Routine immunophenotyping in acute leukemia: Role in lineage assignment and reassignment.

Diagnostic evaluation of acute leukemia at Roswell Park Cancer Institute has routinely included immunophenotyping by multiparameter flow cytometry. In a retrospective analysis of 646 cases, morphology and cytochemistry established lineage in 612, but not in 34 (5%), of which 26, 5, and 3 were myeloid, undifferentiated, and lymphoid, respectively, based on immunophenotyping. In addition, immunophenotyping changed the lineage assigned based on morphology and cytochemistry in 11 cases (2%); 8 changed from lymphoid to myeloid, and 3 from myeloid to lymphoid. The data support routine inclusion of at least limited immunophenotyping in the diagnostic evaluation of acute leukemia.

Impaired alveolar macrophage response to Haemophilus antigens in chronic obstructive lung disease.

RATIONALE: Interactions of nontypeable Haemophilus influenzae (NTHI) with macrophages are implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, the immunologic mechanisms that mediate NTHI-macrophage inflammation are poorly understood. Outer membrane protein (OMP) P6 and lipooligosaccharide (LOS) of NTHI are potent immunomodulators. We theorized that alveolar macrophages in COPD possess fundamental immune defects that permit NTHI to evade host responses. OBJECTIVE: To test this hypothesis, we obtained human alveolar and blood macrophages from exsmokers with COPD, exsmokers without COPD, and nonsmokers. METHODS: Alveolar and blood macrophages from each donor were incubated with purified LOS and OMP P6 and with OMP P2 and the total outer membrane preparation (0.1-1 microg/ml). MEASUREMENTS: Supernatants (24 h) were assayed for IL-1beta, TNF-alpha, IL-10, IL-12, and IL-8 by multianalyte multiplexed flow cytometry. RESULTS: Comparative induction of COPD and non-COPD alveolar macrophages by LOS and OMP P6 revealed diminished IL-8, TNF-alpha, and IL-1beta responses of COPD alveolar macrophages (p < or = 0.03 for each). COPD alveolar macrophages also had diminished responses to total outer membrane (p < or = 0.03 for each). In contrast, COPD blood macrophages had no significant differences among donor groups in IL-8, TNF-alpha, or IL-1beta responsiveness to NTHI antigens. Diminished IL-12 responses of COPD blood macrophages to NTHI antigens, compared with nonsmokers, could not be independently dissociated from group differences in age and pack-years. CONCLUSIONS: These findings support a paradigm of defective immune responsiveness of alveolar macrophages, but not blood macrophages, in COPD.

A quantitative exploration of surface antigen expression in common B-cell malignancies using flow cytometry.

The use of flow cytometry to diagnose hematological malignancies has become routine due to its ability to often differentiate between morphologically similar diseases based on antigens expressed on the surface of malignant cells. In an attempt to expand on the utility of flow cytometry in the study of B-cell malignancies we have used the most reliable quantitative methodology, QIFI (quantitative indirect immunofluorescence assay), to study the expression of CD5, CD10, CD11c, CD19, CD20, CD22, CD23, and CD79b in 384 cases of several common B-lineage malignancies, including: B-ALL, CLL, SLL, hairy cell leukemia, diffuse large B-cell lymphoma, and follicular lymphoma. The impetus behind this extensive, single institution study of surface antigens was two-fold: evaluating similarities and differences of antigen expression between B-cell neoplasms and finding additional clinical utility for the quantitative flow cytometric data generated. Our results show that each distinct malignant histology has its own quantitative pattern of surface antigen expression. In most cases, these quantitative patterns do not increase the ability of flow cytometry to distinguish between them. However, a high expression of specific antigens on a given B-cell malignancy may potentially identify optimal therapeutic targets for current and/or future monoclonal antibody-based therapies.

Flow cytometer in the infrared: inexpensive modifications to a commercial instrument.

