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Low-grade lymphoma of mucosa-associated tissue in the parotid gland: a case report of fine-needle aspiration cytology diagnosis using flow cytometric immunophenotyping.

A 66-year-old woman with Sjögren's syndrome for 7 years presented with an enlarged right parotid gland. The left parotid gland, which showed myoepithelial sialadenitis (MESA), had been resected 4 years earlier. A fine-needle aspiration (FNA) biopsy of the right parotid gland was performed. Examination of the smears revealed cells of intermediate size with a round-to-irregular nuclear outline and distinct pale cytoplasm intermixed with small mature round lymphocytes. The chromatin was slightly paler and less clumped than in small mature lymphocytes. A small inconspicuous nucleolus was seen in most of the cells. Flow cytometry immunophenotyping performed on the FNA biopsy material showed a monoclonal population of B cells with kappa light chain restriction. The cytomorphology coupled with the immunophenotyping study in this clinical context suggested the diagnosis of low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT). Extensive staging work-up revealed no evidence of disseminated disease. The right parotid gland was surgically excised. Histology and gene rearrangement studies confirmed the cytologic diagnosis. To our knowledge, this is the first description of a low-grade lymphoma of MALT in a salivary gland to be diagnosed by FNA.

Aged↗

Natural killer cell lymphoma of the small intestine: diagnosis by flow cytometric immunophenotyping of paracentesis fluid.

Natural killer (NK) cell lymphoma is a mass-forming neoplasm of putative NK cell lineage that typically appears in extranodal locations and has the following immunophenotype: CD2 positive, surface CD3 negative, cytoplasmic CD3 positive, and CD56 positive. We report a case of small-intestinal NK cell lymphoma that was originally diagnosed as an enteropathy-associated T-cell lymphoma based on paraffin immunohistochemistry. However, subsequent flow cytometric immunophenotyping of paracentesis fluid resulted in the correct diagnosis. We describe the case to illustrate the usefulness of this technique, which has not previously been described in such a case.

Adult↗

DNA ploidy, proliferative activities, and immunophenotype of malignant lymphoma: application of flow cytometry.

BACKGROUND: To explore the flow cytometric diagnosis of malignant lymphoma, we examined the deoxyribonucleic acid (DNA) ploidy, proliferative activities, and immunophenotype of surgical biopsy- and fine-needle aspiration (FNA)-derived materials. Our goal was to determine the possibility of making a diagnosis of malignant lymphoma by flow cytometric analysis of FNA-derived materials. METHODS: The DNA ploidy and proliferative indices including the percentage of S-phase fraction (SPF), G2 + M fraction (G2M), and Ki-67-positive fraction (Ki-67) were analyzed on the fresh materials from 84 consecutive patients with suspected malignant lymphoma. Flow cytometric analysis of surface antigens was simultaneously performed. Fourteen of the patients underwent FNA and subsequent surgical biopsy of the same lymph nodes for flow cytometric analysis. RESULTS: The proliferative indices of intermediate-grade non-Hodgkin's lymphomas (NHL) (n = 28) and high-grade NHL (n = 23) were significantly higher than those of the reactive hyperplasia (n = 25). The total for SPF + G2M of 6% was a satisfactory threshold for differentiating these NHL from reactive hyperplasia (sensitivity of 84%, specificity of 88%, and accuracy of 86%). However, low-grade NHL (n = 3) and Hodgkin's lymphoma (HL, n = 5) could not be discriminated by employing this parameter. DNA aneuploidy was seen in 13 of the 28 intermediate-grade NHL and 8 of the 23 high-grade NHL, whereas it was not seen in 25 reactive hyperplasia, 3 low-grade NHL, and 5 HL. The percentage of CD19-positive cells in B-cell NHL or CD3-positive cells in T-cell NHL was significantly higher compared with those for reactive hyperplasia. The percentage of CD16 + CD56-positive cells in natural killer (NK) cell NHL was extremely high, with a mean of 91.8%. Flow cytometric results for FNA-derived materials showed excellent correlation with those for surgical biopsy-derived specimens. CONCLUSIONS: Analyses of DNA ploidy, proliferative activities, and immunophenotype by flow cytometry (FCM) are useful for diagnosing intermediate- and high-grade NHL. Fine-needle aspiration is a less invasive approach than surgical biopsy, and, when combined with FCM, it may have a place in the diagnosis of NHL.

