Simultaneous Occurrence of Monoclonal Gammopathy and Acute Secondary Leukemia with Overexpression of P-Glycoprotein

Development of a transient monoclonal gammopathy after chemotherapy in a patient with biphenotypic acute leukemia

The development of a IgGk monoclonal gammopathy after a phase of bone marrow aplasia following chemotherapy is described in a patient suffering from biphenotypic acute leukemia (BAL). Paraprotein was followed by the relapse of the disease and disappeared during a further chemotherapy. Paraprotein could have been caused by an additional chemotherapy-induced genetic mutation or by a dysfunction in T-B cooperation observed in the phase of reconstitution of the immune system after medullar aplasia.

P-glycoprotein expression in de novo acute myeloid leukemia

Detection of the multidrug resistance P-glycoprotein (PGP) phenotype was performed at the time of diagnosis in 223 patients with acute myeloid leukemia (AML) by flow cytometry using C219 Monoclonal Antibody (MoAb). On the other hand, JSB1 MoAb was tested in 173 of these samples. At onset, PGP was detected in 57.4% of cases with C219 and 75.9% of cases with JSB1. There was no correlation between PGP expression and sex, age, marrow blast percentage or extramedullary disease. On the contrary, strict correlations were noted either between C219 negativity and FAB M3 subtype or between C219 positivity and FAB M5 group (P = 0.003). Significant correlation was found between PGP phenotype and CD7, as 143 of 223 samples had similar patterns of staining with C219 (P < 0.0001). Finally, there was a close relationship between C219 and JSB1 positivity: all the C219+ cases were positive for JSB1 (P < 0.0001). Concerning the karyotype, most patients with monosomy or del (7) were MDR positive; on the other hand, most patients with t(8;21) or t(15;17) were MDR negative. Rh123 accumulation studies showed a significant decrease of mean fluorescence intensities both in C219 and in JSB1 positive cases in comparison with PGP negative ones (P < 0.001). A significant decrease of remission induction rates (CR) was highlighted both between C219+ and C219- and between JSB1+ and JSB1- cases (32.1% v 62.1% and 32.6% v 73.8%, respectively, with P < 0.0001). The overall survival and the remission duration (CCR) were significantly shorter both in C219+ and in JSB1+ patients with no relationship to age. Furthermore, a higher rate of early relapses was noted among MDR+ when compared with MDR- patients both for C219+ and JSB1+ cases. The combination (C219- JSB1+) identified a subset of patients with an intermediate prognosis. On multivariate analysis, C219 and JSB1 were confirmed to be independent prognostic factors for achievement of CR, overall survival and CCR. In conclusion, the assessment of MDR phenotype by flow cytometry is a crucial prognostic factor of treatment outcome in AML.

Intensive treatment of patients age 60 years and older with de novo acute myeloid leukemia: analysis of prognostic factors

BACKGROUND

This study aimed to define pre-treatment parameters with prognostic significance in elderly patients with de novo acute myeloid leukemia (AML) who were treated with aggressive regimens.

METHODS

We analyzed, retrospectively, the clinical and laboratory features of 159 consecutive patients age >60 years with AML. Ninety-two patients presenting as de novo AML were considered suitable for aggressive chemotherapy according to inclusion criteria not different from those commonly used for younger adults. They belonged to all of the French-American-British classification types except M3, and their median age was 67 years (range: 60-79). Antileukemic treatment consisted of 1 of 3 sequential protocols adopted at the S. Eugenio University Hospital of Rome between 1987 and 1993. The three therapeutic groups were similar in number and presenting characteristics. In addition to arabinosylcytosine, induction schedules included mitoxantrone (Groups I and II) or daunorubicin (Group III), and etoposide (Groups I and III). Once in complete remission (CR), patients were consolidated with two other courses of chemotherapy using reduced dosages of the same drugs given during induction.

