Leukocyte function in patients with leukemia

Evaluation of oral manifestations and head and neck lymphadenopathy in newly diagnosed acute leukemia patients

OBJECTIVES

To determine the frequency of head and neck lymphadenopathy (LAP) and intraoral findings (non-dental/dental) in patients with newly diagnosed acute leukemia (AL).

SUBJECTS AND METHODS

Twenty-eight (52.8%) females and 25 (47.2%) males in a total of 53 patients with newly diagnosed AL with a mean age of 46 years were included in the study. Personal information, the type of AL (AML [acute myelogenous leukemia]/ALL [acute lymphocytic leukemia]), and hematological findings (anemia, neutropenia, and thrombocytopenia) were obtained from medical records. One of two calibrated oral diagnosis and maxillofacial radiology specialists performed extraoral (head and neck LAPs) and intraoral (non-dental and dental) clinical examinations. The Chi-square (χ2) test was used to evaluate categorical variables.

RESULTS

LAP was observed in 22.6% and intraoral findings in 30.2% of the patients. LAP was most commonly observed in the neck and none in the parotid glands. The most intraoral findings were gingival/mucosal bleeding and oral petechiae/ecchymosis. While there was no statistical difference between AML and ALL patients in terms of LAP (p > .05), intraoral findings were observed more in patients with AML (p < .05). Only two (3.8%) patients had dental findings. With a slight difference, intraoral findings were more with thrombocytopenia and LAP with neutropenia.

CONCLUSION

In AL, especially non-dental intraoral findings are common. The fact that dentists working in the oral cavity are often the first specialists to encounter the oral manifestations of AL imposes an important role in early diagnosis and treatment.

Infections in Children With Cancer: The Role of the Presence or Absence of Neutropenia

BACKGROUND

Infections in patients with cancer are a major cause of morbidity and mortality. In most cases, the presence of neutropenia renders them prone to infections to either common or opportunistic pathogens. A wide spectrum of bacterial, viral, or fungal agents is encountered in these patients.

AIM

The aim of this study was to evaluate infection types and pathogens in pediatric patients with cancer with and without neutropenia.

METHODS

A total of 37 pediatric patients with cancer (median age ± 25% quartile, 6.0 ± 2.0% years) with 70 febrile episodes were evaluated at fever's onset and 48 hours later with complete blood count, C-reactive protein, cultures of biological fluids, polymerase chain reaction, and antibody titers.

RESULTS

Of 70 infections, 30 (42.85%) were bacterial, 13 (18.57%) were viral, 3 (4.28%) were fungal, 16 (22.85%) were fever of unknown origin, 18 (25.71%) were opportunistic, and 12 (17.14%) were mixed infections. Neutropenia was detected in 42 (60.0%) of 70 febrile episodes, mainly in patients with hematological malignancies [odds ratio, 2.81 (0.96-8.22); P = 0.059]. Neutropenic patients had higher prevalence of mucocutaneous infections (47.6% vs 7.14%; P = 0.004). Herpes simplex virus 1 infections occurred only in the neutropenic group (14.3%).

CONCLUSIONS

Patients with cancer exhibited a high prevalence of bacterial (42.85%), opportunistic (25.7%), and mixed infections (17.14%). Patients with hematological malignancies and neutropenia presented higher frequency of mucocutaneous and herpes simplex virus 1 infections than the nonneutropenic ones.

Antibiotic Susceptibility of Bloodstream Isolates in a Pediatric Oncology Population: The Case for Ongoing Unit-specific Surveillance

Fever in a neutropenic oncology patient requires rapid initiation of effective empiric antibiotics to prevent mortality. We evaluated the appropriateness of our current empiric antibiotic regimen by assessing local antibiotic-susceptibility patterns in our pediatric oncology patients, and comparing them to the general pediatric patterns in our hospital. All blood culture isolates from pediatric oncology patients were reviewed over a 3-year period. Gram-negative and Gram-positive organisms were reviewed separately, with antibiotic susceptibilities for all unique isolates evaluated, and antibiograms generated and compared with general pediatric patients via the Fisher exact test. A total of 84% of Gram negatives were susceptible to meropenem; all resistant organisms were Pseudomonas aeruginosa, with 50% meropenem susceptibility. A total of 91% of Gram negatives were susceptible to cefepime, including 90% of P. aeruginosa and 80% of Escherichia coli. In total, 96% of Gram positives were vancomycin-susceptible; the only resistant organism was a single enterococcal isolate. In comparison with the general pediatric population, significantly fewer pseudomonal isolates were sensitive to meropenem among the oncology population (50% vs. 89%, P=0.0034). As such, in our population, meropenem does not provide adequate monotherapy against Pseudomonas. Ongoing surveillance of antibiotic resistance in this high-risk population is warranted, to ensure appropriate empiric antibiotic usage.

