Janice M. Hodnefield

SF3B1 mutations are prevalent in myelodysplastic syndromes with ring sideroblasts but do not hold independent prognostic value

SF3B1 mutations were recently reported in myelodysplastic syndromes (MDSs), especially in the presence of ring sideroblasts (RSs). We sought to define the interaction between SF3B1 mutations, morphology, karyotype, and prognosis in MDS with more than or equal to 15% RS (MDS-RS). We studied 107 patients with MDS-RS, including 48 with refractory anemia with RS (RARS), 43 with refractory cytopenia with multilineage dysplasia (RCMD)-RS, 11 with refractory anemia with excess blasts-1 (RAEB1)-RS, and 5 with RAEB2-RS. SF3B1 mutations were detected in 53 (∼ 50%) patients: 35 RARS (73%), 16 RCMD-RS (37%), and 2 RAEB1-RS (18%). In univariate analysis, the presence of SF3B1 mutations was associated with better overall (P < .01) and leukemia-free (P < .01) survival; however, in both instances, significance was completely accounted for by World Health Organization morphologic risk categorization. In other words, when RARS and RCMD-RS were analyzed separately, there was no additional prognostic value from the presence or absence of SF3B1 mutations.

Mayo prognostic model for WHO-defined chronic myelomonocytic leukemia: ASXL1 and spliceosome component mutations and outcomes

We evaluated the prognostic relevance of several clinical and laboratory parameters in 226 Mayo Clinic patients with chronic myelomonocytic leukemia (CMML): 152 (67%) males and median age 71 years. At a median follow-up of 15 months, 166 (73%) deaths and 33 (14.5%) leukemic transformations were documented. In univariate analysis, significant risk factors for survival included anemia, thrombocytopenia, increased levels of white blood cells, absolute neutrophils, absolute monocyte count (AMC), absolute lymphocytes, peripheral blood and bone marrow blasts, and presence of circulating immature myeloid cells (IMCs). Spliceosome component (P=0.4) and ASXL1 mutations (P=0.37) had no impact survival. On multivariable analysis, increased AMC (>10 × 109/l, relative risk (RR) 2.5, 95% confidence interval (CI) 1.7–3.8), presence of circulating IMC (RR 2.0, 95% CI 1.4–2.7), decreased hemoglobin (<10 g/dl, RR 1.6, 99% CI 1.2–2.2) and decreased platelet count (<100 × 109/l, RR 1.4, 99% CI 1.0–1.9) remained significant. Using these four risk factors, a new prognostic model for overall (high risk, RR 4.4, 95% CI 2.9–6.7; intermediate risk, RR 2.0, 95% CI 1.4–2.9) and leukemia-free survival (high risk, RR 4.9, 95% CI 1.9–12.8; intermediate risk, RR 2.6, 95% CI 1.1–5.9) performed better than other conventional risk models and was validated in an independent cohort of 268 CMML patients.

Differential prognostic effect of IDH1 versus IDH2 mutations in myelodysplastic syndromes: a Mayo Clinic Study of 277 patients

Unlike the case with acute myeloid leukemia, there is limited information on the prognostic impact of isocitrate dehydrogenase (IDH) mutations in myelodysplastic syndromes (MDS). In the current study of 277 patients with MDS, IDH mutations were detected in 34 (12%) cases: 26 IDH2 (all R140Q) and 8 IDH1 (6 R132S and 2 R132C). Mutational frequency was 4% (2 of 56) in refractory anemia with ring sideroblasts, 12% (16 of 130) in refractory cytopenia with multilineage dysplasia, 14% (2 of 14) in MDS-unclassifiable, 14% (6 of 42) in refractory anemia with excess blasts (RAEB)-1 and 23% (8 of 35) in RAEB-2. Normal karyotype was noted in all but one IDH1-mutated cases and 13 IDH2-mutated cases. Multivariable analysis identified presence of mutant IDH1 (P=0.0004; hazard ration 4.0, 95% confidence interval 1.9–8.8), revised International Prognostic Scoring System risk category (P<0.0001), and red cell transfusion need (P=0.002) as independent predictors of inferior survival. In a similar multivariable analysis, mutant IDH1 was the only variable associated with shortened leukemia-free survival (P=0.001; hazard ration 7.0, 95% confidence interval 2.3–20.8). The presence of IDH2R140Q did not affect the overall (P=0.54) or leukemia-free (P=0.81) survival. The current study suggests a powerful adverse prognostic effect for mutant IDH1 in MDS.

