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.

TAFRO Syndrome: A Disease Requiring Immediate Medical Attention.

TAFRO syndrome was first described in 2010, standing for thrombocytopenia, anasarca, fever, reticulin fibrosis and organomegaly. Because the lymph node histopathology of TAFRO syndrome mimics idiopathic multicentric Castleman disease (iMCD), some researchers consider TAFRO syndrome to be a subtype of iMCD. However, the clinical features of TAFRO syndrome considerably differ from those of iMCD without TAFRO. The clinical features of patients with TAFRO syndrome with or without iMCD-histopathology are similar, and these patients require an accurate diagnosis and urgent treatment. Although a histological diagnosis, including a differential diagnosis, is important, lymph node involvement in patients with TAFRO syndrome is usually modest or sometimes absent. Furthermore, a bleeding tendency due to thrombocytopenia and severe anasarca hampers performing a biopsy. Nonetheless, patients with various other disorders may manifest TAFRO syndrome-like symptoms, making the differential diagnosis in borderline cases difficult. Therefore, the establishment of precise and specific biomarkers is important.

Castleman disease and TAFRO syndrome.

Although Castleman disease was first described in 1956, this disease includes various conditions, including unicentric Castleman disease with hyaline vascular histology, human herpesvirus-8 (HHV-8) related multicentric Castleman disease, idiopathic multicentric Castleman disease, and mimics of Castleman disease associated with other conditions. To date, Castleman disease remains incompletely understood due to its rareness and difficulties in clinical and pathological diagnosis. TAFRO syndrome was reported in Japan in 2010. Because lymph node histology is similar in patients with TAFRO syndrome and Castleman disease, TAFRO syndrome is described as a related disorder of Castleman disease. Clinically, however, these conditions differ markedly. Although elevated interleukin-6 (IL-6) expression is characteristic of Castleman disease, increased expression of IL-6 may occur in patients with other diseases, making elevated IL-6 unsuitable for differential diagnosis. Further understanding of these disorders requires the identification of novel disease-specific biomarkers. This review article therefore outlines the characteristics of Castleman disease and TAFRO syndrome.

Patient's age and D-dimer levels predict the prognosis in patients with TAFRO syndrome.

OBJECTIVES: To identify prognostic factors for TAFRO syndrome, a rare inflammatory disorder of unknown etiology characterized by thrombocytopenia, anasarca, fever, reticulin myelofibrosis, renal dysfunction, and organomegaly. METHODS: Data of patients with TAFRO syndrome were extracted from a Japanese patient registry. Patients were divided into groups according to the clinical and laboratory parameters at initial presentation. Cut-off values for the laboratory parameters were determined using receiver operating characteristic curve analysis and by clinical relevance. Patient survival was analyzed by the Kaplan-Meier method. Univariable analysis was performed using log-rank tests. Multivariable analyses were performed with the logistic regression model and the Cox proportional hazards model. RESULTS: We extracted the data of 83 patients with TAFRO syndrome from the registry. Univariable analysis identified several potential prognostic factors. Of these factors, age ≥60 years and D-dimer ≥18 µg/dL remained significant predictors of poor overall survival in the multivariable Cox proportional hazards model. Based on these results, we developed a simple prognostic scoring system for TAFRO syndrome (TS-PSS). CONCLUSION: Patients in our cohort were stratified into low, intermediate, and high-risk groups by the TS-PSS. This system should be verified with independent patient cohorts in future studies.

Optimal treatments for TAFRO syndrome: a retrospective surveillance study in Japan.

TAFRO syndrome is a systemic inflammatory disorder of unknown etiology characterized by thrombocytopenia, anasarca, fever, reticulin myelofibrosis, renal dysfunction, and organomegaly. Mortality in patients with this syndrome is high; however, an optimal treatment strategy has not been established. To explore the strategy, we retrospectively analyzed 81 patients with TAFRO syndrome registered in the Multicenter Collaborative Retrospective Study for Establishing the Concept of TAFRO Syndrome in Japan by December 2019. Sixty-eight patients received corticosteroid therapy as the first-line treatment, and as the second-line treatment, 21 received tocilizumab (Toc), 14 received cyclosporine A (CsA), and 8 received rituximab (Rit) in addition to corticosteroids. We compared these second-line treatment groups by setting the primary endpoint as time to next treatment or death (TTNT). Kaplan-Meier analysis showed that the median TTNT in the Toc, CsA, and Rit groups were 2.8 months, 9.2 months, and not reached, respectively. The TTNT of the Rit group was significantly longer than that of the Toc group. In contrast, there were no significant differences in overall survival between groups, indicating that subsequent salvage therapies rescued a large proportion of patients who failed the second-line treatments. Further studies are warranted to establish the optimal treatment strategies for this syndrome.

