism, and cytogenetic studies were retrieved from the medical record. Pretransplant bone marrow biopsies commonly exhibited hypercellularity, atypical megakaryocytes, and reticulin fibrosis. At day 100, 36% of biopsies had reticulin grade >MF1 and 33% of those tested had positive molecular studies, with no significant associations between day 100 marrow characteristics and molecular profile or peripheral count recovery times. In the 1 year posttransplant biopsies (n = 12), 7 of 9 had negative molecular studies; of these, none had reticulin grade >MF1, 1 had trichrome 1+, 2 had atypical megakaryocytes, and 1 was hypercellular. Supporting recent literature, our study indicates that persistent day 100 reticulin fibrosis/collagen deposition does not show an association with day 100 molecular status. Our study additionally provides data for 12 patients with 1 year posttransplant marrow biopsies, with the majority of those lacking either increased fibrosis or molecular evidence of persistent disease.

Radiological Imaging Findings of Adrenal Abnormalities in TAFRO Syndrome: A Systematic Review.

This systematic review article aims to investigate the clinical and radiological imaging characteristics of adrenal abnormalities in patients with thrombocytopenia, anasarca, fever, reticulin fibrosis, renal dysfunction, and organomegaly (TAFRO) syndrome. We searched the literature in PubMed, the Cochrane Library, and the Web of Science Core Collection. Ultimately, we analyzed 11 studies with 22 patients plus our 1 patient, totaling 23 patients. The mean age was 47.0 ± 12.6 years. There were 20 male and 3 female patients, respectively. The histopathological analysis of lymph nodes was conducted in 15 patients (65.2%), and the diagnosis was consistent with TAFRO syndrome in all 15 patients. Among the 23 patients, 11 patients (18 adrenal glands) showed adrenal ischemia/infarction, 9 patients (13 adrenal glands) showed adrenal hemorrhage, and 4 patients (7 adrenal glands) showed adrenomegaly without evidence of concurrent ischemia/infarction or hemorrhage. One patient demonstrated unilateral adrenal hemorrhage and contralateral adrenomegaly. In patients with adrenal ischemia/infarction, the adrenal glands displayed poor enhancement through contrast-enhanced computed tomography (CT). In patients with adrenal hemorrhage, the adrenal glands revealed high attenuation through non-enhanced CT and hematoma through magnetic resonance imaging. Adrenomegaly, with or without adrenal ischemia/infarction or hemorrhage, was observed in all patients (23/23, 100%). The subsequent calcification of the affected adrenal glands was frequently observed (9/14, 64.3%) when a follow-up CT was performed. Abdominal pain was frequent (15/23, 65.2%), all of which occurred after the disease's onset, suggesting the importance of considering TAFRO syndrome as a cause of acute abdomen. Given the absence of evidence of adrenal abnormalities in non-TAFRO-idiopathic multicentric Castleman disease (iMCD), they may serve as diagnostic clues for differentiating TAFRO syndrome from non-TAFRO-iMCD.

Abstract 7225: Combination JAK1/2 and CDK8/19 inhibition demonstrates enhanced efficacy in myeloproliferative neoplasms