Spliceosome mutations involving SRSF2, SF3B1, and U2AF35 in chronic myelomonocytic leukemia: Prevalence, clinical correlates, and prognostic relevance

SRSF2, SF3B1, and U2AF35 (U2AF1) are the three most frequent genes involved with spliceosome mutations in myeloid malignancies. SF3B1 mutations are most frequent (~80%) in myelodysplastic syndromes (MDS) with ring sideroblasts (RS) but lack prognostic relevance. SRSF2 mutations are associated with shortened overall (OS) and leukemia‐free survival (LFS) in both MDS and myelofibrosis. In this study of 226 patients with chronic myelomonocytic leukemia (CMML), mutational frequencies were 40% for SRSF2 (all affecting P95), 6% for SF3B1 (primarily K700E) and 9% for U2AF35 (mostly S34F and Q157P/R). These mutations were mutually exclusive and 54% of the patients displayed at least one mutation. The three mutation groups were phenotypically similar, with the exception of higher RS% (P < 0.0001) in patients with SF3B1 mutations. At a median follow‐up of 15 months, 176 (78%) deaths and 32 (14%) leukemic transformations were documented. OS (median survivals of 17, 16, 17, and 20 months; P = 0.48) and LFS (leukemic transformation rates of 17, 13, 15, and 5%; P = 0.63) were similar among patients with none of the three mutations, SRSF2, SF3B1, or U2AF35 mutations, respectively. We conclude that SRSF2 is the most frequently mutated spliceosome gene in CMML but neither it nor SF3B1 or U2AF35 mutations are prognostically relevant. Am. J. Hematol. 88:201–206, 2013.

Predictive Value of Blood and Bone Marrow Flow Cytometry in B-Cell Lymphoma Classification: Comparative Analysis of Flow Cytometry and Tissue Biopsy in 252 Patients

OBJECTIVE To study the effectiveness of peripheral blood (PB) and bone marrow flow cytometric immunophenotyping (FCIP) in predicting the histologic B-cell lymphoma type. PATIENTS AND METHODS We studied the FCIP results and tissue histopathology from 252 patients with B-cell lymphoma seen at Mayo Clinics site in Rochester, MN, between January 1, 1997, and January 1, 2004, who had positive results on PB, bone marrow, or body fluid FCIP and a corresponding diagnostic tissue biopsy specimen. RESULTS Most of the B-cell lymphomas studied were low grade, with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma being most common. Flow cytometric immunophenotyping histogram analysis was more informative than tabulated percentage antigen positivity; surface immunoglobulin and CD20 staining intensity, CD5 and CD23 positivity, CD10 positivity, and the coexpression of CD11c/CD22 and CD103 were the most pertinent markers. Using these FCIP parameters and strict immunophenotypic definitions for CLL, mantle cell lymphoma (MCL), and hairy cell leukemia, we obtained greater than 95% specificity for each diagnosis. However, we encountered the following exceptions to standard paradigms of B-cell lymphoma-associated FCIP: (1) CD5 expression by disorders distinct from CLL and MCL, (2) lack of uniform CD5 positivity in some CLL and MCL cases, (3) absence of CD10 in approximately 50% of follicular lymphomas, and (4) expression of CD103 by occasional marginal zone lymphomas. CONCLUSION Stringent interpretation of PB and bone marrow FCIP results enables identification of certain B-cell lymphoma types. However, the observed exceptions to accepted immunophenotypic paradigms highlight the occasional phenotypic overlap among diseases and emphasize that a systematic approach to FCIP interpretations is key to providing clinically useful diagnostic information.

Monosomal karyotype in myelodysplastic syndromes, with or without monosomy 7 or 5, is prognostically worse than an otherwise complex karyotype

Monosomal karyotype (MK) refers to the presence of two or more distinct autosomal monosomies or a single monosomy associated with a structural abnormality. In acute myeloid leukemia, MK has been shown to be prognostically worse than an otherwise complex karyotype. The current study examines whether the same holds true for myelodysplastic syndromes (MDS). A total of 127 MDS patients (median age 70 years) with a complex karyotype were considered; 106 (83%) met the above-stipulated criteria for MK and 21 (17%) had a complex karyotype without monosomies. Survival was significantly inferior in patients with MK compared with those with a complex karyotype without monosomies (P=0.01; HR 1.9, 95% confidence interval (95% CI), 1.1–3.3). Multivariable analysis identified MK (P=0.002), advanced age (P=0.0004) and bone marrow blast percentage (0.04) as independent risk factors for survival. There was no difference in survival among MK patients further substratified by the presence or absence of monosomy 7 and/or monosomy 5. Although not statistically significant, leukemia-free survival was also worse with MK compared with complex karyotype without monosomies (P=0.09; HR 2.7, 95% CI 0.8–9.0). MK in MDS identifies a prognostically worse subgroup of patients with a complex karyotype, regardless of whether monosomy 7 or 5 is part of the MK component.