RESULTS

Induction treatment achieved a 52.2% CR rate, with median remission duration and event free survival (EFS) of 35 and 27 weeks, respectively. Because no significant differences between the results of the three therapeutic groups were observed, all cases were pooled to evaluate the prognostic factors. In univariate analysis, the only presenting characteristic significantly associated with failure of induction treatment was age >67 years (P=0.007). Factors associated with an increased likelihood of shorter remission duration were CD7 expression on leukemic cells (P=0.007) and an abnormal karyotype (P=0.010; those predicting shorter EFS were a chromosomal status other than normal (P=0.002) and detection of CD14 antigen (P=0.008). Logistic regression results identified age and CD14 expression as the variables with independent prognostic impact on CR achievement. In a stepwise proportional hazards general linear model, CD7 and karyotype retained their predictive value regarding remission duration, whereas the karyotypic pattern at diagnosis and CD14 antigen expression were the most important determinants of EFS, with age showing a borderline statistical value. A simple "risk factor score" was developed that would allow for stratification of patients into prognostic groups.

CONCLUSIONS

Cytogenetic analysis and immunophenotyping might help to select elderly patients with AML who have little benefit from current therapeutic strategies and with whom new approaches might be experimented.

CD7 expression in acute myeloid leukemia

The clinical significance of the expression of CD7 antigen on the blasts of 207 consecutive patients with de novo acute myeloid leukemia (AML) was evaluated. For this purpose, fifty-three CD7+ patients (23 females and 30 males; mean age 52 years) were analyzed and classified into the following subtypes according to French-American-British (FAB) classification: 7 M0, 13 M1, 9 M2, 1 M3, 9 M4, 14 M5. Immunophenotypic studies were carried out by flow cytometry and blast cells were selected on the basis of forward light scatter gating and pan-myeloid marker, either CD13 or CD33. All the CD7+ patients were negative for surface CD3 and T-cell-receptor (TCR) molecules. We found no correlation between CD7 expression and sex, age, hepatosplenomegaly and/or central nervous system involvement. The immaturity of CD7+ leukemic cells was supported by the high expression of CD34 (P = 0.001). CD7 positivity was significantly associated with a white blood cell count (WBC) greater than 100 x 10(9)/L (P = 0.003). P-Glycoprotein (P-170) expression was also evaluated in 135 patients by a flow-cytometric assay: there was a close relationship between CD7 and P-170 positivity (P < 0.001). For remission induction, all patients received therapeutic regimens routinely used for AML. The complete remission (CR) rate was significantly lower in CD7+ cases (32% vs 74%, P = 0.001). The overall survival and disease free survival rate of CD7+ AML was lower than those of CD7- patients (P < 0.001 and = 0.002, respectively). CD7+ AML with coexpression of CD14 had a particularly unfavourable response and prognosis in comparison with CD7+ patients without CD14.(ABSTRACT TRUNCATED AT 250 WORDS)

Minimally differentiated acute myeloid leukaemia (AML-M0): cytochemical, immunophenotypic and cytogenetic analysis of 19 cases

We describe our experience in the identification of 19 cases of AML-M0 categorized among 200 consecutive AML cases. Leukaemic cells from our cases were morphologically marked by agranular basophilic cytoplasm, finely dispersed chromatin and prominent nucleoli. In two cases heavily vacuolated and monocytoid-shaped blasts were also observed. Cytochemistry (MPO, SBB, alpha ANAE, alpha NBE, NASDCAE, AP, PAS) was negative in 14 cases, five cases expressing a very faint cytoplasmic positivity for alpha NBE (not exceeding 30% of the blasts) and alpha ANAE (not exceeding 41%) which was sodium fluoride resistant. In these five cases other monocytic markers (e.g. CD14) were not in favour of myelomonocytic differentiation. All the cases were anti-MPO positive at frequency > 10%. Phenotypic analysis also revealed myeloid features with all the patients having at least one myeloid antigen (CD13, CD33, CD15), Tdt was expressed in nine cases and CD7 in six cases. All cases but one were positive for CD34. Cytogenetic analysis, performed in 16 cases, showed no adequate growth in two cases and no consistent abnormality in four; among the remaining 10 cases no consistent abnormality was observed, the most common finding was trisomy 8 (two cases) and 4 (two cases) and aberrations of chromosomes 2, 3, 5, 7, 9, 12 and 21. No cases of (t9;22), Ph chromosome were observed. Interestingly three out of five patients with faint alpha NBE/alpha ANAE positivity relapsed as typical M4 (one case) or M5a (two cases).