Abstract Myeloproliferative neoplasms (MPNs) are characterized by aberrant activation of the JAK-STAT pathway. Ruxolitinib (RUX) is a JAK1/2 inhibitor used to treat myelofibrosis (MF) and hydroxyurea-resistant/intolerant polycythemia vera. While RUX has demonstrated important clinical benefits, a large proportion of patients have persistent disease manifestations despite therapy. CDK8 regulates phosphorylation of STAT proteins in a RUX-independent manner; thus, CDK8 inhibition may alter downstream STAT target gene expression. RVU120 is a highly selective and potent CDK8/19 inhibitor that inhibits STAT1/5 phosphorylation. We hypothesized that the combination of RUX and RVU120 would act in a cooperative manner to attenuate JAK-STAT signaling and reduce MPN phenotypes in vivo. Using JAK2V617F mutant leukemic cell lines, we identified dose-responsive changes in viability with RUX and RVU120 in all cell lines. Pharmacodynamic analysis validated that STAT5 protein phosphorylation was decreased by RUX/RVU120, although at different phosphorylation sites by RUX (pTYR694) and RVU120 (pSER726/731); exposure to RUX+RVU120 inhibited phosphorylation at both sites. Notably, analysis of combinatorial effects of RUX+RVU120 on viability demonstrated drug synergies (combinatorial index &amp;lt;1) in RUX-naïve and resistant SET-2 cells. Nascent RNA expression data exploring JAK-STAT and mediator-related pathways of pathogenesis will be presented at the meeting. For in vivo studies, we used two previously-described murine models of MF and PV. Briefly, retrovirally-transfected (MSCV-MPLW515L-IRES-GFP) or Jak2V617F-conditional knock-in bone marrow (BM) was intravenously injected into lethally-irradiated congenic recipients. Mice were randomized and treated for several weeks with vehicle (VEH), single-agent RUX/RVU120, or RUX+RVU120 arms. Spleen weights between VEH and RUX/RVU120 treated mice at time of terminal sacrifice were significantly reduced across both models (p⇐0.009). In MPLW515L mice, WBCs and PB GFP% were significantly reduced (p&amp;lt;0.002) and histopathology demonstrated near-elimination of BM reticulin fibrosis and improved trilineage hematopoiesis between RUX+RVU120 and RUX arms. Data on overall survival, cytokine profiles, and the impact of RVU120 on dynamic gene expression will be presented at the meeting. The combination of RVU120 and RUX demonstrated biochemical synergy and differential inhibition of STAT5 phosphorylation in vitro. Further, in vivo treatment with RVU120/RUX+RVU120 resulted in significant reductions of disease manifestation (splenomegaly, WBC, fibrosis scoring, hematopoiesis) when compared to VEH/RUX. These data nominate JAK1/2 and CDK8/19 inhibition as a potential novel therapeutic strategy in MPNs; further work on nascent RNA expression and cytokine profiles will potentially elucidate additional mechanisms of action. Citation Format: Zachary Zaroogian, Elżbieta Adamczyk, Adrianna Moszyńska, Marta Obacz, Urszula Pakulska, Benjamin Durham, Milena Mazan, Shoron Mowla, Katarzyna Wnęk, Amritha Varshini Hanasoge Somasundara, Beata Barczuk, Aniela Gołas, Ross Levine, Tomasz Rzymski, Raajit Rampal. Combination JAK1/2 and CDK8/19 inhibition demonstrates enhanced efficacy in myeloproliferative neoplasms [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7225.

TAFRO Syndrome: A Syndrome or a Subtype of Multicentric Castleman Disease?

TAFRO (thrombocytopenia, anasarca, fever, reticulin fibrosis of bone marrow/renal dysfunction, organomegaly) syndrome is a systemic inflammatory disorder of unknown etiology. It has been recognized as a subtype of idiopathic multicentric Castleman disease (iMCD), and the international diagnostic criteria for iMCD-TAFRO require a lymph node histopathology consistent with iMCD. Furthermore, TAFRO syndrome is defined as a heterogeneous clinical entity caused by underlying diseases such as malignancy, autoimmune diseases, or infections. However, the cases that led to the proposal of TAFRO syndrome lacked recognizable lymphadenopathy and were inconsistent with any other diseases, despite vigorous efforts in differential diagnosis. Irrespective of the presence or absence of Castleman disease (CD)-like histology, TAFRO syndrome exhibits homogeneous clinical, laboratory, and prognostic features, setting it apart from iMCD without TAFRO syndrome. Defining iMCD-TAFRO apart from TAFRO syndrome is deemed meaningless and confusing. MCD is a heterogeneous lymphoproliferative disorder consisting of several subtypes with different pathogenesis, clinical manifestations, and histological features. Typical MCD in Japan, characterized by the histology of plasma cell type and marked polyclonal hypergammaglobulinemia, is identical to idiopathic plasmacytic lymphadenopathy with polyclonal hyperimmunoglobulinemia (IPL). Although IPL is classified into iMCD-NOS (not otherwise specified), it should be recognized as a distinct clinicopathological entity. Furthermore, we propose to separate TAFRO syndrome from the MCD category as a defined disorder.

