Myeloperoxidase-deficient polymorphonuclear leucocytes. Longitudinal study during the preremission — and the remission phase in acute myeloid leukaemia

Summary Serial determinations of MPO and NAP activities in granulocytes were performed during the preremission phase and the remission phase in patients with AML. Of 18 patients examined during the preremission period, 9 showed an increased number of MPO deficient PMN. Complete remission was attained in 4 of these, in 3 the number of abnormal granulocytes changed to normal 7, 7 and 14 days before and in 1 simultaneously with the attainment of complete remission. In the other patients no changes in granulocyte MPO activity occurred during the preremission period.All 20 patients examined during complete remission showed a normal MPO activity in granulocytes. Of eight patients, who at diagnosis had shown abnormal granulocyte MPO activity, three developed relapse. In two of these, an increased number of MPO deficient PMN reappeared two and eight months prior to and in one simultaneous with clinical and laboratory suspicion of relapse. A statistically significant relation between low NAP scores and an increased number of MPO deficient PMN was found (P=0.011).Serial determinations of MPO activities in PMN, although restricted to cases of AML with initially abnormal values, may prove helpful in predicting achievement of complete remission and may furthermore prove to be useful as an indicator of early relapse.Abbreviations AML acute myeloid leukaemia - CR complete remission - MPO myeloperoxidase - NAP neutrophil alkaline phosphatase - PMN polymorphonuclear leucocytes     

Myeloperoxidase-deficient polymorphonuclear leucocytes. (I) Incidence in untreated myeloid leukaemia, lymphoid leukaemia and normal humans

Neutrophil myeloperoxidase (MPO) activity was analysed semi-quantitatively both by (i) MPO-scoring of polymorphonuclear leucocytes (PMN) and (ii) counting the MPO-deficient PMN (PMN lacking MPO) in 164 subjects (60 cases of leukaemia and 104 normal humans). The scoring method showed that 10 out of 21 (48%) cases of acute myeloid leukaemia (AML), 2 out of 10 (20%) cases of chronic myeloid leukaemia (CML), 0 out of 29 cases of lymphoid leukaemia (ALL + CLL), and 1 out of 104 normal humans had decreased MPO scores. These figures correlated well with the more simple counting of PMN lacking MPO in the same groups: 8 out of 21 (37%) cases of AML, 6 out of 10 (60%) cases of CML and 0 out of 29 cases of lymphoid leukaemia showing more than 4% PMN lacking MPO. In cases of otherwise unclassifiable acute leukaemia, a decreased MPO score and an increased number of MPO-deficient PMN suggests the diagnosis of AML and not ALL. Counting the number of PMN lacking MPO was found to be a time-saving and even more reliable method than the semiquantitative scoring of MPO activity in PMN.     

Myeloperoxidase-deficient polymorphonuclear leucocytes. (IV): Relation to FAB-classification in acute myeloid leukaemia

In 148 consecutive cases of untreated acute myeloid leukaemia (AML) the relation between an increased number of myeloperoxidase (MPO)-deficient polymorphonuclear leucocytes (PMN) and a classification modified after the proposals outlined by the French-American-British Co-operative Group, the FAB classification, was investigated. In 22 cases with minimal granulocytic component, 8 M5, 13 M6, 1 M7, no one (0%) showed an increased number of MPO-deficient PMN. In 3 (13%) of 23 cases with slight granulocytic component, 3 M0, 20 M1, and in 49 (57%) of 86 cases with granulocytic differentiation (53 M2, 1 M3, 32 M4), an increased number was demonstrated. This difference was statistically significant at a high level (P less than 0.0001). The number of MPO-deficient PMN could not be estimated in 15 cases of AML and 2 additional cases were mixed leukaemias. It is concluded that an increased number of MPO-deficient PMN in acute leukaemia speaks in favour not only of AML, but suggests the diagnosis of subtypes with some granulocytic component, most likely M1, M2, M3 or M4. Furthermore, the results support the concept that in AML at least some of the mature myeloid cells may be involved in the leukaemic process.     