Biopsy, Needle↗

Comprehensive review of adult acute myelogenous leukemia: cytomorphological, enzyme cytochemical, flow cytometric immunophenotypic, and cytogenetic findings.

This study reports findings from a retrospective, comprehensive review of 80 cases of adult AML in regard to cytomorphology, enzyme cytochemistry (EC), flow cytometric immunophenotyping (FCI), and chromosomal analysis. From this review, we conclude that diagnostically challenging cases can only be subtyped by combining the cytomorphology with EC, FCI, and subsequent cytogenetic results. This is particularly true in recognizing the hypogranular variant of AML,M3 (AML, M3m) and distinguishing it from other subtypes. Nonlineage expression of markers (CD1, CD2, CD4, CD5, CD7, and CD56) was nonspecific as to AML subtype. Of interest, CD2 coexpression in acute myelomonocytic leukemia with eosinophilia (M4-Eo) was exclusively associated with inversion of chromosome 16 (inv 16) and was not observed in the other M4-Eo's without inv16. We also recognized a previously undescribed M3m with CD56 coexpression, heightening awareness of this entity which needs to be distinguished from the unique subtype of CD56+ AML with otherwise similar immunophenotypic and morphologic characteristics. In addition, nonlineage expression of CD19 alone was exclusively associated with the cytogenetic finding of t (8;21) (q22; q22) and thus may represent a favorable prognostic indicator by FCI.

Adult↗

Utility of molecular genetic analysis for the diagnosis of neoplasia in morphologically and immunophenotypically equivocal hematolymphoid lesions.

The authors reviewed retrospectively the results of molecular genetic analysis of 175 hematolymphoid lesions to assess the diagnostic utility of genotyping (analysis for immunoglobulin or beta-chain T-cell receptor gene rearrangements). All cases had been genotyped, and most were also immunophenotyped. Cases were assigned to control (90 cases) or problem groups (85 cases), depending on the absence or presence respectively of diagnostic uncertainty remaining after conventional (morphologic and immunophenotypic) analysis. All control cases had unequivocal morphologic features of non-Hodgkin's lymphoma (NHL) and had appropriate lineage-specific gene rearrangements, but immunostaining was almost as sensitive in demonstrating phenotypes that were diagnostically abnormal as well as lineage-specifying. However, genotyping was clearly diagnostically useful in the problem cases, which included a heterogeneous mixture of nodal and extranodal biopsy specimens of malignant (mostly NHL) and benign lesions. Genotyping demonstrated the appropriate absence or presence of gene rearrangements in 58 of 81 problem cases (72%) ultimately diagnosed as benign or malignant respectively, excluding four cases of Hodgkin's disease; in 25 cases (31%) this was judged to be essential to diagnosis. In the remaining problem cases genotyping did not contribute positively to diagnosis, but in no case was genotyping misleading when cautiously interpreted with primary reliance on conventional analysis and with knowledge of known causes of potentially misleading results, both positive and negative. It is concluded that although genotyping is highly sensitive and specific for hematolymphoid neoplasia, it provides little or no benefit in cases that are unequivocally malignant by conventional analysis, in cases of suspected Hodgkin's disease (HD), or for the sole purpose of lineage assignment. However, in cases whose diagnosis is uncertain after conventional analysis, the high yield of useful information from genotyping with careful interpretation warrants its application.

Gene Rearrangement, B-Lymphocyte↗

The importance of surface immunoglobulin, mouse rosettes, and CD5 in the immunophenotyping of chronic lymphocytic leukemia and reactive lymphocytosis.