Idiopathic multicentric Castleman disease (iMCD)-idiopathic plasmacytic lymphadenopathy: A distinct subtype of iMCD-not otherwise specified with different clinical features and better survival.

Idiopathic multicentric Castleman disease (iMCD) is subclassified into iMCD-thrombocytopenia, anasarca, reticulin fibrosis, renal dysfunction, organomegaly (TAFRO) and iMCD-not otherwise specified (NOS) according to the Castleman Disease Collaborative Network (CDCN) consensus criteria. With a deeper understanding of iMCD, a group of patients with iMCD-NOS characterised by polyclonal hypergammaglobulinaemia, plasmacytic/mixed-type lymph node histopathology and thrombocytosis has attracted attention. This group of patients has been previously described as having idiopathic plasmacytic lymphadenopathy (IPL). Whether these patients should be excluded from the current classification system lacks sufficient evidence. This retrospective analysis of 228 patients with iMCD-NOS identified 103 (45.2%) patients with iMCD-IPL. The clinical features and outcomes of patients with iMCD-IPL and iMCD-NOS without IPL were compared. Patients with iMCD-IPL showed a significantly higher inflammatory state but longer overall survival. No significant difference in overall survival was observed between severe and non-severe patients in the iMCD-IPL group according to the CDCN severity classification. Compared with lymphoma-like treatments, multiple myeloma-like and IL-6-blocking treatment approaches in the iMCD-IPL group resulted in significantly higher response rates and longer time to the next treatment. These findings highlight the particularities of iMCD-IPL and suggest that it should be considered a new subtype of iMCD-NOS.

TAFRO syndrome associated with C3 nephropathy (an analysis of clinical experience)

Aim. To present a clinical case of TAFRO syndrome – a recently described subtype of idiopathic multicentric Castleman disease of unknown etiology, characterized by thrombocytopenia, anasarca, fever, reticulin fibrosis of the bone marrow and / or renal dysfunction, organomegaly associated with an increase in serum IL-6 secretion.Materials and methods. Herein, we report a young patient diagnosed with TAFRO combined with C3 nephropathy. The patient was treated with glucocorticoids (methylprednisolone), colchicine, sarilumab, rivaroxaban, and symptomatic treatment.Results. Key aspects of diagnosis, treatment and course of the syndrome were discussed. The possibility of the combined course of two rare pathologies – a subtype of idiopathic multicentric Castleman disease and C3 nephropathy is still unclear.Conclusion. The diagnosis of TAFRO syndrome can be considered after the exclusion of a number of infectious, paraneoplastic, systemic connective tissue diseases, POEMS syndrome, liver cirrhosis against the background of autoimmune hepatitis, autoimmune thrombocytopenic purpura, as well as hemolytic-uremic syndrome. Kidney damage in this category of patients, in most of the described clinical cases, is morphologically represented by thrombotic microangiopathy or mesangioproliferative glomerulonephritis. C3 nephropathy in that clinical case seems to be concomitant. Glucocorticoids in high and ultrahigh doses, cyclosporine, IL-6 type inhibitors, as well as anti-CD20 antibodies are used as therapy.

Transcriptome analysis of the cytokine storm-related genes among the subtypes of idiopathic multicentric Castleman disease.

