Peripheral blood cytogenetic studies in hematological neoplasms: predictors of obtaining metaphases for analysis

Abstract

Peripheral blood (PB) is sometimes used in place of bone marrow (BM) for cytogenetic studies during the evaluation of hematologic malignancies. A total of 242 PB cytogenetic studies from adult patients were performed: clinical diagnosis was a myeloid neoplasm in 169 patients (70%), lymphoid or plasma cell neoplasm in 50 (21%), and a benign/reactive cytopenia or leukocytosis in 23 (9%). PB cytogenetic studies resulted in at least two analyzable metaphases in 142 of the 242 study cases (59%); in univariate analysis, this was predicted by the specific clinical diagnosis (P < 0.0001), presence and degree of circulating myeloid progenitor cells or blasts of any lineage (P < 0.0001), higher leukocyte count (P < 0.001), lower platelet count (P = 0.003), lower hemoglobin level (P = 0.002), and presence of palpable splenomegaly (P = 0.002). In multivariable analysis, only the presence of circulating myeloid progenitor cells or blasts sustained significance and this was consistent with the high yield rates seen in primary myelofibrosis (PMF) (80%), post-PV/ET PMF (85%), acute myeloid leukemia (76%), and acute lymphoblastic leukemia (80%) in contrast with the low rates seen in ET (0%) and PV (2%). In 104 cases, BM cytogenetic studies were performed within 1 month of the PB cytogenetic studies; an abnormal BM cytogenetic finding was another independent predictor of a successful PB study (P = 0.002). PB cytogenetic studies are most appropriate in diseases of adults characterized by presence of circulating myeloid progenitors or blasts; the yield otherwise is too small to be cost-effective.

Karyotype complements the International Prognostic Scoring System for primary myelofibrosis

“…Karyotype in PMF has not gotten the attention it deserves because of the relative difficulty in obtaining adequate bone marrow specimen for cytogenetic analysis. However, peripheral blood can effectively be used in cases of ‘dry tap’ or otherwise suboptimal bone marrow studies (23, 24). Our observations as well as those of the IWG‐MRT who developed the IPSS for PMF confirm the additional prognostic value of karyotype.…”

Bone marrow evaluation for diagnosis and monitoring of acute myeloid leukemia

“…Similar findings were demonstrated by the study of Hussein et al, in which patients with high numbers of circulating blasts (at least 0.1 × 10 9 cells/L) were likely to have successful peripheral blood karyotype (90% success rate or higher). 13 In AML patients specifically, peripheral blood karyotyping produced successful metaphases in 32 out of 42 patients (76%). 13 Conventional karyotypeing with chromosome banding is the current standard in the diagnosis and work-up of a patient with AML, and several AML entities are defined by in the WHO classification by their recurrent karyotypic abnormalities.…”

“…13 In AML patients specifically, peripheral blood karyotyping produced successful metaphases in 32 out of 42 patients (76%). 13 Conventional karyotypeing with chromosome banding is the current standard in the diagnosis and work-up of a patient with AML, and several AML entities are defined by in the WHO classification by their recurrent karyotypic abnormalities. 1,3 It is possible that next generation sequencing approaches will make conventional chromosomal banding redundant in the future.…”

Correlation between peripheral blood and bone marrow regarding FLT3-ITD and NPM1 mutational status in patients with acute myeloid leukemia

“…9 Hussein et al studied the feasibility of using PB in place of BM for cytogenetic studies during the evaluation of hematologic malignancies (42 of 242 were AML patients). 10 They found cytogenetic studies were successfully performed using PB in 58% of the cases, and this was 76% in AML patients. On multivariate analysis, only progenitor cells/blast and BM chromosome abnormality predicted success in obtaining metaphases from PB.…”