Primary myelodysplastic syndrome with normal cytogenetics: utility of 'FISH panel testing' and M-FISH.

The myelodysplastic syndromes (MDS) are a clinically heterogeneous group of hematologic disorders. Cytogenetic analysis is crucial as it can provide both diagnostic and prognostic information. Herein, 32 cytogenetically normal patients with primary MDS were analyzed both by multiple FISH probes on interphase nuclei (FISH panel testing) and by M-FISH (metaphase nuclei). One patient had a chromosome 13q-arm deletion, while the remaining 31 patients had normal results. These findings confirm standard cytogenetics as an excellent technique in identifying the common chromosomal abnormalities associated with MDS and suggest limited utility for either a FISH panel test or M-FISH in primary MDS.

Clonal cytogenetic abnormalities in bone marrow specimens without clear morphologic evidence of dysplasia: a form fruste of myelodysplasia?☆

Cytogenetic abnormalities suggestive of a myeloid disorder are occasionally observed in the bone marrow (BM) cells of patients with morphologically and immunohistochemically unremarkable marrow aspirates and biopsies. Between 1994 and 2000, 55 such patients were seen at our institution (34 men; median age of 66 years). The indications for BM sampling included unexplained cytopenias (31 patients), staging or follow-up of a lymphoproliferative disorder or a plasma cell dyscrasia (18 patients), or another miscellaneous reason (6 patients). Specific cytogenetic abnormalities included a 20q deletion or monosomy 20 (10 patients), a chromosome 7 deletion (8 patients), +8 (5 patients), del(5q) or a 5q translocation (4 patients), and del(13q) (2 patients). Eleven patients had a complex karyotype. As of January 2002, 23 of the 55 patients were dead; median follow-up for living patients is 20 months. Of the 23 dead patients, 1 died of acute myelogenous leukemia (AML) and 6 of complications related to cytopenias. This study provides support for obtaining cytogenetic studies in patients with unexplained cytopenias if a morphologic explanation for the cytopenias is lacking. Continued follow-up of this heterogeneous cohort and further studies of similar patients will more clearly define the disease processes and prognosis for this constellation of laboratory findings.

Evaluation of revised IPSS cytogenetic risk stratification and prognostic impact of monosomal karyotype in 783 patients with primary myelodysplastic syndromes.

Cytogenetic classification by the revised international prognostic scoring system (IPSS‐R) and the prognostic value of monosomal karyotype (MK) were assessed in 783 patients with primary myelodysplastic syndromes (MDS). At 22 months median follow‐up, 562 (72%) deaths were recorded. Percentages of patients with IPSS‐R “very good,” “good,” “intermediate,” “poor,” and “very poor” cytogenetic categories was 5, 63, 18, 4, and 10%, respectively. The corresponding median survivals were 21, 40, 24, 18, and 6.5 months and the inter‐group differences (good vs. very good/intermediate/poor vs. very poor; P < 0.01) or similarities (very good vs. intermediate vs. poor; P = 0.79) were not significantly modified in multivariable analysis. Results were similar when analysis was restricted to 602 patients managed by supportive care. MK adversely affected survival in both poor and very poor karyotype groups (P < 0.01). In conclusion, we were unable to confirm the prognostic superiority of IPSS‐R‐very good karyotype or prognostically distinguish between very good, intermediate and poor karyotypes. Furthermore, we show additional prognostic information from MK in poor/very poor karyotype. Am. J. Hematol. 88:690–693, 2013.

The significance of isolated Y chromosome loss in bone marrow metaphase cells from males over age 50 years

To further investigate the potential clinical significance of Y chromosome loss as the sole bone marrow karyotype change, we studied 161 Mayo Clinic male patients with 75% or more metaphase cells with Y loss, and correlated the percent Y loss with age and hematopathologic review. In patients with a lymphoproliferative or plasma cell disorder, the negligible proportion of bone marrow involvement cannot account for the observed high proportion of -Y cells. In males with myeloid disease, Y loss appears to often represent the abnormal myeloid clone, which may also harbor acquired genetic changes that are not observed by conventional cytogenetic analysis.