Idiopathic multicentric Castleman disease (iMCD) is a type of Castleman disease unrelated to the Kaposi sarcoma-associated herpesvirus/human herpesvirus type 8 (KSHV/HHV8) infection. Presently, iMCD is classified into iMCD-IPL (idiopathic plasmacytic lymphadenopathy), iMCD-TAFRO (thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly), and iMCD-NOS (not otherwise specified). The most common treatment for iMCD is using IL-6 inhibitors; however, some patients resist IL-6 inhibitors, especially for iMCD-TAFRO/NOS. Nevertheless, since serum IL-6 levels are not significantly different between the iMCD-IPL and iMCD-TAFRO/NOS cases, cytokines other than IL-6 may be responsible for the differences in pathogenesis. Herein, we performed a transcriptome analysis of cytokine storm-related genes and examined the differences between iMCD-IPL and iMCD-TAFRO/NOS. The results demonstrated that counts per million of STAT2, IL1R1, IL1RAP, IL33, TAFAIP1, and VEGFA (P < 0.001); STAT3, JAK2, MAPK8, IL17RA, IL18, TAFAIP2, TAFAIP3, PDGFA, VEGFC, CXCL10, CCL4, and CXCL13 (P < 0.01); and STAT1, STAT6, JAK1, MAPK1, MAPK3, MAPK6, MAPK7, MAPK9, MAPK10, MAPK11, MAPK12, MAPK14, NFKB1, NFKBIA, NFKBIB, NFKBIZ, MTOR, IL10RB, IL12RB2, IL18BP, TAFAIP6, TNFAIP8L1, TNFAIP8L3, CSF2RBP1, PDGFB, PDGFC, and CXCL9 (P < 0.05) were significantly increased in iMCD-TAFRO/NOS. Particularly, upregulated IL33 expression was demonstrated for the first time in iMCD-TAFRO/NOS. Thus, inflammatory signaling, such as JAK-STAT and MAPK, may be enhanced in iMCD-TAFRO/NOS and may be a cytokine storm.

Improvement of tissue fibrosis in TAFRO syndrome by prednisolone monotherapy

We report the case of a 48-year-old man who presented with fatigue and weight loss. A local physician observed elevated alkaline phosphatase levels, anemia, thrombocytopenia, and renal dysfunction. Fever also appeared, and the patient was admitted to our hospital. Computed tomography revealed hepatosplenomegaly, pleural and ascitic fluid, and left axillary lymphadenopathy. Bone marrow biopsy indicated hyperplasia with increased megakaryocytes and reticulin fibrosis. Axillary lymph node biopsy showed Castleman's disease-like features. Liver biopsy revealed proliferation of reticulin fibrosis. Therefore, TAFRO syndrome was diagnosed and treatment with 1 mg/kg prednisolone was started. Anemia and thrombocytopenia improved, and after 24 weeks of treatment, serum hyaluronic acid and type IV collagen decreased to the normal range. Bone marrow biopsy after 18 weeks of treatment showed decreased reticular fibers. In TAFRO syndrome, improvement of liver and bone marrow fibrosis can be expected with adequate intervention, and serum hyaluronic acid and type IV collagen are useful for evaluating fibrosis.

Clinical and Prognostic Validation of the Reticulin, Collagen, Osteosclerosis (RCO) Score for Primary Myelofibrosis (PMF)