Epidemiological analysis of multicentric and unicentric Castleman disease and TAFRO syndrome in Japan.

Castleman disease is a polyclonal lymphoproliferative disease which is clinically classified into unicentric (UCD) and multicentric (MCD). TAFRO syndrome is a relatively new concept that partly overlaps with MCD. Due to their rarity, their incidence remains unknown. This study investigated the incidence and prevalence of UCD, MCD, and TAFRO syndrome in Japan using a fixed-point observation method based on their incidence in Ishikawa prefecture. The annual incidences of MCD, UCD, and TAFRO syndrome in Japan were 309-731, 71-542, and 110-502, respectively, yielding annual incidence rates per million individuals of 2.4-5.8, 0.6-4.3, and 0.9-4.9, respectively, and nationwide prevalence of 4,180-14,900, 1,350-10,300, and 860-7,240, respectively. In conclusion, MCD, UCD and TAFRO syndrome may not be as rare as previously estimated in Japan.

The potential role of follicular helper T cells in idiopathic multicentric Castleman disease with and without TAFRO syndrome.

Idiopathic multicentric Castleman disease (iMCD) is a systemic inflammatory disease of unknown etiology caused by hypercytokinemia. Recently, TAFRO (thrombocytopenia, anasarca, fever, renal failure or reticulin fibrosis, and organomegaly) syndrome has been reported, which shows similar histopathological findings to iMCD and factors associated with a poor prognosis. iMCD shows no plasma cell infiltration in the germinal center (GC), but CD38-positive (CD38+)-plasma cells are observed in the interfollicular area. Our previous report revealed that atrophic change of GC, glomeruloid vascular proliferation, and abnormal proliferation of follicular dendritic cells are more prominent in iMCD with TAFRO (TAFRO+) in comparison to iMCD without TAFRO (TAFRO-). In addition, the numbers of CD38+ and immunoglobulin G4-positive (IgG4+) plasma cells were decreased in the interfollicular area. The roles of T follicular helper cells (Tfh) are well-known to assist B-cell proliferation, maturation, and differentiation．It maintains the formation of GC and is also related in the class switching of IgG isotypes, including IgG4. Thus, we immunohistochemically examined the number of Tfh in GCs in both TAFRO- and TAFRO+ iMCD. The number of Tfh was significantly decreased in TAFRO- iMCD (n = 9) and was further decreased in TAFRO+ iMCD (n = 18) in comparison to non-specific lymphadenopathy (n = 6) and IgG4-related disease (n = 4). These results suggest that decreased Tfh may be one etiology of iMCD.

Is TAFRO syndrome a subtype of idiopathic multicentric Castleman disease?

Castleman disease (CD) is a rare lymphoproliferative disorder that can be unicentric or multicentric. Multicentric CD (MCD) is further subdivided into human herpesvirus type-8-associated, POEMS syndrome-associated, and idiopathic (iMCD). TAFRO syndrome is a newly identified disorder of unknown etiology characterized by thrombocytopenia, anasarca, fever, reticulin myelofibrosis, renal dysfunction, and organomegaly. The TAFRO syndrome is sometimes regarded as a subtype of iMCD (TAFRO-iMCD), whereas iMCD without TAFRO syndrome is considered "not otherwise specified" (iMCD-NOS). However, a proportion of patients with TAFRO syndrome have been diagnosed without lymph node biopsies (TAFRO syndrome without proven iMCD; TAFRO-w/op-iMCD). To clarify the clinical features of iMCD-NOS, TAFRO-iMCD, and TAFRO-w/op-iMCD, we retrospectively analyzed 220 patients extracted from the database of the Multicenter Collaborative Retrospective Study for Establishing the Concept of TAFRO Syndrome. The patients included 87 with iMCD-NOS, 63 with TAFRO-iMCD, and 19 with TAFRO-w/op-iMCD. Patients in all three groups exhibited anemia, hypoalbuminemia, and elevated serum C-reactive protein and interleukin-6 levels. No significant differences in clinical, laboratory, and prognostic features were noted between the TAFRO-iMCD, and TAFRO-w/op-iMCD groups. However, the iMCD-NOS group exhibited polyclonal hyper-γ-globulinemia. The five-year survival rates of patients in the iMCD-NOS and TAFRO-involved groups were 100% and 66.5%, respectively (dropping markedly during the first few months in the latter). The iMCD-NOS and the TAFRO-iMCD samples typically showed plasma cell and mixed-type histologies, respectively. Thus, iMCD can be classified into two distinct subtypes, iMCD-NOS and TAFRO-iMCD. As such, TAFRO-iMCD and TAFRO-w/op-iMCD may be considered the same entity, requiring prompt diagnosis and intensive care.