Peripheral blood from 167 B-chronic lymphocytic leukemia (B-CLL) and 119 reactive lymphocytosis (RLC) patients were analyzed to evaluate the immunophenotypic diagnostic value of mouse rosettes (M-rosette), and weak expression of monoclonal surface immunoglobulin (SIg). In B-CLL, 145 cases were M-rosette+ (86.83%), 135 surface immunoglobulin (SIg)+ (80.84%), and 117 M-rosette+ SIg+ (70.06%). Of 32 SIg- cases, 28 were M-rosette+; and of 22 M-rosette-cases, 18 were SIg+. By combining results of the two assays and accepting positivity of either one or both as sufficient for diagnosis, B-CLL was diagnosed in 163 cases (97.60%). CD5 was performed in 49 cases of the 167 with paired data for SIg and M-rosettes. By combining the results of the three assays and accepting positivity of any two or all three as sufficient for diagnosis, all 49 cases (100%) were diagnosed. Correlation analysis showed no significant association between M-rosette, SIg, and CD5 expression. The results demonstrate the independent expression of the three markers, and their complementary role in immunophenotyping B-CLL. In RLC, all 119 cases were T-lineage and SIg-, and 115 were M-rosette-, indicating the role of the two markers in differentiating B-CLL from RLC. Three of the four M-rosette+ T-RLC were subsequently diagnosed as B-CLL, suggesting the necessity of follow-up of such cases.

Adult↗

Primary central nervous system lymphomas. Immunophenotypic, virologic, and cytogenetic findings of three patients without immune defects.

BACKGROUND: Primary central nervous system (PCNS) lymphoma is a relatively rare disease, but an increasing incidence is reported. The Epstein-Barr virus (EBV), which is often found in lymphomas of immunocompromised patients, has been implicated in the development of lymphomas. Many cytogenetic analyses of nodal B cell lymphomas have been performed, but few studies on PCNS lymphomas have been reported. METHODS: The detection of EBV genome using the polymerase chain reaction (PCR) method and cytogenetic studies were performed, in addition to histopathologic and immunophenotypic approaches in biopsied tissue from three patients with PCNS lymphoma. Immunosuppressive states and exposure to mutagens were not clear in all patients. RESULTS: Histopathologic examination disclosed a diffuse type of malignant lymphoma in all patients. Immunophenotypic studies revealed B cell phenotype in all patients, two of whom showed positive reaction for CD5. The PCR method revealed no involvement of EBV genome in tumors in any patients. The cytogenetic study showed clonal chromosome abnormalities in all patients, and abnormalities of chromosome 1 (1q21), 6 (-6, 6q15 and 6q21), 7 (-7 and 7p15), and 14 (14q24 and 14q32) were prominent. The t(6;14)(q15;q32) observed in Patient 1 is the first case to be reported in human de novo lymphoma. CONCLUSIONS: These findings indicate that the causative role of EBV in PCNS lymphoma without immune defects is not clear. The cytogenetic findings were similar to those observed in nodal B-cell lymphoma, suggesting that the origin of PCNS lymphoma cells does not differ from nodal B cell lymphoma cells cytogenetically.

Aged↗

Non-Hodgkin's lymphoma of the sinonasal tract. A clinicopathologic and immunophenotypic study of 120 cases.

