Prognostic value of colony-stimulating and colony-forming cells in peripheral blood in acute non-lymphoblastic leukemia

Clonal analysis of the response of HL-60 cells to retinoic acid and vitamin D in the presence or absence of leukocyte-conditioned medium

The capacity of retinoic acid (RA) and vitamin D to induce differentiation of HL-60 cells in an agar gel system that permits a high cloning efficiency was studied in the presence or absence of leukocyte-conditioned medium (LCM). Vitamin D was about 10 times more effective in inducing differentiation than RA. LCM significantly increased the differentiation-inductive capacity of both vitamins, although LCM did not have an effect of its own. During the first days of culture, the number of cells per clone increased with either vitamin or LCM alone as compared to control cultures. This suggests that cellular proliferation may be important in the initial phase of the differentiation induction. No synergy in this respect was found between RA and vitamin D in the presence or absence of LCM. Thus it is doubtful whether RA and vitamin D have a true synergistic effect on individual HL-60 cell differentiation as previously described in liquid cultures. Furthermore, the findings suggest that the process of differentiation induction regarding the growing cells in agar gel involves an all-or-none process. The data may also help elucide the observed relationship between the in vitro production of colony stimulating activity and favorable prognosis of AML.

Predictors of response of acute nonlymphocytic leukemia

Given the time and effort expended by investigators and given the large numbers of patients studied, there are disappointingly few "predictors" of response. From the clinical perspective, aside from performance status, age, prior history of toxic exposure, and grossly abnormal organ function, there are essentially no reliable indicators of the likelihood of a patient surviving remission induction therapy. The absence of such indicators might reflect the fact that without grossly abnormal organ function, all patients generally begin with an equal possibility of survival and that events which occur during therapy determine survival. One thing is certain, death directly attributable to leukemic cell overgrowth despite chemotherapy is an extremely rare event. Hence, therapeutic inadequacy in this sense, at the time of initial diagnosis, is not a common cause of treatment failure. Studies aimed at the prediction of leukemic cell responsiveness to therapy have been plagued by two general problems. The first is that the drug sensitivity assays have been quite primitive. For example, the ability of a cell to take up a drug is not synonymous with sensitivity to that drug. Additionally, tests which are dependent upon assays capable of making measurements in only a small subpopulation of cells, such as in vitro clonogenic assays, are likely to have only limited applicability. On the other hand, assays which measure the properties of the leukemic cell population as a whole are incapable of recognizing arabinoside therapy have provided data which suggest that in addition to patient survival three conditions must be satisfied if a complete remission is to occur: the pretherapy leukemic cell mass must be moderate or low, an adequate number of cells must be synthesizing DNA, and cytosine arabinoside must produce significant inhibition of DNA synthesis in vitro. Each factor is consistent with what is known about cytosine arabinoside: it is an S-phase-specific agent which must be incorporated into DNA in order to kill leukemic cells. When the relationship between these same factors and response to combination chemotherapy were studied, not unexpectedly, no relationship was discerned. Finally, in this setting pharmacokinetic studies have demonstrated that the amount of araCTP formed in leukemic cells in vivo when doses of 2 g and 3 g/m2 are administered are indistinguishable, thereby explaining the clinical equivalence of these two dosage levels.(ABSTRACT TRUNCATED AT 400 WORDS)

CFU-gm colony formation of peripheral blood and bone marrow in adult acute leukemia at presentation, during remission, and at relapse

Granulocyte/macrophage colony-forming unit (CFU-gm) formation was studied simultaneously in bone marrow and peripheral blood of 52 previously untreated adult patients with acute non-lymphocytic (ANLL) and 36 with acute lymphoblastic leukemia (ALL). They were followed during induction therapy at monthly intervals while in remission and in 19 ANLL and 22 ALL cases, until relapse. Patients showing a decreased colony number in the marrow but normal or increased colony numbers in the peripheral blood had a high probability of entering remission. Non-responding patients displayed an opposite pattern. The higher the degree of marrow repopulation with granulocytic progenitor cells after induction treatment, the longer remission duration and survival for ANLL patients and the longer survival for ALL patients. CFU-gm formation returned to normal in the early stages of complete remission, but then declined progressively. At ANLL and ALL relapse, colony growth was reduced markedly while cluster formation remained normal. The number of marrow colonies and clusters in ANLL were significantly higher at first and second relapse compared to the growth pattern at first presentation. A similar trend had been observed in ALL, suggesting a selection advantage.

The relationship between growth in agar, karyotype and prognosis in acute leukaemia

The growth pattern in agar culture and the karyotype of bone marrow cells were studied in 79 patients with untreated acute non-lymphocytic leukaemia (ANLL). Results were divided into the following groups: (A) colony and cluster formation; (B) growth of less than 600 small clusters per 10(5) cells; (C) growth of more than 600 small clusters; (D) no growth in agar. Cytogenetically, the patients were divided into 3 categories: NN, normal metaphases only; AN, both abnormal and normal metaphases and AA, abnormal metaphases only. An association was seen between growth pattern and karyotype: the majority of NN patients (33/37) belonged to group (A + B) while in group (C + D) 20/24 patients were AN or AA. 37 patients were prognostically evaluable. The growth pattern in agar but not the cytogenetic pattern had prognostic implications. 25 patients with acute lymphocytic leukaemia (ALL) were also studied at diagnosis. Different growth patterns in agar had no impact on prognosis. No relationship was detected between growth pattern and karyotype in ALL.