Myeloperoxidase-deficient polymorphonuclear leucocytes (IV): Relation to FAB-classification in acute myeloid leukaemia

In 148 consecutive cases of untreated acute myeloid leukaemia (AML) the relation between an increased number of myeloperoxidase (MPO)-deficient polymorphonuclear leucocytes (PMN) and a classification modified after the proposals outlined by the French-American-British Co-operative Group, the FAB classification, was investigated. In 22 cases with minimal granulocytic component, 8 M₅, 13 M₆, 1 M₇, no one (0%) showed an increased number of MPO-deficient PMN. In 3 (13 %) of 23 cases with slight granulocytic component, 3 M₀, 20 M₁, and in 49 (57%) of 86 cases with granulocytic differentiation (53 M₂, 1 M₃, 32 M₄), an increased number was demonstrated. This difference was statistically significant at a high level (p < 0.0001). The number of MPO-deficient PMN could not be estimated in 15 cases of AML and 2 additional cases were mixed leukaemias. It is concluded that an increased number of MPO-deficient PMN in acute leukaemia speaks in favour not only of AML, but suggests the diagnosis of subtypes with some granulocytic component, most likely M₁, M₂, M₃ or M₄. Furthermore, the results support the concept that in AML at least some of the mature myeloid cells may be involved in the leukaemic process.     

Myeloperoxidase-deficient polymorphonuclear leucocytes (III): Relation to incidence of infection in acute myeloid leukaemia

In 74 cases of acute myeloid leukaemia (AML) the relation between pretreatment myeloperoxidase (MPO) activity in polymorphonuclear leucocytes (PMN) and the incidence of infection in the preremission phase of the disease was investigated retrospectively. 36 patients had abnormal numbers (greater than 4%) of MPO-deficient PMN and 38 had normal numbers. In the first group more patients experienced fever attacks, more showed an infectious focus and an aetiological cause was demonstrated more frequently than among patients in the second group. This difference was statistically significant (P less than 0.01). Furthermore, the patients in the first group experienced more fever attacks, showed more infectious focus and had infectious microorganisms demonstrated in more febrile episodes than patients in the second group (P less than 0.01). The differences were not explained by differences in the incidences of neutropenia or other parameters investigated. It is concluded that decreased MPO activity in PMN from AML patients may contribute to the increased susceptibility to infections and that in the preremission phase of the disease it may account for approximately 15% of the infections.     

Myeloperoxidase-deficient polymorphonuclear leucocytes (VII): Incidence in untreated myeloproliferative disorders

In 98 patients with chronic myeloproliferative disorders (45 chr. myeloid leukaemia (CML), 19 myelofibrosis primaria (MP), 28 polycythaemia vera (PV) and 6 idiopathic thrombocythaemia (IT)) the incidences of increased numbers of MPO-deficient polymorphonuclear (PMN) were 60% in CML, 32% in MP, 7% in PV and 0% in IT patients. The CML figure differed significantly from the others (p less than 0.001). This study confirms the finding of low NAP scores in CML compared to normal or high NAP scores in the other groups of the myeloproliferative syndrome. The incidences of increased numbers of MPO-deficient PMN in this study are comparable to those found in the primary myelodysplastic syndromes and in acute myeloid leukaemia. The finding supports the view that some of the CML cases and may be other cases of the chronic myeloproliferative disorders may be fundamentally the same disease as in primary myelodysplastic syndromes and in acute myeloid leukaemias.     

Spontaneous remission in acute myeloid leukaemia

A summary of the literature of adult patients with acute myeloid leukaemia (AML) who have undergone spontaneous remission (SR) is presented together with a report of a patient whose SR was accompanied by cytogenetic remission. There are less than 20 reports of SR since the 1980s. SR is by no means synonymous with cure, since the average duration of the remission is only 7·1±9·2 months. Neither infections nor transfusions are absolute requirements of SR.     