BACKGROUND: Non-Hodgkin's lymphomas (NHLs) of the sinonasal tract are uncommon neoplasms that can be morphologically difficult to distinguish from destructive nonneoplastic processes or other malignant neoplasms in this site. METHODS: From the files of the Otolaryngic Tumor Registry-Armed Forces Institute of Pathology from 1965 to 1992, 120 cases of NHL involving the sinonasal tract were selected for which clinical records and paraffin-embedded tissue blocks were available. The histologic features and immunophenotypic findings of each patient were examined, and follow-up data were obtained for 66 (55%). RESULTS: The ratio of males to females was 1.35:1, and the ages ranged from 3 to 94 years (median, 59 years). Sixty percent of the cases of NHL occurred in the patients' sixth to eighth decades of life. Clinical presentations varied according to histologic type. The low grade lymphomas presented with a nasal cavity or paranasal sinus mass associated with obstructive symptoms. The high grade lymphomas were more likely to present with aggressive signs and symptoms including nonhealing ulcer, cranial nerve manifestations, facial swelling, epistaxis, or pain. Of note, the high grade B-cell lymphomas tended to present with soft tissue or osseous destruction, particularly of the orbit with associated proptosis, whereas the T-cell lymphomas were associated with nasal septal perforation and/or destruction. Sites of disease included the nasal cavity, one or more paranasal sinuses, or multiple regions within the sinonasal tract. Of patients who received adequate follow-up, nodal and extranodal dissemination were identified in a limited number (n = 11). Nodal dissemination occurred in cervical and axillary lymph nodes. Extranodal sites of involvement included the larynx, skin, liver, uvula, kidney, breast, lacrimal gland, testis, and prostate gland. There was a wide spectrum of morphologic types of lymphoma, classified according to the Working Formulation. Immunophenotypic analysis on paraffin embedded tissue sections of all patients demonstrated a B-cell to T-cell ratio of 1.18:1. Treatment primarily included radiotherapy and chemotherapy. Follow-up information was available for 66 (55%) patients ranging from 1 to 16 years (median, 3 years). Of these 66 patients, 24 (36.4%) died of disease, 17 (25.7%) are alive without disease, 13 (19.7%) are alive with disease, and 12 (18.2%) are dead of unrelated or unknown causes. CONCLUSIONS: Non-Hodgkin's lymphomas of the sinonasal tract are heterogeneous diseases that can be clinically aggressive. The frequency of these lymphomas in the United States cannot be estimated accurately because all of our cases were of histologic slides submitted for consultations. There appears, however, to be a slight B-cell predominance in this population that previously has been observed, unlike in South America and Asia where the majority of cases have a T-cell phenotype.

Adolescent↗

Use of specimen mammography-guided FNA (fine-needle aspirates) for flow cytometric multiple marker analysis and immunophenotyping in breast cancer.

A pilot study of a novel translational research method to simultaneously assay multiple molecular markers and DNA in fine-needle aspirates (FNA) of mammographically detected breast lesions is described. Specimen mammography-guided 20-gauge FNAs obtained from 86 lesions and 22 areas of normal tissue were analyzed by multiparameter flow cytometry for DNA content, her2/neu, transforming growth factor alpha (TGF alpha), and the epithelial marker cytokeratin (CK) simultaneously. Epithelial cell her2/neu positivity was detected in 12 of 44 (27%) of invasive ductal carcinomas and 3 of 9 (33%) ductal carcinoma in situ (DCIS), 10 of 30 (33%) benign lesions, and 4 of 22 (18%) normal tissue aspirates. All lesions and normal tissue showed a similar positive rate for TGFalpha ranging from 61 to 76%. The CK(+)TGF alpha(-)her2/neu(+) immunophenotype was more frequently positive in aneuploid tumors (22%) than all other lesions (7%) (P < 0.05). Specimen mammography-guided FNAs provide fresh cells for flow cytometric multiple marker analysis and immunophenotyping of clinically occult breast lesions and normal tissue.

Adult↗

Evaluation of interphase fluorescence in situ hybridization for the t(14;18)(q32;q21) translocation in the diagnosis of follicular lymphoma on fine-needle aspirates: a comparison with flow cytometry immunophenotyping.