Prognostic implications of in vitro colony studies and clonal chromosomal aberrations in adults with acute leukaemia

A comparison was made between in vitro colony culture parameters and chromosomal abnormalities in 44 adult patients with acute leukaemia, with special reference to prognosis. The presence of clonal chromosomal aberrations in some (AN) or all (AA) metaphases of bone marrow cells was a fairly strong indication of poor prognosis, while the absence of abnormal metaphases (NN) was a favourable prognostic sign. 6 of 7 patients in the NN group entered complete remission (CR), as did 8 of 20 in the AN + AA group and 8 of 17 in the group with random loss of chromosomes (NNA). The median survival time for AN + AA patients was 4 months, while for patients without clonal aberrations (NN + NNA) it was 9 months. Of the cultural parameters studied, colony-stimulating activity (CSA) of peripheral leucocytes had the strongest correlation to prognosis. CSA greater than 1 was related to remission (P less than 0.01) and longer survival (P less than 0.05 at 4 months), while 8 patients with CSA less than or equal to 1 were all dead at 8 months. However, very high CSA values (greater than 20) indicate a poor prognosis. Although both chromosome analysis and CSA were of prognostic value, combining the 2 parameters did not improve the prognostic information, mainly because of covariation of NN and CSA greater than 1.

Difference between young and old patients in characteristics of leukemic cells: older patients have cells growing excessively in vitro, with low antigenicity despite high HLA-DR antigens

Fifty-six patients with acute, non-lymphatic leukemia in the initial phase were studied. The poor prognostic signs were excessive in vitro growth, many HLA-DR-positive cells, or a low ratio of leukemic cell antigenicity to HLA-DR positivity and age. The cells from older patients formed more clusters (P less than 0.05), and they had less capacity to stimulate normal allogeneic lymphocytes (P less than 0.05) than those from younger patients. Cells forming many clusters also were more often (P less than 0.01) HLA-DR-positive than those forming few clusters. It is suggested that the prognosis in old patients with acute leukemia is poor in part because their leukemic cells have characteristics different from those of young patients.

Kinetics of colony-forming cells (CFU-c) in adult acute leukemia and their prognostic relevance

The in vitro growth pattern of bone marrow and peripheral blood in soft-agar cultures was studied in 50 previously untreated patients with adult acute leukemia. Patients were followed from time of first diagnosis, during induction treatment, in remission at various time intervals, at relapse and during subsequent re-induction therapy. The distribution of granulopoietic progenitor cells was analysed to determine their prognostic significance for remission incidence, remission duration and survival. All patients revealed an abnormal growth. ANLL patients showing a decreased clone number in the marrow but an increased number of clones in the peripheral blood, had a significant higher probability to enter remission and a significant longer remission than those having clones within normal range at first presentation. On the contrary, ALL patients responding to induction treatment, had a better colony and cluster growth in the bone marrow than those failing to respond. No significant correlation was found between in vitro growth and survival. It is concluded that colony-forming cells of both bone marrow and peripheral blood seems to be of some value in predicting the response rate and length of remission in ANLL and ALL, and in possibly selecting patients with a high chance to respond to current cytostatic regimens.

In vitro colony studies in 87 patients with acute nonlymphoblastic leukemia. Prognostic value of colony-stimulating activity and colony-forming cells

Colony-forming cells (CFU-C) in peripheral blood and bone marrow and colony-stimulating activity (CSA) in mononuclear peripheral white blood cells were studied at diagnosis in 87 patients with acute nonlymphoblastic leukemia (ANLL). Absence of CFU-C in peripheral blood was more frequent in patients who did not enter remission than in those who did, and survival was significantly shorter in CFU-C-negative than in CFU-C-positive patients. No correlation was found between CFU-C in the bone marrow and frequency of remission or survival time. Absence of CSA was significantly more frequent in patients who did not enter remission than in those who did. Only 4 of 28 patients who lacked CSA entered remission. Survival was significantly longer in CSA-positive than in CSA-negative patients. Thus, CSA synthesis in peripheral mononuclear blood cells appears to be a valuable prognostic factor in ANLL.

The prognostic significance of in vitro bone marrow growth pattern in acute non-lymphocytic leukaemia

The growth pattern of bone marrow cells in agar culture was studied in 56 patients with untreated acute non-lymphocytic leukaemia. 4 different growth patterns were recognized: (A) colony and cluster formation, (B) growth of small clusters (3-20 cells) only but less than 600/10(5) cells, (C) growth of small clusters only but more than 600/10(5) cells, and (D) no growth in vitro. Patients in group A and B had a significantly higher remission rate (23/34) than patients in group C and D (3/22). This was true also when only patients below 60 years of age were considered. The median survival time of patients in group A and B was 7.3 months and 9.4 months, and in group C and D 4.0 months and 3.3 months. Identical growth patterns were found for marrow and blood cells in 21 of 27 patients studied and the number of clusters in blood and marrow showed a significant correlation (r = +0.96, P less than 0.001). The mean 3H-labelling index (LI) of myeloblasts determined in 32 patients was 14.8 +/- 7.8% (SD). Patients with LI below 15% tended to have a higher remission rate than patients with LI above 15%. It is concluded that the in vitro growth pattern at diagnosis of bone marrow cells from patients with ANLL is of value in detecting patients with a poor response to current therapeutic protocols. Such information could possibly lead to alternative cytostatic regimes in these patients.