An extranodal histopathological analysis of idiopathic multicentric Castleman disease with and without TAFRO syndrome.

Thrombocytopenia, anasarca, fever, renal failure or reticulin fibrosis, and organomegaly (TAFRO) syndrome, a poor prognostic clinical condition showing similar histopathological findings to idiopathic multicentric Castleman disease (iMCD), has been reported in Japan. In our previous report, a clinicopathological analysis was performed on 70 nodal cases of iMCD with/without TAFRO. iMCD is classified into three types based on histopathology: (i) plasmacytic (PC), (ii) mixed, and (iii) hypervascular (hyperV). In this report, extranodal histopathological changes of iMCD with/without TAFRO were analyzed. Regarding the kidney pathology, we observed the proliferation of mesangial cells with positive staining of interleukin-6 (IL-6), consistent with membranoproliferative glomerulonephritis, in two cases of iMCD with TAFRO. The number of megakaryocytes per high-powered fields was not significantly different between iMCD cases with and without TAFRO. In conclusion, extranodal lesions of iMCD with/without TAFRO showed various interesting histopathological findings. These lesions may therefore be related to the clinical condition of TAFRO. Obtaining further knowledge about TAFRO will require the observation of nodal as well as extranodal lesions.

The clinicopathological comparison among nodal cases of idiopathic multicentric Castleman disease with and without TAFRO syndrome.

Multicentric Castleman disease (MCD) is a systemic inflammatory disease potentially caused by an increase in the serum interleukin-6 (IL-6) level. Idiopathic MCD (iMCD) is histopathologically classified into three types: plasmacytic (PC), mixed, and hypervascular (hyperV) types. Recently, a unique clinical phenotype with a poor prognosis overlap with iMCD, thrombocytopenia, anasarca, fever, renal failure or reticulin fibrosis, and organomegaly (TAFRO syndrome), has been reported from Japan, but its detailed clinicopathological features remain unclear. In this study, we performed a clinicopathological analysis of 70 nodal cases of iMCD with and without TAFRO syndrome (n = 37 versus n = 33). Compared with iMCD without TAFRO, iMCD with TAFRO showed more atrophic lymphoid follicles (LF), greater distances between follicles, increased glomeruloid vascular proliferation within the germinal center, and increased follicular dendritic cells. In addition, the hyperV type in particular demonstrated severe atrophic LF and interfollicular vascular proliferation. Among the mixed-type cases, the serum IL-6 levels in iMCD with TAFRO were significantly higher than those in iMCD without TAFRO. Furthermore, compared to iMCD without TAFRO, the numbers of immunoglobulin G4 (IgG4)-positive and CD38-positive plasma cells were significantly decreased in iMCD with TAFRO.

Elevated serum interferon γ-induced protein 10 kDa is associated with TAFRO syndrome.

Multicentric Castleman disease (MCD) is a heterogeneous lymphoproliferative disorder. It is characterized by inflammatory symptoms, and interleukin (IL)-6 contributes to the disease pathogenesis. Human herpesvirus 8 (HHV-8) often drives hypercytokinemia in MCD, although the etiology of HHV-8-negative MCD is idiopathic (iMCD). A distinct subtype of iMCD that shares a constellation of clinical features including thrombocytopenia (T), anasarca (A), fever (F), reticulin fibrosis (R), and organomegaly (O) has been reported as TAFRO-iMCD, however the differences in cytokine profiles between TAFRO-iMCD and iMCD have not been established. We retrospectively compared levels of serum interferon γ-induced protein 10 kDa (IP-10), platelet-derived growth factor (PDGF)-AA, interleukin (IL)-10, and other cytokines between 11 cases of TAFRO-iMCD, 6 cases of plasma cell type iMCD, and 21 healthy controls. During flare-ups, patients with TAFRO-iMCD had significantly higher serum IP-10 and tended to have lower PDGF-AA levels than the other 2 groups. In addition, serum IL-10, IL-23, and vascular endothelial growth factor-A were elevated in both TAFRO-iMCD and iMCD. Elevated serum IP-10 is associated with inflammatory diseases including infectious diseases. There was a strong correlation between high serum IP-10 and the presence of TAFRO-iMCD, suggesting that IP-10 might be involved in the pathogenesis of TAFRO-iMCD.