In Vitro Function of Chronic Myelocytic Leukemia Granulocytes. Effects of Irradiation and Storage

Granulocyte function was studied in 9 patients with untreated, Ph1-positive chronic myelocytic leukemia (CML). The nitroblue tetrazolium reduction by stimulated granulocytes was impaired in all patients; 4 patients also had diminished phagocytosis and 2 others defective Chemotaxis. In spite of this variety of polymorphonuclear (PMN) functional impairments, there is little evidence of increased susceptibility to infections in CML patients. This suggests that CML-PMN leucocytes (PMNs) may be successfully used for transfusion into neutropenic recipients, as previously reported. To evaluate the effects of irradiation and liquid storage on CML-PMNs, 5 of our patients were subjected to leukapheresis by continuous-flow centrifugation in the Aminco Celltrifuge, and granulocyte functional capacities were also evaluated on the cell-rich plasma immediately after collection and after short-term storage at 4°C with or without irradiation (1500 rads). As evaluated by in vitro studies, granulocytes maintained, even after irradiation, functional activities similar to those found immediately after collection up to 24 h of storage at 4°C and presented a moderate loss of function after 48 h. Chemotaxis appeared to be the most sensitive detector for cellular damage of stored leucocytes, irradiated and non-irradiated, so that it might be used for assessment of leucocyte function before transfusion.

Studies on Granulocyte Functions in Patients with Chronic Myeloid Leukemia

Granulcoyte functions, viz. endocytosis, NADPH oxidase activity and iodination by leukocytes, were studied in granulocytes isolated from 17 chronic myeloid leukemia (CIVIL) patients at initial diagnosis (stage I), from 10 patients in relapse (stage II), and 10 patients in acute blastic crisis (stage III). The mean phagocytic index of granulocytes from CML patients was similar to the normal value. NADPH activity decreased as the disease progressed. Thus, the amount of formazan produced was lower in granulocytes from patients in stage II (P < 0.05) and stage III (P < 0.01) than that produced by normal granulocytes. H2O2-Myeloperoxidase-dependent iodination was found to be significantly reduced in granulocytes from all stages of the disease compared to that of normal, stage I (P < 0.01), stage II (P < 0.05) and stage III (P < 0.01). It thus seems that granulocyte function becomes less efficient as the disease progresses towards acute blastic crisis. Immature cells from the same patients carried out these functions at a more reduced level than did their mature counterparts.

Ultrastructural Study of Leukemic Cell Phagocytosis Using the Myeloperoxidase Reaction

The phagocytosis (in the absence of serum factors) of zymosan particles by peripheral leukocytes isolated from ten patients with acute leukemia (AMbL, AMoL, AMML, AUL, ALL and CML-BC) was studied at the electron microscope. An evident phagocytic activity was observed only in the cells in which cytochemical and ultrastructural features suggested that the blast elements belonged to the monocytic series. However, no phagocytosis by unclassifiable leukemic blasts was observed, even though they had some submicroscopic characteristics of the monocytic series. These findings suggest that phagocytic capacity develops during the course of cell differentiation, becoming striking only when the blast cell acquires the ultrastructural features of the pro-monocytic stage. Using the myeloperoxidase reaction, this study also demonstrates a morphological alteration in the degranulation process after the ingestion of zymosan particles in both the blasts and the mature PMN cells of leukemic patients. This defect could be related to the susceptibility to severe infections usually found in subjects with hematological malignancies.