Introduction: Primary myelofibrosis (PMF) is hallmarked by stromal bone marrow (BM) changes that include reticulin fibrosis, collagen deposition, osteosclerosis, and microvascular proliferation. Accurate evaluation of BM fibrotic changes is key for MF diagnosis and deserves prognostic implications. Gianelli et al. ( Histopathol 2017;71:89) developed a comprehensive score, named reticulin (MF), collagen (Co), osteosclerosis (Ost) score (RCOs), which was prognostically informative and more accurate than the 2005 European Consensus on Grading of Bone Marrow Fibrosis (ECGMF) in identifying high-risk patients (pts). Aims&amp;Methods: This retrospective, single-center study aimed to validate the RCOs and explore its clinical, genetic and prognostic correlates in a large cohort of clinically and molecularly annotated PMF pts diagnosed according to 2022 ICC criteria. The RCOs was assessed by two independent experienced histopathologists (U.G, R.S.). Results: The study included 222 pts with a diagnosis of PMF: 121 (55%) prefibrotic PMF (pre-PMF), 101 (45%) overt PMF. Median age was 66 years (range, 18-91), 127 (57%) were male. BM histological analysis according to the RCO algorithm provided the following results: MF-0 n=20 (9%), MF-1 n=102 (46%), MF-2 n=47 (21%), and MF-3 n=53 (24%); Co-0 n=130 (59%), Co-1 n=33 (15%), Co-2 n=31 (14%), and Co-3 n=28 (13%); Ost-0 n=146 (66%), Ost-1 n=45 (20%), Ost-2 n=18 (8%), and Ost-3 n=13 (6%). Next, we looked at the distribution of the Co and Ost variables according to MF grade and PMF diagnosis. Overall, morphological features evolved harmonically, with pre-PMF showing the less severe stromal changes and higher reticulin fibrosis being associated with the highest values of Co and Ost. Computation of the RCOs returned the following results: RCOs 0 n=20 (9%), RCOs 1 n=94 (42%), RCOs 2 n=15 (7%), RCOs 3 n=19 (9%), RCOs 4 n=9 (4%), RCOs 5 n=16 (7%), RCOs 6 n=13 (6%), RCOs 7 n=17 (8%), RCOs 8 n=11 (5%), and RCOs 9 n=8 (4%). Median RCOs for pts with pre- and overt PMF was 1 (range, 0-2) and 5 (range, 2-9), respectively. We investigated the correlations of RCOs with clinical and molecular variables. Higher RCOs was associated with overt PMF (median, 5 vs 1, P&amp;lt;.0001), male gender (median, 3 vs 1, P=.0005), lower hemoglobin (Pearson's r, -0.5, P&amp;lt;.0001), lower platelets (Pearson's r, -0.4, P&amp;lt;.0001), higher blasts (Pearson's r, 0.4, P&amp;lt;.0001), higher LDH (Pearson's r, 0.5, P&amp;lt;.0001), and higher prevalence of splenomegaly (median, 3 vs 1, P&amp;lt;.0001) and constitutional symptoms (median, 5 vs 1, P=.0004). As to molecular variables, a higher RCOs was associated with abnormal karyotype (median, 3 vs 1, P=.0003), absent JAK2 mut (median, 2 vs 1, P=.0224) but higher JAK2 allele burden in JAK2-mut pts (Pearson's r, 0.3, P&amp;lt;.0006), triple negativity (median, 5 vs 1, P=.0223), EZH2 mut (median, 6 vs 1, P=.0033), ASXL1 mut (median, 6 vs 1, P&amp;lt;.0001), KRAS mut (median, 8 vs 1, P=.0059), and HMR status (i.e., ≥1 mut in ASXL1, EZH2, IDH1/2, SRSF2) (median, 5 vs 1, P&amp;lt;.0001). Median overall survival (OS) was 96 months (95% CI 81-134). In univariate Cox regression analysis, RCOs directly correlated with risk of death (HR 3.1, 95% CI 1.5-6.3, P=.0023). MF and Co variables correlated with OS (respectively: HR 4.0, 95% CI 1.8-8.6, P=.0003; HR 2.7, 95% CI 1.5-5.0, P=.0008), unlike Ost. ROC analysis with death as endpoint confirmed 5 as the optimal cut-off value ( Histopathol 2017;71:89). Pts with RCOs &amp;gt;5 (n=65 overt PMF) had significantly worst OS compared to pts with RCOs &amp;lt;5 (n=121/36 pre-/overt PMF), with median values of 64 vs 134 months (HR 2.3, 95% CI 1.4-3.6, P=.0004) (Fig. 1A). Considering only overt PMF pts, ROC analysis confirmed 5 as the more accurate cut-off value (univariate survival analysis: HR 2.1, 95% CI 1.1-4.2, P=.0257). We finally computed the MIPSS70 by replacing the original BM fibrosis grade ≥2 variable with the dichotomous RCOs 5 ( &amp;gt;/&amp;lt;5) in 177 (80%) pts with full molecular information, and calculated the C-index, Brier score, and time-dependent area under the curve (AUC) (Fig. 1B). The highest values for performance and accuracy in predicting death were achieved by the RCOs 5-integrated MIPSS70 at 12, 36, and 48 months. Conclusions: Our findings confirm the clinical and prognostic consistency of RCOs, supporting the importance of a comprehensive and accurate evaluation of BM stromal changes in PMF. Integration of RCOs within the MIPSS70 might improve the predictive performance of the model.