Myeloperoxidase-deficient polymorphonuclear leucocytes (VI): Relation to cytogenetic abnormalities in primary myelodysplastic syndromes

Relations between cytogenetic status, FAB-classification and an abnormal subpopulation of myeloperoxidase (MPO)-deficient polymorphonuclears (PMN) in 45 patients with myelodysplastic syndrome (MDS) are reported. Clonal abnormalities were demonstrated in 85% of the patients, with a lower incidence in the RA+ group (refractory anaemia with ring sideroblasts) compared to the others (p = 0.004). In 12 patients a spontaneous progression in cytogenetic aberrations occurred and in 7 of these (60%) a simultaneous progression in FAB-subtype was seen. The appearance of MPO-deficient PMNs was observed in 6 of these patients (55%). A progression in FAB-subtype was noted in further 4 patients and 2 additional patients developed MPO-deficient PMNs. Only one sufficient cytogenetic investigation was available in these patients. Thus 100% of the fully studied patients showed progression in cytogenetic abnormalities when a progression in FAB-subtype or a development of MPO-deficient PMNs was seen. 3 (49%) of the 8 patients developing MPO-deficient PMNs too showed a progression in FAB-subtype. Although no significant correlation to specific categories of structural aberrations or abnormalities in specific chromosome pairs could be demonstrated, clonal cytogenetic aberrations seem to be involved when the disease progresses and when MPO-deficient PMN develop.     

Isolated gingival relapse in acute myeloid leukaemia

A 47-yr-old man with acute myeloid leukaemia had been in complete remission for 18 months when he developed a gingival tumour. Histological examination revealed leukaemic infiltrate and, at this stage, no other signs of relapse could be demonstrated. Chemotherapy and local radiotherapy resulted in the disappearance of the mass; however, histological abnormalities persisted. First relapse of acute myeloid leukaemia presenting as a gingival tumour has not been previously reported.     

Serum enzyme concentrations in untreated acute myeloid leukaemia

Summary Serum concentrations of lactate dehydrogenase (LDH), -hydroxybutyrate dehydrogenase (HBD), phosphohexose isomerase (PHI), leucine aminopeptidase (LAP), -glucuronidase (-gluc) and angiotensin-converting enzyme (ACE), were measured in 107 cases of untreated acute myeloid leukaemia which were classified by morphological, immunological and cytochemical criteria. The results show that serum LDH was increased in most cases, irrespective of leukaemic subtype, serum PHI and LAP were significantly higher in monocytic variants and serum -gluc and ACE levels were generally within normal limits. In addition, significant (p<0.05) relationships were found between serum LDH, PHI, LAP and -gluc concentrations and the numbers of circulating leucocytes.     

Donor lymphocyte infusion induced molecular remission in relapse of acute myeloid leukaemia after allogeneic bone marrow transplantation.

Donor lymphocyte infusion (DLI) has been used successfully to induce remissions in relapse of acute myeloid leukaemia (AML) after bone marrow transplantation (BMT), but molecular eradication of leukaemia has rarely been documented. A patient with AML-M4Eo relapsed after HLA-identical sibling BMT in first complete remission (CR). Cytogenetic and molecular genetic investigations confirmed inv(16) and CBFbeta/MYH11 fusion characteristic of M4Eo. A second remission was obtained with chemotherapy. Full donor chimerism was demonstrated by fluorescence in situ hybridisation. However, molecular evidence of minimal residual disease still persisted, and donor lymphocyte infusion (DLI) was administered. This resulted in molecular eradication, and the patient remained in clinical and molecular remission 16 months from DLI. Our observations showed that, for AML relapse after BMT, molecular leukaemia eradication could be achieved by DLI so that, in cases where genetic markers are available, molecular monitoring should be performed to assess the efficacy of treatment.     

Myeloperoxidase-deficient polymorphonuclear leucocytes. (V): Relation to FAB-classification and neutrophil alkaline phosphatase activity in primary myelodysplastic syndromes

In 45 cases of primary myelodysplastic syndrome; 16 refractory anaemia (RA), 11 RA with ring sideroblasts (RA+), 13 RA with excess of blasts (RAEB), 5 chronic myelomonocytic leukaemia (CMML), the relations between myeloperoxidase (MPO) activity in polymorphonuclear leucocytes (PMN), neutrophil alkaline phosphatase (NAP) activity, absolute number of PMN and thrombocytopenia were investigated. 11 patients (26%) showed abnormal numbers (greater than 4%) of MPO-deficient PMN and 27 (75%) showed abnormal NAP activity (NAP score; greater than 134.0, less than 15.0), mostly decreased. No significant correlations between MPO activity and NAP activity were demonstrated, nor were any significant correlations found with the other parameters investigated. The FAB-subtypes, RAEB and CMML, showed a significant correlation to thrombocytopenia (p = 0.028) and to pancytopenia (p = 0.024). The findings may support the view that at least some of the myelodysplastic syndromes may be fundamentally the same disease as acute myeloid leukaemia.     