Proposed diagnostic criteria, disease severity classification and treatment strategy for TAFRO syndrome, 2015 version.

TAFRO syndrome is a systemic inflammatory disorder characterized by thrombocytopenia, anasarca including pleural effusion and ascites, fever, renal insufficiency, and organomegaly including hepatosplenomegaly and lymphadenopathy. Its onset may be acute or sub-acute, but its etiology is undetermined. Although several clinical and pathological characteristics of TAFRO syndrome resemble those of multicentric Castleman disease (MCD), other specific features can differentiate between them. Some TAFRO syndrome patients have been successfully treated with glucocorticoids and/or immunosuppressants, including cyclosporin A, tocilizumab and rituximab, whereas others are refractory to treatment, and eventually succumb to the disease. Early and reliable diagnoses and early treatments with appropriate agents are essential to enhancing patient survival. The present article reports the 2015 updated diagnostic criteria, disease severity classification and treatment strategy for TAFRO syndrome, as formulated by Japanese research teams. These criteria and classification have been applied and retrospectively validated on clinicopathologic data of 28 patients with this and similar conditions (e.g. MCD with serositis and thrombocytopenia).

Clinicopathologic analysis of TAFRO syndrome demonstrates a distinct subtype of HHV-8-negative multicentric Castleman disease.

Multicentric Castleman disease (MCD) describes a heterogeneous group of disorders involving systemic inflammation, characteristic lymph node histopathology, and multi-organ dysfunction because of pathologic hypercytokinemia. Whereas Human Herpes Virus-8 (HHV-8) drives the hypercytokinemia in a cohort of immunocompromised patients, the etiology of HHV-8-negative MCD is idiopathic (iMCD). Recently, a limited series of iMCD cases in Japan sharing a constellation of clinical features, including thrombocytopenia (T), anasarca (A), fever (F), reticulin fibrosis (R), and organomegaly (O) has been described as TAFRO syndrome. Herein, we report clinicopathological findings on 25 patients (14 males and 11 females; 23 Japanese-born and two US-born), the largest TAFRO syndrome case series, including the first report of cases from the USA. The median age of onset was 50 years old (range: 23-72). The frequency of each feature was as follows: thrombocytopenia (21/25), anasarca (24/25), fever (21/25), organomegaly (25/25), and reticulin fibrosis (13/16). These patients frequently demonstrated abdominal pain, elevated serum alkaline phosphatase levels, and acute kidney failure. Surprisingly, none of the cases demonstrated marked hypergammoglobulinemia, which is frequently reported in iMCD. Lymph node biopsies revealed atrophic germinal centers with enlarged nuclei of endothelial cells and proliferation of endothelial venules in interfollicular zone. 23 of 25 cases were treated initially with corticosteroids; 12 patients responded poorly and required further therapy. Three patients died during the observation period (median: 9 months) because of disease progression or infections. TAFRO syndrome is a unique subtype of iMCD that demonstrates characteristic clinicopathological findings. Further study to clarify prognosis, pathophysiology, and appropriate treatment is needed.

Castleman-Kojima disease (TAFRO syndrome) : a novel systemic inflammatory disease characterized by a constellation of symptoms, namely, thrombocytopenia, ascites (anasarca), microcytic anemia, myelofibrosis, renal dysfunction, and organomegaly : a status report and summary of Fukushima (6 June, 2012) and Nagoya meetings (22 September, 2012).

Recently, a unique clinicopathologic variant of multicentric Castleman's disease (MCD) has been identified in Japan. This disease is characterized by a constellation of symptoms, as listed in the title, and multiple lymphadenopathy of mild degree with a pathologic diagnosis of atypical CD, often posing diagnostic and therapeutic problems for pathologists and hematologists, respectively. These findings suggest that this disease represents a novel clinical entity belonging to systemic inflammatory disorders with a background of immunological abnormality beyond the ordinal spectrum of MCD. To define this disorder more clearly, Japanese participants presented clinicopathologic data at the Fukushima and Nagoya meetings. Many of the patients presented by the participants were significantly accompanied by a combination of thrombocytopenia, ascites (anasarca), pleural effusions, microcytic anemia, fever, myelofibrosis, renal dysfunction, and organomegaly (TAFRO). Multiple lymphadenopathies were generally of mild degree, less than 1.5 cm in diameter, and consistently featured the histopathology of mixed- or less hyaline vascular-type CD. Autoantibodies were often detected. However, this disease did not fulfill the diagnostic criteria for well-known autoimmune diseases including systemic lupus erythematosus. Castleman-Kojima disease and TAFRO syndrome (the favored clinical term) were proposed for this disease. The patients were sensitive to steroid and anti-interleukin-6 receptor antibody (tocilizumab), but some exhibited a deteriorated clinical course despite the treatment. The participants proposed a future nationwide survey and a Japanese consortium to facilitate further clinical and therapeutic studies of this novel disease. [J Clin Exp Hematop 53(1): 57-61, 2013].