Polymorphonuclear neutrophils and cancer: intense and sustained neutrophilia as a treatment against solid tumors

Polymorphonuclear neutrophils (PMN) are the most abundant circulating immune cells and represent the first line of immune defense against infection. This review of the biomedical literature of the last 40 years shows that they also have a powerful antitumoral effect under certain circumstances. Typically, the microenvironment surrounding a solid tumor possesses many of the characteristics of chronic inflammation, a condition considered very favorable for tumor growth and spread. However, there are many circumstances that shift the chronic inflammatory state toward an acute inflammatory response around a tumor. This shift seems to convert PMN into very efficient anticancer effector cells. Clinical reports of unexpected antitumoral effects linked to the prolonged use of granulocyte colony-stimulating factor, which stimulates an intense and sustained neutrophilia, suggest that an easy way to fight solid tumors would be to encourage the development of intense peritumoral PMN infiltrates. Specifically designed clinical trials are urgently needed to evaluate the safety and efficacy of such drug-induced neutrophilia in patients with solid tumors. This antitumoral role of neutrophils may provide new avenues for the clinical treatment of cancer.

Granulocyte function is stimulated by a novel hexapeptide, WKYMVm, in chemotherapy-treated cancer patients

Bacterial infections are major life-threatening complications in patients receiving cytotoxic drugs. These infections generally occur during periods of neutropenia. It has been suggested that the incidence of neutropenia correlates with the incidence of infections. A synthetic hexapeptide, WKYMVm, which stimulates phosphoinositide hydrolysis in leukocytes, has been shown to activate microbicidal activities of human polymorphonuclear neutrophils. In this study, we evaluate whether WKYMVm stimulates bactericidal activity in neutrophils obtained from patients who received chemotherapy for solid tumors when they were neutropenic. Eight patients and 11 healthy controls were recruited for the study. Patient neutrophils, on day 0 and at 2 weeks after chemotherapy, were collected. Expression of the WKYMVm peptide receptor, on leukocytes, was analyzed by fluorescein-activated cell sorting. Neutrophil bactericidal assays were performed using both reactive oxygen species generation and intracellular killing. Expression of the WKYMVm peptide receptor on leukocytes showed no difference in the treated patients compared to healthy controls. WKYMVm increased bactericidal activities, in a dose-dependent fashion, of control neutrophils compared to treated patient neutrophils obtained on day 0. WKYMVm markedly stimulated bactericidal activity of treated patient neutrophils obtained at 2 weeks after chemotherapy compared to treated patient neutrophils obtained on day 0. WKYMVm augmented neutrophil bactericidal activity was noted at low concentration but was suppressed at higher concentrations of 5-fluorouracil. WKYMVm augmented neutrophil bactericidal activity was not suppressed by cisplatin. WKYMVm has the potential for increasing neutrophil bactericidal activity in chemotherapy-treated cancer patients.

Chronic myelogenous leukemia as a paradigm of early cancer and possible curative strategies

The chronological history of the important discoveries leading to our present understanding of the essential clinical, biological, biochemical, and molecular features of chronic myelogenous leukemia (CML) are first reviewed, focusing in particular on abnormalities that are responsible for the massive myeloid expansion. CML is an excellent target for the development of selective treatment because of its highly consistent genetic abnormality and qualitatively different fusion gene product, p210(bcr-abl). It is likely that the multiple signaling pathways dysregulated by p210(bcr-abl) are sufficient to explain all the initial manifestations of the chronic phase of the disease, although understanding of the circuitry is still very incomplete. Evidence is presented that the signaling pathways that are constitutively activated in CML stem cells and primitive progenitors cooperate with cytokines to increase the proportion of stem cells that are activated and thereby increase recruitment into the committed progenitor cell pool, and that this increased activation is probably the primary cause of the massive myeloid expansion in CML. The cooperative interactions between Bcr-Abl and cytokine-activated pathways interfere with the synergistic interactions between multiple cytokines that are normally required for the activation of stem cells, while at the same time causing numerous subtle biochemical and functional abnormalities in the later progenitors and precursor cells. The committed CML progenitors have discordant maturation and reduced proliferative capacity compared to normal committed progenitors, and like them, are destined to die after a limited number of divisions. Thus, the primary goal of any curative strategy must be to eliminate all Philadelphia positive (Ph+) primitive cells that are capable of symmetric division and thereby able to expand the Ph+ stem cell pool and recreate the disease. Several highly potent and moderately selective inhibitors of Bcr-Abl kinase have recently been discovered that are capable of killing the majority of actively proliferating early CML progenitors with minimal effects on normal progenitors. However, like their normal counterparts, most of the CML primitive stem cells are quiescent at any given time and are relatively invulnerable to the Bcr-Abl kinase inhibitors as well as other drugs. We propose that survival of dormant Ph+ stem cells may be the most important reason for the inability to cure the disease during initial treatment, while resistance to the inhibitors and other drugs becomes increasingly important later. An outline of a possible curative strategy is presented that attempts to take advantage of the subtle differences in the proliferative behavior of normal and Ph+ stem cells and the newly discovered selective inhibitors of Bcr-Abl. Leukemia (2003) 17, 1211-1262. doi:10.1038/sj.leu.2402912