BACKGROUND: The application of molecules that fluoresce in the infrared (IR) region to measure cell products would be enhanced by a flow cytometer capable of measuring them. To our knowledge, none exist at this time. Accordingly, we have developed such an instrument. METHODS: A Becton Dickinson LSR flow cytometer was modified to include a small 785-nm IR diode laser the size of a C cell battery with 44-mW output power. The instrument was modified further to accommodate this laser in addition to a 405-nm solid-state laser, a 488-nm air-cooled argon laser, and a 658-nm solid-state laser. Because the IR laser is dangerous to the eye, the laser beams were viewed for optical alignment using a CCD camera and video monitor. An avalanche photodiode was used in place of a photomultiplier tube because its detection sensitivity in the IR region is superior. RESULTS: To assess performance, scatter and fluorescence measurements were made using microspheres that fluoresce in the IR region, and human leukocytes were stained with CD45 biotin followed by a streptavidin conjugated with an IR dye. An avalanche photodiode was 2.3 to 2.8 times more sensitive than a photomultiplier tube for detecting IR fluorescence. Cells stained with CD45 biotin and avidin conjugated with an IR dye could easily be resolved and their fluorescence quantified; there was virtually no autofluorescence. In addition, a lipophilic membrane dye that emits in the IR region was studied. HL60 cells were stained with this dye and they exhibited bright fluorescence intensity. CONCLUSION: A commercial instrument could be modified to accommodate an IR laser for exciting dyes that fluoresce in the IR region. This new capability will extend the range of fluorescence that can be measured by flow cytometry.

Discrimination of resident and infiltrated alveolar macrophages by flow cytometry in influenza A virus-infected mice.

Laser flow cytometric analysis was used in conjunction with in vivo labeling with the lipophilic fluorescent dye DiIC18(5)-DS to discriminate resident alveolar macrophages from newly infiltrating monocytes/macrophages in mice with and without pulmonary influenza A virus infection. Leukocytes in bronchoalveolar lavage (BAL) and peripheral blood were analyzed by 2-color flow cytometry as a function of time following intravenous injection of DiIC18(5)-DS. At 4 hours, dye-positive leukocytes were present in both BAL and blood of normal mice, indicating that DiIC18(5)-DS rapidly crossed the pulmonary endothelial-epithelial barrier. At 4 days after dye injection, 98% of BAL cells were DiIC18(5)-DS positive, and almost all of these were monocytes/macrophages based on labeling with fluorescein isothiocyanate (FITC)-conjugated antibody to the Mac-3 marker. Only 3.2% +/- 0.3% of peripheral blood monocytes (approximately 0.16% of total peripheral blood leukocytes) were DiIC18(5)-DS positive at 6 days after injection, whereas > 95% of BAL leukocytes were strongly dye-positive on days 6 to 28. When DiIC18(5)-DS was injected in mice 6 days prior to intranasal challenge with influenza A, flow cytometry indicated that 57.8% 5.6% and 60.7% +/- 8.5% of macrophages/monocytes in BAL were newly infiltrated (i.e., DiIC18(5)-DS negative, Mac-3 positive) at 4 and 7 days, respectively, post viral infection. The discrimination of subpopulations of resident and newly recruited macrophages in BAL should facilitate future mechanistic studies on pulmonary infection and inflammatory lung injury.

Human CD4+ effector memory T cells persisting in the microenvironment of lung cancer xenografts are activated by local delivery of IL-12 to proliferate, produce IFN-gamma, and eradicate tumor cells.

The implantation of small pieces of human primary lung tumor biopsy tissue into SCID mice results in a viable s.c. xenograft in which the tissue architecture, including tumor-associated leukocytes, tumor cells, and stromal cells, is preserved in a functional state. By monitoring changes in tumor volume, gene expression patterns, cell depletion analysis, and the use of function-blocking Abs, we previously established in this xenograft model that exogenous IL-12 mobilizes human tumor-associated leukocytes to kill tumor cells in situ by indirect mechanisms that are dependent upon IFN-gamma. In this study immunohistochemistry and FACS characterize the early cellular events in the tumor microenvironment induced by IL-12. By 5 days post-IL-12 treatment, the constitutively present human CD45(+) leukocytes have expanded and infiltrated into tumor-rich areas of the xenograft. Two weeks post-treatment, there is expansion of the human leukocytes and complete effacement of the tumor compared with tumor progression and gradual loss of most human leukocytes in control-treated xenografts. Immunohistochemical analyses reveal that the responding human leukocytes are primarily activated or memory T cells, with smaller populations of B cells, macrophages, plasma cells, and plasmacytoid dendritic cells capable of producing IFN-alpha. The predominant cell population was also characterized by FACS and was shown to have a phenotype consistent with a CD4(+) effector memory T cell. We conclude that quiescent CD4(+) effector memory T cells are present within the tumor microenvironment of human lung tumors and can be reactivated by the local and sustained release of IL-12 to proliferate and secrete IFN-gamma, leading to tumor cell eradication.