Myeloperoxidase-deficient polymorphonuclear leucocytes (V): Relation to FAB-classification and neutrophil alkaline phosphatase activity in primary myelodysplastic syndromes

In 45 cases of primary myelodysplastic syndrome; 16 refractory anaemia (RA), 11 RA with ring sideroblasts (RA+), 13 RA with excess of blasts (RAEB), 5 chronic my-elomonocytic leukaemia (CMML), the relations between myeloperoxidase (MPO) activity in polymorphonuclear leucocytes (PMN), neutrophil alkaline phosphatase (NAP) activity, absolute number of PMN and thrombocytopenia were investigated. 11 patients (26%) showed abnormal numbers (>4%) of MPO-deficient PMN and 27 (75%) showed abnormal NAP activity (NAP score; >134.0, <15.0), mostly decreased. No significant correlations between MPO activity and NAP activity were demonstrated, nor were any significant correlations found with the other parameters investigated. The FAB-subtypes, RAEB and CMML, showed a significant correlation to thrombocytopenia (p=0.028) and to pancytopenia (p=0.024). The findings may support the view that at least some of the myelodysplastic syndromes may be fundamentally the same disease as acute myeloid leukaemia.     

Surface marker expression in acute myeloid leukaemia at first relapse

Surface markers were studied at first relapse in 66 cases of acute myeloid leukaemia (AML), using a panel of five monoclonal antibodies directed to CD13, CD14, CD15, CD33 and CD34 antigens. At time of relapse, there was increased expression of CD33 (P = 0.002) and CD34 (P = 0.0001), and decreased expression of CD13 (P = 0.004) and CD15 (P = 0.0001) antigens by comparison to initial diagnosis. There was no strict correlation with the FAB classification. However, CD13 and CD33 expression changes preferentially affected granulocytic leukaemias. At relapse, CD14 and CD34 were significantly more expressed in monocytic than in granulocytic AML (P = 0.01 and 0.003 respectively). In a multivariate analysis, CD34 expression was associated with a low CR rate (P = 0.001) and short survival (P = 0.05), whereas CD15 expression was associated with long survival (P = 0.0004). These results suggest that AML tends to relapse with a less differentiated phenotype than observed at diagnosis and that AML with less differentiated phenotype is of poor prognosis after first relapse, as also observed at diagnosis.     

Improved outcome after relapse in children with acute myeloid leukaemia

In the Nordic Society for Paediatric Haematology and Oncology paediatric study acute myeloid leukaemia (AML) 93, event-free survival was 50% and overall survival was 66%, indicating that many patients were cured following relapse. Factors influencing outcome in children with relapsed AML were investigated. The study included all 146 children in the Nordic countries diagnosed with AML between 1988 and 2003, who relapsed. Data on disease characteristics and relapse treatment were related to outcome. Sixty-six percentage achieved remission with survival after relapse (5 years) 34 +/- 4%. Of 122 patients who received re-induction therapy, 77% entered remission with 40 +/- 5% survival. Remission rates were similar for different re-induction regimens but fludarabine, cytarabine, granulocyte colony-stimulating factor-based therapy had low treatment-related mortality. Prognostic factors for survival were duration of first complete remission (CR1) and stem cell transplantation (SCT) in CR1. In early relapse (<1 year in CR1), survival was 21 +/- 5% compared with 48 +/- 6% in late relapse. For children receiving re-induction therapy, survival in early relapse was 29 +/- 6% and 51 +/- 6% in late. Patients treated in CR1 with SCT, autologous SCT or chemotherapy had a survival of 18 +/- 9, 5 +/- 5 and 41 +/- 5%, respectively. Survival was 62 +/- 6% in 64 children given SCT as part of their relapse therapy. A significant proportion of children with relapsed AML can be cured, even those with early relapse. Children who receive re-induction therapy, enter remission and proceed to SCT can achieve a cure rate of 60%.