Granulocyte functions in children with cancer are differentially sensitive to the toxic effect of chemotherapy

To analyze the toxicity associated to chemotherapy upon granulocytes, different functional assays were performed, within days of drug exposure and at time of bone marrow recovery, on polymorphonuclear neutrophils (PMN) from children with cancer. There were no significant postchemotherapy changes in the expression of the different receptors studied nor in the phagocytosis of Staphylococcus aureus 42D. By contrast, a significant decrease was observed in H2O2 production in PMN recently exposed to chemotherapy with both cytofluorometric and chemiluminescence assays. There was also a decrease in the production of O2- and in chemotaxis; finally, the intracellular killing of S. aureus 42D and Escherichia coli was reduced. In patients having recovered from drug-induced bone marrow aplasia, PMN functions were found to be normal except for bactericidal activity which was still defective. The observations indicate that, in patients exposed to chemotherapy, some PMN functions are transiently altered, whereas microorganism cell killing is continuously impaired.

The role of integrins in granulocyte dysfunction in myelodysplastic syndrome

The aim of the present study was to evaluate the function of granulocytes in 20 patients affected by myelodysplastic syndrome (MDS) and correlate this with the expression of surface membrane integrins. The granulocytes showed a deficit in chemotaxis (34 +/- 12 vs 84 +/- 10, p < 0.01) in superoxide release (12 +/- 7 vs 30 +/- 10, p < 0.01) and in aggregation 12 +/- 6 vs 36 +/- 9, p < 0.01 using fMLP as stimulus. We also demonstrated with cytofluorimetric and alkaline phosphatase immunoenzymatic analysis (APAAP), decreased expression of CD11b/CD18 receptor detected by OKM1 (p < 0.001) and CD18 detected by MoAb IOT-18 (p < 0.001). PMNs CD11b/CD18 up-regulation and APAAP image analysis studies showed a lower level of expression of CD11b/CD18 in granulocytes from MDS patients compared to controls (p < 0.001). We concluded that granulocyte dysfunction in MDS may be correlated with modification of leukocyte integrins.

The CD11/CD18 granulocyte adhesion molecules in myelodysplastic syndromes

We have evaluated the function of granulocytes in 14 patients suffering from myelodysplastic syndrome (MDS). We also evaluated the functional and immunochemical activities of five monoclonal antibodies (MoAbs) reactive with the CD11/CD18 leucocyte adhesion molecules of granulocytes. Granulocytes showed a decrease in chemotaxis (P < 0.001) and in aggregation (P < 0.01) using various agents as a stimulus. Cytofluorimetric and immunoenzymatic assays with alkaline phosphatase (APAAP) analysis showed decreased expression of the CD11b/CD18 receptor detected by OKM1 (P < 0.001). Despite LFA-1 and-CD11a/CD18 was expressed in normal amounts. The studies of upregulation of granulocytes CD11b/CD18 and image analysis of immunochemical preparation (APAAP) demonstrated decreased expression of CD11b/CD18 in granulocytes from MDS compared to controls (P < 0.001). We conclude that granulocyte dysfunction in MDS may be correlated with decreased expression of surface CD11b/CD18 leucocyte adhesion molecules or their structural modification.