BACKGROUND: Diagnosing lymphoproliferative disorders on fine-needle aspiration (FNA) can be challenging due to variable cellularity and lack of architecture. Ancillary studies often are required for diagnosis. Follicular lymphoma (FL) is characterized by a monoclonal B-cell proliferation with coexpression of CD19/CD10 and a t(14;18)(q32;q21) reciprocal translocation, resulting in the immunoglobulin heavy chain/BCL-2 fusion gene. These features also can be found, with much lower frequency, in diffuse large B-cell lymphoma (DLBCL) of follicle center cell origin. The objective of the current study was to compare the accuracy in detecting FL and DLBCL of follicle center cell origin by interphase fluorescence in situ hybridization (I-FISH) versus flow cytometry immunophenotyping (FCM) on FNAs. METHODS: Concurrent testing by FISH for t(14;18)(q32;q21) and FCM was performed on 84 FNAs, including 40 FLs and 44 non-FLs (de novo DLBCLs, mantle cell lymphomas, small lymphocytic lymphomas/chronic lymphocytic leukemias [SLLs/CLLs], small B-cell lymphomas, and reactive lymphoid hyperplasias). The final diagnosis was rendered based on the combined information from cytomorphology, FCM, FISH, immunocytochemical staining for Ki-67, monoclonality for kappa and lambda light chains, and, if available, corresponding tissue biopsy, cytogenetic analysis, and polymerase chain reaction analysis. RESULTS: Among 40 FLs, FISH produced positive results for the t(14;18) translocation in 85.0%, negative results in 7.5%, and insufficient results in 7.5%; whereas, with FCM, 75% of cases exhibited a CD19-positive (CD19+)/CD10+ population (28 monoclonal, 2 nonclonal), 12.5% of cases exhibited a CD19+/CD10-negative population (3 monoclonal, 2 nonclonal), and 12.5% of cases were insufficient. All of nonclonal results from FCM and all of the insufficient results from FCM analysis exhibited unequivocal t(14;18) translocation by FISH. In contrast, the three negative results and the three insufficient results from FISH were monoclonal and CD19+/CD10+ on FCM. The results from FISH and FCM were concordant in 75% cases. Of 44 non-FLs, FISH produced positive results for the t(14;18) translocation in 5 DLBCLs and 2 SLLs/CLLs. The latter showed single fusion signals just above the cutoff level. All cases in the non-FL group that failed to show clonality or had insufficient results from FCM were DLBCLs. Among 17 DLBCLs, FISH detected a t(14;18) translocation in 29.4%, whereas FCM demonstrated a CD19+/CD10+ population in 23.5%. CONCLUSIONS: I-FISH for the t(14;18)(q32;q21) translocation provided high overall accuracy in detecting FLs on FNAs. This test can be used for diagnosing or monitoring FL on FNAs when cellularity is limited or when FCM results are noncontributory. For detecting a follicle center cell origin in DLBCLs, I-FISH for the t(14;18) translocation appeared to be slightly more sensitive than FCM for the CD19+/CD10+ immunophenotype.

Chromosomes, Human, Pair 14↗

A small-volume technique for simultaneous immunophenotyping and apoptosis detection in rat whole blood by four-color flow cytometry.

BACKGROUND: Cell permeabilization for the detection of intracellular molecules by flow cytometry is usually incompatible with whole blood. This article describes a new technique for the simultaneous detection of surface antigens and DNA content in rat whole blood. METHODS: In 20 microl of rat whole blood, DNA staining is obtained by permeabilization of cells using a standard red blood cell lysing reagent (Erythrolyse). Immunophenotyping and apoptosis detection by flow cytometry are achieved by using a combination of three surface markers (CD3, CD4, and CD8alpha) and a DNA binding dye (TO-PRO-3). RESULTS: After a 24-h incubation of whole blood with 1 microM dexamethasone, apoptotic lymphocytes were clearly distinguishable from normal lymphocytes by their reduced size and DNA content. The dexamethasone-induced percentage of apoptotic cells was 58.9 +/- 4.6 for CD4+ and 77.4 +/- 2.9 for CD8+ T cells, compared with 12.6 +/- 2.7 for CD4+ and 17.2 +/- 3.5 for CD8+ T cells in the absence of dexamethasone (data from 10 animals with duplicate samples). CONCLUSIONS: We have developed a new technique to permeabilize nucleated cells in microsamples of rat whole blood. The methodology allows simultaneous immunophenotyping and apoptosis detection in rat whole blood.

Animals↗

A new cytometric method for the immunophenotypic characterization of bone-derived human osteoclasts.

