Jean E. Goasguen

Diagnosis and classification of myelodysplastic syndrome: International Working Group on Morphology of myelodysplastic syndrome (IWGM-MDS) consensus proposals for the definition and enumeration of myeloblasts and ring sideroblasts

This article details the proposals of the IWGM-MDS for the definition of myeloblasts, promyelocytes and ring side-roblasts in patients with myelodysplastic syndrome. The classification of myelodysplastic syndromes is based on the morphological criteria proposed by the French-American-British (FAB) and World Health Organization (WHO) groups. Accurate enumeration of blast cells, although essential for diagnosis of myelodysplastic syndrome and for assignment to prognostic groups, is often difficult, due to imprecise criteria for the morphological definition of blasts and promyelocytes. An International Working Group on Morphology of Myelodysplastic Syndrome (IWGM-MDS) of hematopathologists and hematologists expert in the field of myelodysplastic syndrome reviewed the morphological features of bone marrows from all subtypes of myelodysplastic syndrome and agreed on a set of recommendations, including recommendations for the definition and enumeration of blast cells and ring sideroblasts. It is recommended that (1) agranular or granular blast cells be defined (replacing the previous type I, II and III blasts), (2) dysplastic promyelocytes be distinguished from cytologically normal promyelocytes and from granular blast cells, (3) sufficient cells be counted to give a precise blast percentage, particularly at thresholds that are important for diagnosis or prognosis and (4) ring sideroblasts be defined as erythroblasts in which there are a minimum of 5 siderotic granules covering at least a third of the nuclear circumference. Clear definitions and a differential count of a sufficient number of cells is likely to improve precision in the diagnosis and classification of myelodysplastic syndrome. Recommendations should be applied in the context of the WHO classification.

Indolent course as a relatively frequent presentation in T‐prolymphocytic leukaemia

T‐prolymphocytic leukaemia (T‐PLL) is a rare disorder with a poor outcome. Presentation features were studied in 78 T‐PLL cases. Although 53 patients (group A) presented with typical progressive disease including rapidly increasing leucocytosis, 25 patients (group B) experienced an initial indolent clinical course with stable moderate leucocytosis. The morphology and antigenic profile of abnormal cells were similar in both groups, except for a lower incidence of CD45RO+ CD45RA− pattern in group B. A high incidence of inv(14)(q11;q32), t(14;14)(q11;q32) and i(8)(q10) chromosomal abnormalities were found in both groups. After an initial indolent phase (median 33 months; 6–103 months), 16 group B patients progressed to an aggressive stage with clinical and laboratory features similar to group A. Moreover, median survival after progression was short in both groups. In conclusion, T‐PLL may start as an indolent disease similar to that reported in ataxia telangectasia. In this rare genetic disorder, some patients develop stable T‐cell clones which progress toward T‐PLL‐like leukaemia. Moreover, ATM gene mutations have been reported in T‐PLL. Thus, both diseases are likely to be closely related.

Morphological evaluation of monocytes and their precursors

This study establishes morphological definitions so that monocytes, including immature monocytes, can be reliably separated from the spectrum of monocyte precursors. The monocyte is still the most difficult cell to identify with confidence in the peripheral blood or in the bone marrow in healthy individuals as well as in patients with infections, and in those with leukemic proliferations. The goal of this study was to establish morphological definitions so that monocytes, including immature monocytes, could be separated from the spectrum of monocyte precursors. Cells from peripheral blood or bone marrow were selected to provide a large panel of normal and leukemic cells at different maturational stages and were submitted to 5 experts, who had previously reached a consensus, on the basis of microscopy, in defining 4 subtypes: monoblast, promonocyte, immature monocyte, mature, monocyte. They achieved a good concordance rate of 76.6% and a high κ rate confirming that the criteria for defining the 4 subtypes could be applied consistently. It has now to be established whether these monocyte subtypes correlate with immunological or molecular markers and are clinically relevant.

Mature plasma cells as indicator of better prognosis in multiple myeloma. New methodology for the assessment of plasma cell morphology.