Superoxide anion-generating activity of polymorphonuclear leukocytes and monocytes in patients with lung cancer

Superoxide anion (O2-) production by polymorphonuclear leukocytes (PMN) and monocytes (MN) was measured in the peripheral blood of 70 patients with lung cancer. The O2- production by these cells was decreased in many, but not all, patients. The incidence of patients with lower O2- production increased as the stage advanced. The correlation between O2- production by these cells and peripheral blood smears was evaluated in patients with cancer. Patients with 80% granulocytes and 40% monocytes or more in their peripheral blood had a significantly lower O2- production by PMN and MN compared with those with less than 80% granulocytes and 40% monocytes, respectively. These results indicate that an abnormally increased number of granulocytes and monocytes in the peripheral blood of patients with cancer may depress immunoregulatory function. In addition, decreased O2- production by these cells should be considered when assessing the defense mechanisms and susceptibility to infection of these patients.

Differential endocytosis of fluorescein iso-thiocyanate-concanavalin A by normal and chronic myeloid leukemic granulocytes

Isolated granulocytes from normal individuals and patients suffering from chronic myeloid leukemia (CML) displayed different fluorescent patterns on treatment with fluorescein isothiocyanate concanavalin A (Fl-Con A). The ligand was internalized by 86% of the normal granulocytes, while 80% of the leukemic granulocytes exhibited Fl-Con A localized on the cell periphery. In further experiments, pretreatment of the normal granulocytes with cytochalasin B, iodoacetamide, 2-deoxyglucose and sodium fluoride (but not with sodium azide or dinitrophenol) was found to drastically inhibit internalization of the ligand. However, pretreatment of granulocytes from CML patients with cytochalasin B and 2-deoxyglucose, caused only a little alteration in the pattern of Fl-Con A labelling relative to untreated cells. These results indicate that CML granulocytes are defective in their ability to endocytose Fl-Con A. We suggest that this differential interaction between Fl-Con A and normal and leukemic granulocytes is a convenient system to study the initial steps in receptor mediated endocytosis of Concanavalin A.

Superoxide production of polymorphonuclear leukocytes in surgical patients with gastric cancer

Superoxide production (SOP) by polymorphonuclear leukocytes (PMNs) in 65 gastric cancer patients, who were in preoperative state and had received no medical therapy, was assayed in order to evaluate the bactericidal activity of PMNs in cancer patients, as well as to determine the correlation of SOP by PMNs with postoperative prognoses and several factors by which extent of disease and the clinical or histological character of gastric carcinoma were defined. Patients with stage II disease had a tendency to have an increased SOP by PMNs, and furthermore, as the disease progressed, the SOP by PMNs decreased with significant depression being noted in stage III and IV cases compared to healthy controls. Significantly reduced SOP by PMNs was observed in n2 and n3 cases and with se, si, sei and/or ps(+) pathological invasion. SOP by PMNs in patients with Borrmann II type and/or poorly differentiated adenocarcinoma was significantly depressed. Patients who suffered from septic complications showed a significant depression in SOP by PMNs compared with the controls and no complication group. These results suggest that advanced gastric cancer patients may have defective oxidative PMN metabolism, and that a decrease of SOP is a contributory cause of high susceptibility to postoperative infection in cancer patients.

Functional characterization of the cells in chronic neutrophilic leukemia

Light and electron microscopy of neutrophils from chronic neutrophilic leukemia (CNL) did not reveal differences from normal mature neutrophils. However, functional characterization of CNL cells showed marked differences when compared to normal cells. CNL neutrophils were much less viable in suboptimal conditions. Their survival was further reduced by autologous serum and was corrected by normal human serm. CNL cells showed very active phagocytosis, but their bactericidal activity was reduced in suboptimal conditions. The total content of lysozyme and beta-glucuronidase was lower in CNL cells compared to normal neutrophils, but the release of these enzymes from stimulated cells was much higher than normal. This observation is compatible with a marked lysosomal lability. Cells from the patients' peripheral blood and bone marrow showed excessive growth in CFU-C assays. Marked susceptibility of CNL cells to cytotoxic activity of cold agglutinins, SLE sera, and CSFs was observed and may signify qualitative and/or quantitative differences in the membrane structure of CNL neutrophils, as compared to normal cells.