Morphologic and Genetic Features of Unclassifiable Chronic Myeloid Neoplasms: Five-Year Experience of a Canadian Provincial Referral Center

Introduction: The challenge of diagnosing and definitively classifying myeloproliferative neoplasms (MPNs) and myelodysplastic/myeloproliferative neoplasms (MDS/MPNs) remains a conundrum in the field of hematology. While the World Health Organization has outlined diagnostic criteria for various categories, there remain cases that elude specific classification, falling under the umbrella of MPN, unclassifiable (MPN-U) and MDS/MPN, unclassifiable (MDS/MPN-U). In this study, we aimed to compare the morphological and genetic profiles of cases classified as MPN-U or MDS/MPN-U against more definitively classified cases (including chronic myelomonocytic leukemia (CMML), essential thrombocythemia (ET), MDS/MPN with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T), and primary myelofibrosis (PMF), including prefibrotic PMF (pre-PMF)). Methods: Morphologically unclassifiable myeloid neoplasm cases referred for pathologist review to our laboratory in the largest tertiary care center in British Columbia, Canada were identified through pathology database query over a five-year period. Bone marrow materials were reviewed and reanalyzed with standardized collection of qualitative and semiquantitative data by two hematopathologists. Morphological parameters studied included the myeloid to erythroid ratio, bone marrow cellularity, lineage dysplasia, megakaryocyte histotopography, bone marrow blast frequency, fibrotic changes, and bone marrow vascularity, among others. Clinical data, cytogenetic findings, and results of a targeted sequencing panel assessing a set of approximately 50 genes recurrently mutated in myeloid malignancies were collected by electronic medical record review. A cohort of contemporarily collected myeloid neoplasms with definitive pathologic diagnoses was reviewed for comparison. Statistical analyses were performed using python3. Results: The cohort comprised 29 cases classified as MPN-U, 12 cases of MDS/MPN-U, and 5 cases each of ET, PMF, pre-PMF, CMML, and MDS/MPN-RS-T. MPN-U cases were further subcategorized based on the apparent reason for difficulty in classification, including: overlapping features with another MPN; late stage/overt fibrosis; early stage without fully-developed morphologic features; and coexisting atypical morphologic findings. MPN-U with overlapping features had highly variable reticulin fibrosis, while, as expected, late stage entities had a high degree of reticulin fibrosis and early stage entities showed less overt fibrosis (Figure, Left, demonstrating select morphologic features of evaluated chronic myeloid neoplasms). MPN-U as a whole appeared to show less prominent fibrosis-associated findings than MDS/MPN-U and to, in general, show a greater degree of neovascularization, similar to changes observed in cases with PMF. Splicing factor and epigenetic modifier mutations appeared to be overrepresented in MDS/MPN-U relative to MPN-U, notably excluding MPN-U with atypical morphologic features (Figure, Right, demonstrating the distribution of pathogenic variants identified in evaluated myeloid neoplasms; results are indicated as presence (1) or absence (0) of a variant for each gene). Notably, no CALR mutations were identified in the MDS/MPN-U category or early stage / atypical morphology MPN-U, though they were enriched in overtly fibrotic MPN-U entities. Discussion/Conclusion: In this cohort we observed, as expected, significant overlap in cases classified as MPN-U and MDS/MPN-U with better delineated entities, though patterns of morphologic change and mutational spectra suggest potential directions for further investigation of additional criteria that may guide accurate classification of these neoplasms. These findings reflect the heterogeneity of MPNs described in the literature and the complexity of their genetic underpinnings, particularly in the context of concurrent dyshematopoiesis; suggest enhanced bone marrow vascularization may be an informative differential diagnostic criterion in evaluation of these neoplasms, though further study is required; and emphasize the need for broader genetic testing and perhaps further subtyping of MPN-U cases for a more nuanced analytical approaches for these disorders.