The relationship between plasmablastic cells and outcome in multiple myeloma (MM) has been established for nearly 15 years. But the assessment of these cells is not easy to perform and it allows the identification of only a small proportion of patients. We investigated the plasma cell morphology using a progressive evaluation of consecutive criteria: nucleolus, chromatin and nuclear-cellular ratio (N/C). The combination of these three items produces a subclassification where four cellular subtypes identify 93% of the plasma cells, and these subtypes are related to the outcome. The interest of this methodology is to be based on the mature plasma cells that are easier to identify than the plasmablastic cells. These new cell subtypes introduce a new classification for patients: Group 1 includes patients with at least 66% mature plasma cells (P000). Both Group 2 and 3 have less than 66% P000 and are separated by their degree of maturation (Proplasma I > or = Proplasma II + plasmablastic). The distinction of these three groups of patients is highly related to the prognosis (P < 10(-4)). These results have been confirmed on a second group of patients coming from a different institution. In conclusion, we propose a new methodology for the plasma cell evaluation in MM, that is based on the morphological criteria and that has the advantage of identifying an intermediate (30%) subgroup of patients with a prognostic significance.

Multifactorial Drug-Resistance Phenomenon in Acute Leukemias: Impact of P170-MDR1, LRP56 Protein, Glutathione-Transferases and Metallothionein Systems on Clinical Outcome

The multidrug resistance phenomenon can be observed in cases which do not express the P170 protein and these cases are suspected as having activated different resistance phenomena. Four phenomena were studied at the time of diagnosis in a series of 35 lymphoblastic and 25 myeloblastic acute (de novo) leukemias, by an immunocytochemical method. Two energetic drug transport processes were investigated: the classical MDR/P170 and the P110/LRP56 proteins, and two physiological detoxifying activities such as the glutathione transferases (GST alpha, mu, pi) and the metallothioneins (Mts). The results demonstrate that these phenomena are independent but their synergic activity can increase their impact on the outcome. P110/LRP56 positive cases demonstrated 48.8% complete remission (CR) rate compared to 71.4% for negative tests. When P170 and P110 were both positive or negative, the CR rates were 27.3% and 81.8% respectively (p = 0.0120), and survival curves were also different (p = 0.030). The CR rate in AML or ALL is weakly affected by GST pi, alpha or mu but relapses are more frequently observed for Positive-GST pi ALL (p = 0.0658). Patients with both P170 and GST pi positive reactions had a 53.3% CR rate compared to 78.9% for both negative reactions. Survival curves for these two groups were different. The CR rate in AMl was 100% for Mts positive and 43.7% for negative cases (p = 0.050), however the median survival was totally different for these two groups (p = 0.046). CR rates were 26.6% for patients who were P170 positive and Mts negative compared to 100% for P170 negative and Mts positive (p = 0.038) patients. Survival curves were also different (p = 0.0510). We conclude that these four mechanisms induce an independent drug resistance but their synergic action increase their impact on the outcome. The metallothioneins seem to have a major impact on the drug resistance phenomenon and its effect should be investigated with high priority, in the light of these results.

Proposal for refining the definition of dysgranulopoiesis in acute myeloid leukemia and myelodysplastic syndromes

Studies of morphology of myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML) refer to the definitions produced by the French-American-British (FAB) group and by the World Health Organization expert group. To clarify some points regarding the dysgranulopoiesis that are still unclear we analyzed a series of 98 neutrophils from MDS patients with regard to granularity, nuclear segmentation, the appearance of the chromatin, the presence of giant neutrophils, and the presence of nuclear chromatin extensions. We found that cells with at least 2/3 reduction of the content of granules, Pelger-like neutrophils, dysplastic non-Pelger cells, neutrophils with abnormal clumping of the chromatin, and macropolycytes could be recognized as dysplastic and included in the 10% count recommended by these two classifications. In addition, we suggest that neutrophils with more than 4 nuclear projections could be recognized as a relevant dysplastic feature.

Intratumoral consumption of indium-111-labeled platelets in a child with splenic hemangioma and thrombocytopenia.