A new neutrophil candida killing test: chromium-51 release from Candida guilliermondii

Neutrophil candidacidal function was measured by a chromium-51 (51Cr) release technique, using Candida guilliermondii as the test organism. The effect of varying the neutrophil:candida ratio, the time course of 51Cr release, the effect of different serum concentrations, and the reproducibility of the technique were investigated. Results from 33 experiments, using neutrophils from 35 normal donors and six patients with known neutrophil defects, show the technique to be a reliable and reproducible assay of candida killing. The chromium release assay has the advantage of being easy to perform and not liable to subjective errors.

Gram-negative bacteremia. IV. Re-evaluation of clinical features and treatment in 612 patients

Clinical features and specific aspects of treatment were evaluated in 612 patients with gram-negative bacteremia observed over a 10 year period. Coagulation abnormalities or thrombocytopenia were observed in 64 per cent of the patients. Evidence of disseminated intravascular coagulation (DIC) was found in approximately 10 per cent of them but was of sufficient severity to be associated with subcutaneous or visceral bleeding in 3 per cent of them. The frequency of coagulation abnormalities, other than DIC, was greater in patients with more severe underlying disease but DIC occurred with similar frequency irrespective of the severity of underyling host disease. Coagulation abnormalities of all types were associated with increased fatality rates. Hypothermia was noted in 13 per cent of the patients at the onset of bacteremia but was transient and was not associated with increased fatality. Failure to mount a febrile response greater than 99.6 degrees F within the first 24 hours of bacteremia was associated with a significant increase in fatality rates. Prior corticosteroid therapy diminished the febrile response to bacteremia. Age, underlying host disease, granulocytopenia, congestive heart failure, diabetes mellitus, renal insufficiency, nosocomial infections, and antecedent treatment with antibiotics, corticosteroids, and antimetabolites significantly increased fatality rates. Appropriate antibiotic treatment reduced the fatality rate of those with bacteremia by approximately one-half among patients in each category of severity of underlying host disease. In addition, it was shown that early appropriate antibiotic therapy also reduced the frequency with which shock developed by one half. Even after development of shock, appropriate antibiotic therapy significantly reduced fatality rates. The use of combinations of antibiotics could not be demonstrated to significantly improve survival rates. Minimal differences in therapeutic efficacy could be demonstrated between individual antibiotics and various combinations of antimicrobials. Shock occurred in approximately 40 per cent of the patients and its frequency was not influenced by the species of etiologic agent. Contrary to previous reports, corticosteroid therapy in patients with shock did not enhance survival and treatment with an average of 4.0 g/day of hydrocortisone or its equivalents was associated with a significant increase in fatality rates.

Effect of chemotherapeutic agents on metabolic and bactericidal activity of polymorphonuclear leukocytes

Blood was obtained on 36 occasions from 12 healthy adult volunteers and the polymorphonuclear leukocytes (PMNL) were separated. PMNL hexose monophosphate shunt activity of whole blood and ability of separated cells to phagocytize and kill E. coli were evaluated when the PMNL were incubated with normal pooled sera and sera containing therapeutic concentrations of either 15 cancer chemotherapeutic drugs singly and in combination or 9 antibiotics. Resting and stimulated HMPS activity was significantly (p less than 0.025 to p less than 0.001) decreased by cyclophosphamide, carmustine (BCNU), high dose prednisone (pred), vinblastine (vinbl) and vincristine (vinc) and significantly (p less than 0.025 to p less than 0.01) increased by combinations of vinc-pred, vinc-predasparaginase, 6-mercaptopurine (6MP)-methotrexate (Mtx) and 6MP-Mtx-pred when compared to controls. No significant differences in HMPS activity of PMNL were found when exposed to various antimicrobial agents singly or in combination. The killing of E. coli by PMNL was significantly (p less than 0.001) decreased when exposed to BCNU, high concentration pred or combinations of 6MP-Mtx-pred, 6MP-Mtx and vinc-vinbl-pred but not when exposed to other chemotherapeutic agents. This study shows a disparity in results obtained when evaluating PMNL function by HMPS activity and bactericidal assay. In addition, a functional impairment in PMNL exposed to various antimetabolites occurred at a time when they exhibited normal morphology.