Precursor B lymphoblastic leukemia with surface light chain immunoglobulin restriction: a report of 15 patients.

We describe 15 patients (9 children) with precursor B-cell (pB) acute lymphoblastic leukemia (ALL) with surface immunoglobulin (sIg) light chain restriction revealed by flow cytometric immunophenotyping (FCI). The same sIg+ immunophenotype was present at diagnosis and in 3 relapses in 1 patient. In 15 patients, blasts were CD19+ CD10+ (bright coexpression) in 14, CD34+ in 12, surface kappa+ in 12, surface lambda+ in 3; in 8 of 8, terminal deoxyribonucleotidyl transferase (TdT)+; and in 4, surface IgD+ in 2 and surface IgM+ in 1. The 3 CD34- cases included 1 TdT+ case, 1 with t(1;19)(q23;p13), and 1 infant with 70% marrow blasts. One adult had CD10- CD19+ CD20- CD22+ CD34+ TdT+ sIg+ blasts with t(2;11)(p21;q23). Blasts were L1 or L2 in all cases (French-American-British classification). Karyotypic analysis in 12 of 12 analyzable cases was negative for 8q24 (myc) translocation. Karyotypic abnormalities, confirmed by fluorescence in situ hybridization in 6 cases, included hyperdiploidy, t(1;19)(q23;p13), t(12;21)(p13;q22), t(9;22)(q34;q11), t(2;11)(p21;q23), and trisomy 12. The sIg light chain restriction in pB ALL might be present in neoplasms arising from the early, intermediate, and late stages of precursor B-cell maturation; sIg light chain restriction revealed by FCI does not necessarily indicate a mature B-cell phenotype, further emphasizing the importance of a multidisciplinary approach to diagnosing B-lymphoid neoplasms.

Expression of the neural cell adhesion molecule CD56 is not associated with P-glycoprotein overexpression in core-binding factor acute myeloid leukemia.

Acute myeloid leukemia (AML) with rearrangement of the core-binding factor (CBF) alpha or beta subunit gene has a favorable prognosis, but CD56 expression in CBFalpha-AML is associated with short disease-free survival. A proposed mechanism is overexpression of the multidrug resistance (MDR) protein P-glycoprotein (Pgp). CD56 expression, Pgp expression and function, and expression of the additional MDR proteins multidrug resistance protein-1 (MRP-1), lung resistance protein (LRP) and breast cancer resistance protein (BCRP) were studied in pretreatment blasts from 25 CBF-AML patients. CD56 expression was frequent in CBFalpha but rare in CBFbeta, and Pgp expression and function were frequent in both subtypes. CD56 expression did not correlate with Pgp expression or function, nor with expression of the other MDR proteins. Treatment failure associated with CD56 expression in CBFalpha-AML is not likely attributable to Pgp.

Multiparameter data acquisition and analysis of leukocytes.

For data acquisition, each supplier provides the software necessary and unique to its instrument. For data analysis, the same software may be used. In addition, several second party vendors provide software often with more capabilities than that provided by the instrument companies. Because of the increase in multiparameter data acquisition, we describe one method for validating instrument performance prior to data acquisition. The fundamentals of data analysis leading to a generic strategy for analysis of any number of parameters are described. This generic approach is designed to simplify the increasing complexity of multiparameter data analysis.

Analysis of fluorescent protein expressing cells by flow cytometry.

The process for transfection of cells with expression and gene-trap vectors expressing fluorescent reporter proteins is described. The measurement and sorting of discrete populations of transfected cells is also described and illustrated. Of particular importance, the maintenance of stability may be important and a simple strategy to monitor this has been developed. Finally, an effective method for improving the ability to measure low-level fluorescence from autofluorescence is described.

Additional cytogenetic abnormalities in adults with Philadelphia chromosome-positive acute lymphoblastic leukaemia: a study of the Cancer and Leukaemia Group B.