The authors report Kasabach-Merritt syndrome (KMS) in a patient with thrombocytopenia and splenic hemangioma. A 13-month-old boy with a history of anemia, thrombocytopenia, and abdominal mass was admitted to the hospital. The scintigraphic studies showed that a large mass contiguous to the spleen was responsible for the platelet uptake. After partial splenectomy, the platelet count returned to normal. This report of KMS in a child with splenic hemangioma suggests that the scintigraphic studies are mandatory to confirm diagnosis. Indium-111-labeled platelets are useful in identifying hemangiomatous sequestration of platelets in patients with thrombocytopenia.

Erythrocyte spermine levels: a prognostic parameter in childhood common acute lymphoblastic leukemia.

Polyamines have been implicated to play a role in cell proliferation and in cancer development. Ninety percent of the circulating spermidine (Spd) and spermine (Spm) are transported by red blood cells (RBC). RBC Spd and Spm levels were prospectively determined in 63 unselected children with common acute lymphoblastic leukemia. The Spm and Spd levels were not correlated with white blood cell (WBC) count. On the basis of the polyamine levels it was possible to discriminate four groups with P < 10−3. In C1, C2, C3 and C4 group the Spm level was respectively 90 (39–597), 3.75 (1–7.45), 9.95 (2.9–12.6) and 17(6.3–33.8). The probability of relapse-free survival (RFS) of the 58 children who entered complete remission was 55% ± 9. For the groups C1 (n = 6), C2 (n = 16), C3 (n = 21) and C4 (n = 15) groups, the RFS was 25% ± 20, 73% ± 12, 73% ± 13 and 32% ± 13 respectively. For children with Spm levels <13/⩾13 nmol/8 × 109 RBC, event-free survival (EFS) was 54% ± 11/33% ± 10 and RFS was 64% ± 12/38% ± 11 respectively (P < 0.03, P < 0.005). our clinical study shows clearly that an rbc spermine level could be used as parameter of prognosis at the time of diagnosis, particularly for patients with intermediary wbc count.

LRP overexpression in monocytic lineage

The failure to chemotherapy is a multi factorial phenomenon and lung resistance protein (LRP) overexpression has already been discussed as implicated in drug resistance. But its role is still discussed. In 1996, we studied the expression of LRP and P170 (MDR) in a series of leukemias, at the time of diagnosis, by immunocytochemical (ICC) method. The observation of a strong and unusual expression of LRP in acute myeloid leukemia (AML) with monocytic component led us to test (for P170 and LRP) a new series of 47 AML with different FAB subtypes. The expression of LRP was scored from 1 to 5 in blast cells and monocytes separately. We demonstrate that LRP is not correlated with clinical outcome but is statistically related to monoblastic leukemias. Code 5 reaction was found in 10/13 M5 versus the other FAB subtypes (P<10(-3)). The strongest LRP overexpression was also found in chronic myelomonocytic leukemia (four cases), reactive monocytosis (three cases) and in a dendritic cell line. In conclusion, we report that LRP is rather a marker of monocytic lineage than a prognostic index for MDR and we suggest that detection of LRP by ICC could be an argument for the diagnosis of monoblastic and monocytic leukemias.

Dyserythropoiesis in the diagnosis of the myelodysplastic syndromes and other myeloid neoplasms: problem areas

An evaluation of the significance of specified dyserythropoietic features in suspected myelodysplastic syndrome (MDS) and acute myeloid leukaemia with erythroid dysplasia was made by means of evaluation of 100 electronic images of bone marrow erythroblasts from each of 20 subjects: 11 with a myeloid neoplasm, six with another condition that could cause erythroid dysplasia and three healthy controls. The evaluation was carried out independently by seven experienced haematologists/haematopathologists who were blinded to the diagnosis. The majority of the dyserythropoietic features listed in the World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues were validated, although karyorrhexis was found to be infrequent and lacking in specificity; multinuclearity and megaloblastosis were more often observed but also lacked specificity. Good majority agreement on the identification of dysplastic features was obtained. Despite this, it was demonstrated that a reliable diagnosis of MDS can often not be made on the basis of erythroid morphology alone. Interpretation of dyserythropoiesis must be carried out with full knowledge of other clinicopathological features and with a constant awareness of the other conditions that can be confused with MDS. An iron stain is essential, as cases with ring sideroblasts may otherwise not be recognised as having MDS.