Oral anticandidal prophylaxis in patients undergoing chemotherapy for acut- leukemia

Fifty-six untreated patients with acute leukemia (38 acute myelogenous leukemia, 16 acute lymphoblastic leukemia, and 2 blast crisis of chronic granulocytic leukemia) were randomized on admission to one of three groups--one to receive oral anticandidal prophylaxis through the period of remission induction chemotherapy with nystatin, another to receive natamycin, and the third to receive no anticandidal prophylaxis. Neither of the first two groups show any advantage over the last and it is concluded that provided gut sterilization regimes are not employed, prophylactic oral anticandidal treatment is of no value in these patients and should be reserved until there is clinical evidence of infection.

Preleukemia: does it exist?

In acute myeloid leukemia (AML), many of the remaining normal-appearing cells exhibit various abnormalities. An interpretation is that these cells are descendants of leukemic cells which have succeeded in overcoming the major final differentiation block that exists in AML. Direct evidence is quoted that red cell precursors in AML are of leukemic descent and it is claimed that the target cell of AML is the pluripotent stem cell. Next, evidence has been compiled that all three cell lines (red cell, n. granulocytes, platelets) exhibit qualitative defects in "prelukemia." Hence it is postulated that preleukemia per se doses not exist but that preleukemic states which with a rather high frequency sooner or later end in overt AML are actually true leukemias that, however, differentiate reasonably well. Another way of phrasing it is that preleukemic states are AMLs that present in partial and sometimes long-lasting remission, which only after months to years lose their differentiation ability and then are classified as AML.

Defective neutrophil function in chronic granulocytic leukaemia

The ability of neutrophils to phagocytose, kill and digest Candida guilliermondii was investigated in twelve patients with chronic granulocytic leukaemia (CGL). Following ingestion of organisms there was considerable reduction in the ability of CGL cells to kill Candida and this was not explained by a mild impairment of phagocytosis. Histochemical staining showed that granules containing lysosomal enzymes disappear form the cytoplasm of normal neutrophils during killing and digestion of the fungus, while in CGL cells the granules remain. Quantitative measurement confirmed loss of peroxidase from normal neutrophils during Candida killing but no loss from CGL neutrophils. The primary granules of CGL neutrophils do not fuse with and discharge their contents into the phagocytic vacuole and this explains their impaired ability to kill and digest Candida.

Neutrophil function in gram-negative rod bacteremia. The interaction between phagocytic cells, infecting organisms, and humoral factors

To assess the phagocytic and bactericidal function of neutrophils in the acute stages of gram-negative rod bacteremia, cells from 30 nonleukopenic patients were studied in a test system utilizing plasma obtained simultaneously with culture-positive blood, the autologous infecting strain, and two laboratory test strains of Staphylococcus aureus and Pseudomonas aeruginosa. Results were compared to those obtained with normal neutrophils and plasma. Patient and control plasma were simultaneously tested with each source of phagocytic cells to localize any abnormalities. Four patients had a defect against their infecting strain, 33% of the inoculum phagocytized and killed versus 80% by controls. In these cases differences were localized to the patients' plasma, as normal plasma tested with patients' cells reversed the defect. Thus, four patients had impaired opsonization when compared to normal controls, but we also observed that 11 of 30 bacteremic isolates, all Escherichia coli, showed absolute or relative resistance to phagocytosis in the patient and control assay system. No intrinsic granulocyte killing abnormalities were noted. There was poor correlation between results obtained with infecting strains compared to laboratory test organisms. We conclude that in patients without evidence of an inherited neutrophil bactericidal disorder, recurrent infection, or treatment with cytotoxic drugs, intrinsic bactericidal defects are uncommon at the onset of gram-negative bacteremia, and impaired opsonization is the most commonly encountered cause of neutrophil dysfunction.

[Granulocyte dysfunction. Part II. Secondary defects. (authors transl)]

In the first part we reviewed both the molecular basis of granulocyte function and the inborn defects. The present chapter summarizes our knowledge of the secondary defects of chemotaxis, opsonisation, phagocytosis and intracellular microbicidal activity.

Ascorbate and phagocyte function

Scorbutic guinea pig neutrophils (PMN) were found to produce H2O2 and kill Staphylococcus aureus as well as control PMN, suggesting that ascorbate does not contribute significantly to phagocyte H2O2 production or bacterial killing. Total and reduced ascorbate contents of human PMN was observed to fall upon phagocytosis, whereas dehydroascorbate increased to a lesser extent. These observations are consistent with the view that ascorbate constitutes a functional part of the PMN's redox-active components and may thus function to protect cell constituents from denaturation by the oxidants produced during phagocytosis.