We analysed the nature and prognostic significance of secondary cytogenetic changes in 111 newly diagnosed adults with acute lymphoblastic leukaemia (ALL) and t(9;22)(q34;q11.2) or its variants. Secondary aberrations were seen in 75 (68%) patients. They included, in order of descending frequency: +der(22)t(9;22), +21, abnormalities of 9p, high hyperdiploidy (>50 chromosomes), +8, -7, +X and abnormalities resulting in loss of material from 8p, gain of 8q, gain of 1q and loss of 7p. Eighty patients (72%) had > or =1 normal metaphase in their karyotype. There were four balanced and 12 unbalanced translocations previously unreported in ALL with t(9;22). The t(2;7)(p11;p13) and der(18)t(8;18)(q11.2;p11.2) were seen in two cases each, and have never before been reported in haematological malignancy. All but four patients were treated on front-line Cancer and Leukaemia Group B clinical protocols. The presence of -7 as a sole secondary abnormality was associated with a lower complete remission (CR) rate (P = 0.004), while the presence of > or =3 aberrations was associated with a higher CR rate (P = 0.009) and +der(22)t(9;22) with a higher cumulative incidence of relapse (P = 0.02). It will be of interest to see if newly diagnosed t(9;22)-positive adult ALL patients with these and other secondary aberrations respond differently to treatment regimens that include imatinib mesylate.

Predictive immunophenotypes: disease-related profile in chronic fatigue syndrome.

BACKGROUND: There is a growing body of evidence supporting the theory that problems with immune function play an important role in chronic fatigue syndrome (CFS). METHODS: We studied 90 CFS cases and 50 healthy controls from two different areas of upstate New York to determine whether there were differences in the absolute number and pattern of natural killer (NK) and cytotoxic T-cell phenotypes between CFS cases and healthy controls in the two regions. One group was from a small town where a cluster of cases existed; the other was from a large metropolitan area where there was not a known cluster. RESULTS: The number of CD56+CD3+CD8+ and CD56+CD3+CD8- cells in cases from the two areas were both significantly elevated over that of controls from the metropolitan area (P < 0.03). The number of CD56+CD3-CD8+ and CD56+CD3-CD8- cells was significantly reduced in the two case groups compared to that of controls from the metropolitan area (P = 0.04). However, controls who were from the same town as the cluster cases had numbers of CD56+CD3+CD8+, CD56+CD3+CD8-, and CD56+CD3-CD8- cells that were more like that of cases than controls. Only the number of CD56+CD3-CD8+ cells (an NK cell subset) was significantly different in cases versus controls from the cluster area (P = 0.022). CONCLUSIONS: These data suggest that differences in controls from cluster and noncluster areas may be responsible for some of the inconsistencies in results from other studies. Furthermore, they suggest the possibility that NK cell function may play an important role in preventing the development of CFS in individuals who live in a community where a cluster of cases have been identified.

Lineage specific treatment of adult patients with acute lymphoblastic leukemia in first remission with anti-B4-blocked ricin or high-dose cytarabine: Cancer and Leukemia Group B Study 9311.

BACKGROUND: Anti-B4-blocked ricin is an immunotoxin comprised of an anti-CD19 murine monoclonal antibody (B4) conjugated to blocked ricin, which has cytotoxic activity in patients with lymphoid malignancies. METHODS: Adults with untreated acute lymphoblastic leukemia (ALL) were treated with a previously developed and tested chemotherapeutic regimen. Patients with CD19 positive ALL were given anti-B4-blocked ricin as 2 7-day continuous infusions 1 week apart. Patients with CD19 negative ALL received high-dose cytarabine. Serial polymerase chain reaction (PCR) assays of BCR-ABL, immunoglobulin heavy chain (IGH), and T-cell receptor (TCR) genes were used to measure the impact of lineage specific intensification treatment on minimal residual disease. RESULTS: Eighty-two adults were enrolled, and 78 were eligible. The median age was 34 years (range, 17-81 years). Sixty-six patients (85%) achieved complete remission. Forty-six patients received the anti-B4-blocked ricin, which generally was well tolerated; 80% were able to receive both courses. The most common toxicity was asymptomatic transient elevation of liver function tests in 72% of patients. Lymphopenia occurred in 46% of patients. Two patients developed antibodies to the anti-B4-blocked ricin. Molecular monitoring before and after the experimental course of intensification did not show a consistent change in the number of leukemia cells remaining, and the immediate posttreatment PCR studies did not correlate with remission duration. CONCLUSIONS: Intensification therapy with anti-B4-blocked ricin is feasible for patients with CD19 positive ALL, although there is little evidence of an additional clinical benefit from the anti-B4-blocked ricin. Cancer 2003;97:1471-80.

A software method for color compensation.