BACKGROUND: Osteoclast cell function relates to bone resorption. Isolation and characterization of these cells from in vivo sources remain difficult. The aim of this study was to show the feasibility of using flow cytometry to identify and characterize human mature osteoclasts obtained from bone tissues. METHODS: Bone femoral heads obtained as discarded surgical material were used. To check the nature of 121F(+) (a monoclonal antibody specific for human osteoclasts) cells by flow cytometry, we used laser scanning cytometry to analyze simultaneously the immunophenotype and DNA cell content of osteoclast-like cell-enriched bone samples. RESULTS: Results were compared with conventional morphologic and cytochemical studies. The percentage of cells that showed both cytochemical (tartrate-resistant acid phosphatase [TRAP](+)) and immunophenotypic (121F(+)) osteoclast-associated characteristics was very similar (12.5 +/- 6.2 versus 14.7 +/- 11.7; P = 0.46). Laser scanning cytometry showed that 121F(+) cells were bigger (P = 0.04) and they had a higher DNA cell content (P = 0.04) and more nuclei per cell (P = 0.04) than the 121F(-) cells present in the same sample. DISCUSSION: This study relied on the combined use of the 121F(+) antibody and different cytometry-based techniques to characterize the osteoclast populations from human bone.

Acid Phosphatase↗

Evaluation of a dual-color flow cytometry immunophenotyping panel in a multicenter quality assurance program.

A basic immunophenotyping panel that employed dual-color combinations of fluorescein isothiocyanate (FITC) and phycoerythrin (PE) conjugated monoclonal antibodies (mAb; FITC-CD45/PE-CD14, FITC-IgG1/PE-IgG2, FITC-CD3/PE-CD8, FITC-CD3/PE-CD4, FITC-CD3/PE-CD16 + PE-CD56, and PE-CD19) was utilized in a quality assurance program to determine whether the 4 laboratories participating in a multicenter AIDS study obtained similar lymphocyte subset percentage values for T cells, B cells, NK cells, and CD4+ and CD8+ T cells. Over a 1 1/2 year period, 78 shared peripheral blood specimens were prepared and analyzed in each laboratory. The CD45bright CD14- percentage for each specimen was used to correct that individual's lymphocyte subset values. Interlaboratory coefficients of variation (CV) for the human immunodeficiency virus type I (HIV) seronegative (n = 38) and HIV-seropositive (n = 40) specimens using this panel were < 3% for total T cells; < 5% for CD4+ T cells and CD8+ T cells; < or = 17% for B and NK cells; and < 8% for CD4T/CD8T ratios. The 6-tube basic immunophenotyping panel has several notable features: a) for clinical studies, it permits comprehensive evaluation of an individual's major lymphocyte subsets, i.e., T, B, NK, and CD4+ and CD8+ T cells; b) for interlaboratory proficiency testing programs, it allows the detection of differences among laboratories in measurements of several functionally distinct cell populations; and c) for within-sample quality assurance, it provides several quality control checks, including the lymphosum, i.e., the sum of an individual's corrected T+B+NK values, a sum that was generally 100 +/- 5% on the HIV-seronegative specimens analyzed in this study.

AIDS Serodiagnosis↗

Double-staining artefact observed in certain individuals during dual-colour immunophenotyping of lymphocytes by flow cytometry.

An unusual double-staining artefact has been repeatedly observed in certain individuals (both HIV-positive and healthy laboratory controls) during 2-colour immunophenotyping of lymphocytes by flow cytometry after red cell lysis. This artefact can falsely suggest co-expression of CD4 and CD8, as well as some of the other monoclonal antibody pairs commonly used in the typing of lymphocytes. It is caused by a serum factor associated with the ammonium-sulphate-precipitated and gamma-globulin fractions. It appears to be fairly common in the population (being found in 6 out of 105 of our healthy laboratory controls and in 42 out of 247 of our HIV-1 seropositive subjects); it may be genetically determined, but may be acquired in some. It is a potential source of error in lymphocyte immunophenotyping, which can be avoided by simple adjustments to the recommended techniques.