Anesthesia and the immune system

Anesthesia and operation may impair the immune system so that bacterial growth and tumor spread may occur more readily, and host response to transplanted tissue and allergenic substances may be altered. Suggestions are presented regarding the anesthetic management of patients at risk from infection or tumor spread.

Leukocyte function in children with malignancies

Blood was obtained on 414 occasions from 106 children with acute lymphocytic leukemia (ALL) or solid tumors. Resting and stimulated hexose monophosphate shunt (HMPS) activity and unstimulated and stimulated nitroblue tetrazolium (NBT) dye reduction were assessed on each sample. The values obtained were compared to similar determinations made on blood obtained from 178 healthy children. Resting HMPS activity of all patients with malignant diseases was significantly (p smaller than 0.01) greater, and ability to stimulate HMPSP activity significantly (p smaller than 0.01) less than that noted in healthy control patients. Unstimulated NBT dye reduction of leukocytes obtained from patients with malignant disorders was significantly (p smaller than 0.01) less than that observed in healthy control children. No significant differences were noted in HMPS activity or NBT dye reduction in patients with ALL, rhabdomyosarcoma, or other solid tumors who had bacterial infection when compared to uninfected patients, or when patients were categorized according to the type of chemotherapy provided. HMPS activity and NBT dye reduction of patients with ALL prior to treatment, in remission, and during episodes of relapse did not differ from each other. Thus, a functional impairment in leukocyte function was noted in patients with ALL even when their peripheral blood and bone marrow cells exhibited normal morphology.

Complications and total care of a child with acute leukemia

The complications which occur in a child with acute leukemia depend on the stage of the disease and the therapeutic regiman. Most children will present with some manifestation of marrow failure. An occasional child will have marked leukocytosis and disturbance of organ function due to massive leukemic infiltrates. Metabolic disturbances such as hyperuricemia and hyperphosphatemia-hypocalcemia may develop, expecially after therapy is initiated. The myelosuppression and immunosuppression due to drug toxicity may result in opportunistic infections. Other toxicities which can occur with a chemotherapeutic regimen are numerois and varied, and the physician must be cognizant of them in order to minimize damage. Therapy to the central nervous system, either for subclinical or clinical disease, has been associated with a variety of symptoms ranging from meningismus to paraplegia and death. To prevent the development of these complications, and to manage them effectively if they occur, the physician must be knowlegeable about their etiology, clinical and laboratory manifestations, and treatment.

Granulocyte function in chronic granulocytic leukaemia. I. Bactericidal and metabolic capabilities during phagocytosis in isolated granulocytes

The ingestion, bactericidal activity and metabolism of isolated mature neutrophil leucocytes during phagocytosis was studied in 17 patients with chronic granulocytic leukaemia (CGL) with the simultaneous use of normal controls. Seven patients had received no treatment and the others had been treated previously with Busulphan. The phagocytic indices for killed yeast cells did not differ from those of the controls. A diminished bactericidal activity against E. coli was found in nine CGL cases. The bactericidal capacity closely correlated with the degree of leucocytosis since patients with a WBC count of 90 000/mul or higher with one exception showed decreased bactericidal activities while patients with WBC counts below 90 000/mul with two exceptions showed normal bactericidal activities. The [I-14C]-glucose oxidation during phagocytosis was increased in four patients and decreased in three patients. Some correlation was found between abnormally high or low [I-14C]glucose oxidation and diminished bactericidal activity. The intracellular iodination reaction during phagocytosis was decreased in 10 cases while the extracellular iodination was increased in six cases and decreased in one case. The data for granulocyte iodination did not correlate with WBC count, bactericidal capacity or [I-14C]glucose oxidation. The time course for the bactericidal activity and granulocyte iodination seemed to deviate from the controls indicating a slow initial ingestion and/or degranulation phase. The CGL granulocyte content of myeloperoxidase was normal or increased, the lysozyme content was decreased in half of the cases while the amount of antibacterial cationic proteins was increased, normal or low. The present findings indicate a variety of abnormalities in the mature CGL granulocyte, which are not closely interrelated.