When two or more fluorochromes are measured simultaneously, every detector sees some fluorescence from every fluorochrome. Spectral compensation is the process of removing the undesired overlap of signal. Although very successful for two and three fluorochromes, the general practice of adjusting instrument compensation becomes increasingly inadequate and unforgiving as the number of fluorochromes increases. When data are collected uncompensated, software compensation provides the flexibility of setting correct compensation every time for every sample. Software methods do have problems. The linearization assumptions made by the software algorithms may be more or less in error. Binning effects become more of a problem with increasing numbers of compensated parameters. This explanatory unit also contains protocols that illustrate the process of software compensation utilizing matrix algebra that provides for elements of all possible PMT detection combinations. Although details are limited to four colors, the principles described can be applied to any desired number. When two or more fluorochromes are measured simultaneously, every detector sees some fluorescence from every fluorochrome.

Report from a workshop on multianalyte microsphere assays.

Multiplexed assays using fluorescent microspheres is an exciting technique that has been gaining popularity among researchers, particularly those in the public health field. Part of its popularity is due to its flexibility, as both immunoassays and oligonucleotide hybridization assays can be developed on this platform. This report summarizes a workshop held by the Centers for Disease Control and Prevention that discussed issues surrounding these assays and the Luminex 100 xMAP instrument. Topics included instrumentation, assay design, sample matrix and volume, quality control, and development of commercial applications.

Emerging technology and future developments in flow cytometry.

The authors' view of the future of flow cytometry is based on a belief that the single most important aspect flow cytometry offers to the investigator is high-speed interrogation of correlated measurements on a cell-by-cell basis. Over the next several years, an enormous increase in the capabilities of cytometry in general, and flow cytometry in particular, is likely to occur. A brief description of some of those capabilities is the subject of this article.

Breast epithelium procurement from stereotactic core biopsy washings: flow cytometry-sorted cell count analysis.

PURPOSE: Molecular studies of breast lesions have been constrained by difficulties in procuring adequate tissues for analyses. Standard procedures are restricted to larger, palpable masses or the use of paraffin-embedded materials, precluding facile procurement of fresh specimens of early lesions. We describe a study to determine the yield and characteristics of sorted cell populations retrieved in core needle biopsy specimen rinses from a spectrum of breast lesions. EXPERIMENTAL DESIGN: Cells from 114 consecutive stereotactic core biopsies of mammographic lesions released into saline washes were submitted for flow cytometric analysis. For each specimen, epithelial cells were separated from stromal and blood tissue based on the presence of cytokeratin 8 and 18 markers. Epithelial cell yields based on pathological diagnoses of the biopsy specimen, patient age, and mammographic appearance of the lesion were determined. RESULTS: Biopsies containing malignant lesions yielded significantly higher numbers of cells than were obtained from benign lesion biopsies. Significantly greater cell counts were observed from lesions from women age 50 or above compared with those of younger women. Mammographic density surrounding the biopsy site, the mammographic appearance of the lesion, and the number of cores taken at the time of biopsy appeared to have little effect on the yield of epithelial cells. CONCLUSIONS: We demonstrate the use of flow cytometric sorting of stereotactic core needle biopsy washes from lesions spanning the spectrum of breast pathology to obtain epithelial cells in sufficient numbers to meet the requirements of a variety of molecular and genetic analyses.

Characterization of murine macrophages.

This unit describes the phenotypic characterization of macrophages through the use of fluorescence-labeled monoclonal antibodies (MAbs) that have specificity for certain extracellular membrane proteins expressed by macrophages. Although macrophages have no distinctive cell-surface antigen that allows for their enrichment, a specific set of markers can be used to distinguish macrophages from other cell types in a heterogeneous population of cells. The method can also be easily applied to cells from other sources, e.g., peritoneal exudates or spleen. Through the use of image or flow cytometry, these cells can be identified and (with flow cytometry) sorted out from a heterogeneous population for further culture or analysis.

Characterization of human monocytes/macrophages.

Human monocytes/macrophages display a variety of cell-surface determinants to which monoclonal antibodies (MAbs) have been produced. These MAbs can be used to characterize phenotypic profiles of monocytes/macrophages to gain insight into their developmental and activation status. The basic and alternate protocols in this unit describe flow cytometry methods for measuring the expression of membrane determinants using directly conjugated or unconjugated MAbs, respectively. Because cells of this lineage display characteristic membrane marker patterns, combinations of MAbs are used in three-color analysis to facilitate immunophenotypic characterization. Detailed information and commercial sources of fluorochrome-labeled MAbs are provided, and suggested combinations of these MAbs for three-color flow cytometry analysis of cell suspensions are discussed.