Antibodies, Monoclonal↗

Quality control in flow cytometry for diagnostic pathology: II. A conspectus of reference ranges for lymphocyte immunophenotyping.

Immunophenotyping, as many other clinical assays, is interpreted only in the context of reference values obtained from healthy control individuals. While the use of these reference values, or ranges, has been commonplace in the clinical flow cytometry laboratory for well over a decade, there has been little consensus in standardizing how these values should be obtained, analyzed, or expressed. This report reviews the variables to be considered in establishing reference ranges and statistical methods which can be used. Additionally, examples are given of previously published reference ranges for a variety of specimens often submitted for immunophenotyping.

Adolescent↗

Flow cytometric immunophenotyping of lymphocyte subsets in samples that contain a high proportion of non-lymphoid cells.

Flow cytometric (FCM) immunophenotyping of peripheral blood from thalassemia patients presents technical difficulties because of the high proportion of immature red cells. The combination of forward scatter (FSC) and side scatter (SSC) with fluorescence associated with human leukocyte antigen/monocyte antigen (CD45/CD14) was unable to identify the lymphocyte population in thalassemia patients; therefore, it was necessary to exclude immature red cells to analyze lymphocyte subsets in these patients. A simultaneous three-color FCM method was developed, with the basis that transferrin receptor (CD71) or glycophorin A (glyco A) is present on all immature red cells, but is not expressed on CD45 positive leukocytes. In this study, the lymphocyte population was identified by gating out unwanted cell populations using the FSC/CD71-fluorescein isothiocyanate (FITC), FSC/glyco A-FITC, or FSC/CD45-peridinin chlorophyll protein (PerCP) profiles. The CD71-FITC negative cells, glyco A-FITC negative cells, or CD45-PerCP positive cells were identified, then analyzed on the basis of FSC/SSC to allow any remaining non-lymphocyte cells in FSC/SSC gate to be excluded. The cells in FSC/SSC gate were then analyzed using other irrelevant two-color antibodies. Of the three gating strategies, CD45-PerCP and glyco A-FITC methods are better than the CD71-FITC gating method. Both methods markedly increase the purity of lymphocytes in the analysis gate. Either method is easy, straightforward, requires a six-tube set of reagent tubes, and provides a reliable method for immunophenotyping lymphocyte subsets in preparations containing a large percentage of non-lymphoid cells.

Adult↗

Immunophenotyping of congenital leukemia.

Congenital leukemia is a rare but well-documented disease in which a leukemic process is detected at birth or very shortly thereafter. An estimated 175-200 reports of congenital leukemia have appeared in the literature. The majority of the cases reported have not undergone thorough immunophenotyping, but rather have been assigned lineage based on cytochemical and morphological studies. Historically, a large proportion of congenital leukemias have been thought to be of the myeloid lineage, in contrast to pediatric leukemias in general, which are primarily lymphoid. The precise proportions of the lineage assignments may be distorted by the inclusion of cases of transient myeloproliferative disorders (TMD) as congenital leukemia. The immunophenotyping data available to date suggest that congenital leukemias are phenotypically heterogeneous, lacking any common distinguishing markers. The prognosis for congenital leukemias is usually poor if leukemoid reactive processes, such as TMD, are carefully excluded.

Cell Lineage↗

Iterative restaining as a pivotal tool for n-color immunophenotyping by slide-based cytometry.

AIM: Slide-based cytometry (SBC) allows to "ask a cell a second time." We used this tool for detailed immunophenotyping of peripheral blood leukocytes (PBLs). METHODS: PBLs primarily stained for CD-markers and DNA were immobilized on a glass slide and analyzed by laser scanning cytometry. Then, iterative restaining was applied for a second and a third analysis. Based on the cells' fixed location, analyses were merged on a single-cell level. RESULTS: We analyzed six virtual immunostainings by "recycling" the PE-channel for four CD-markers. CONCLUSION: Iterative restaining might prove to be a pivotal tool for n-color immunophenotyping exclusive to SBC concepts.

Antibodies↗