Calr+ Myelofibrosis/BCR-ABL Chronic Myeloid Leukemia Overlap Syndrome Treated with Asciminib

Introduction Myeloproliferative neoplasms are considered mutually exclusive, and reports of co-occurring mutations are rare. Over the past 10 years, approximately two dozen case reports have been published of co-occurring BCR-ABL positive and CALR positive patients. Here we present the case of a patient who was reported to have myelofibrosis (MF)/myeloproliferative neoplasm (MPN), later developed chronic myeloid leukemia (CML), and ultimately progressed to acute myeloid leukemia (AML). This is unique in the literature reviewed, and may be the first reported case of this overlap syndrome being treated with asciminib. Case presentation A 40-year old male was diagnosed in 2018 with MF/MPN based upon a hypercellular bone marrow biopsy with diffuse reticulin fibrosis. He was negative for JAK2, but was not tested for CALR or MPL mutations. Treatment was ruxolitinib and hydroxyurea. Two years later, the patient was diagnosed with CML after being admitted for recurrent fevers, headache, and shortness of breath. At that time, a type 2 CALR mutation (CALR K385Nfs*47) was noted. He started dasatinib and decitabine, which resulted in a drop from 28.31% BCR-ABL to 0.0196% (Table 1A). However, hyperuricemia and renal failure led to a change in regimen and the patient was started on asciminib and ropeginterferon alfa-2b-njft in January 2022. By December, the patient's BCR-ABL PCR dropped below quantification, but he received a diagnosis of AML based on a bone marrow biopsy which showed 43% blasts. He received cladribine and cytarabine, but was found to have leukemic infiltration of the spinal cord five months later. The patient was referred to hospice and passed away in June 2023. Discussion To our knowledge, this is the first MPN-CML patient reported to have been treated with asciminib. This case illustrates its effectiveness in treating CML, but highlights the need for improved treatments for CALR+ MPN. Moreover, this case illustrates the importance of testing for CALR, MPL, and BCR-ABL in addition to JAK2 immediately when a patient presents with an MPN. It is unknown whether this patient's CALR mutation preceded the BCR-ABL translocation, and there is debate in the literature with respect to mutation chronology. The patient's BCR-ABL burden dropped from 28.31% to 0.0196% while the CALR burden remained around 94% over the same period (Table 1B). Thus, it is unlikely that the BCR-ABL mutation preceded the CALR mutation within the same clone. The patient's &amp;gt;90% CALR allele burden is higher than reported in the other reported cases, where the burden ranged from 10% to 68%. Furthermore, none of the other cases were reported to progress to AML, though follow up data is lacking. The heavy allelic burden in our patient may have been a contributing factor to the development of AML, as has been reported elsewhere. The patient's overall mutational profile is of interest. Type 2 CALR mutations have been reported to have less favorable prognoses than type 1 mutations. In addition to the CALR and BCR-ABL mutations, the patient had ASXL1 A861Hfs*6, EZH2 D730*, and NRAS G12V. All three mutations are associated with unfavorable outcomes in MDS, AML, and/or CML. Genomic instability has been discussed in relation to both CML and JAK2-positive MPN. Our patient's heavy mutational burden suggests CALR-positive neoplasms may also present against a background of inherent genomic instability. Conclusion We reported a case of MPN, followed by CML, and then AML. The patient was positive for CALR and BCR-ABL. He achieved a complete response in CML after targeted treatment, with asciminib consolidating the gains the patient made on earlier therapies. However, he always maintained a high CALR burden. This patient's mutational profile and disease course argue for the importance of early testing for CALR and BCR-ABL in addition to JAK2 and MPL in the setting of an MPN and for further research into the underlying causes of these overlap conditions.