Thrombocytopenia with reticulin fibrosis accompanied by fever, anasarca and hepatosplenomegaly : a clinical report of five cases.

We report five cases that presented with high fever, anasarca, hepatosplenomegaly and severe thrombocytopenia with reticulin fibrosis of the bone marrow. The constellation of symptoms is not compatible with any known disease, and we had difficulty in diagnosis and treatment. The age distribution was from 47 to 56 years, and two men and three women were affected. Two patients needed hemodialysis because of renal dysfunction and oliguria with massive pleural effusion. Laboratory examinations showed normal immunoglobulin levels and no monoclonal protein. None of them showed diagnostic autoantibodies for any autoimmune diseases. Histological examination of the liver in three patients and spleen in two showed non-specific findings. Lymphadenopathy was tiny and lymph node biopsy was carried out in only one case. Histologically, paracortical hyperplasia with vascular proliferation and atrophic germinal centers resembling hyaline-vascular-type Castleman's disease or POEMS syndrome were detected. Without a definitive diagnosis, treatment was started with cyclophosphamide, hydroxydaunorubicin, vincristine and prednisolone (CHOP) regimen in one patient, semi-pulse therapy with methyl-predonisolone in three and cyclosporin A in three. Two patients achieved complete remission, two were steroid-dependent and the remaining one died of multiple organ failure. These findings suggest that this disease may be a novel clinical entity belonging to systemic inflammatory disorder with a background of immunological abnormality or a unique variant of multicentric Castleman's disease. [J Clin Exp Hematop 53(1): 63-68, 2013].

[Successful treatment of acute promyelocytic leukemia complicated with autoimmune hepatitis-induced portal hypertension with all-trans retinoic acid].

A 35-year-old man admitted to the hospital for oral hemorrhage was diagnosed with acute promyelocytic leukemia (APL). Remission from APL was achieved by induction therapy with all-trans retinoic acid (ATRA); the PML/RARA fusion gene was not detected on PCR analysis. Despite complete molecular remission, severe persistent pancytopenia, massive ascites, and renal failure were observed. The liver surface appeared rough and irregular on computed tomographic images. On the basis of the liver biopsy results, we diagnosed his condition as portal hypertension due to autoimmune hepatitis. Indocyanine green test showed good residual function of the liver, and therefore, 2 courses of consolidation therapy were administered; chemotherapy was stopped because of severe pancytopenia due to portal hypertension. Instead of continuing the consolidation therapy, maintenance therapy involving 8 rounds of ATRA monotherapy (45 mg/m(2), days1∼14) was initiated. Portal hypertension did not progress further with this maintenance therapy and therefore it was continued. The patient has been in remission from APL ever since, and no relapses have occurred since the past 5 years. These results suggest that ATRA can be used for long-term therapy in such cases.

[Atypical myeloproliferative neoplasm with a small population of Philadelphia chromosome-positive clones in the bone marrow].

A 52-year-old woman presented with isolated thrombocytosis in 2003. After 5 years of observation under a tentative diagnosis of essential thrombocythemia (ET), she was referred to our hospital because of anemia and leukopenia. Bone marrow biopsy demonstrated increases of megakaryocytes and myelofibrosis, but splenomegaly was absent. A karyotype study of bone marrow detected t(9;22) (q34;q11.2) in 6 of the 20 metaphases studied. Peripheral blood neutrophil BCA-ABL fusion signals (FISH) were not detected. Because RT-PCR assay of bone marrow detected major-BCR-ABL mRNA (b3a2), treatment with imatinib (400 mg/day) was started. After transient thrombocytopenia, normalization of blood cell counts and improvement of myelofibrosis were achieved. JAK2 V617F mutation and M-BCR-ABL mRNA was negative in peripheral blood. Clinical and laboratory data suggest that this case represents a rare and atypical myeloproliferative neoplasm with BCR-ABL translocation restricted mainly to the megakaryocyte lineage.