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PubMed1994

Characterization of the immunophenotype and functional properties of fibroblast-like synoviocytes in comparison to skin fibroblasts and umbilical vein endothelial cells.

We characterized the immunophenotype as well as functional properties--phagocytosis, the uptake of acetylated LDL, and the expression of HLA class II antigens, adhesion molecules, and cytokine mRNA--of fibroblast-like synoviocytes from rheumatoid arthritis synovium. Skin fibroblasts (FB) and umbilical vein endothelial cells (HUVEC) were studied in parallel. Cytofluorometric immunophenotyping by use of 84 mAb and 2 lectins and immunofluorescence microscopy indicated a high degree of homology between the three cell types. Only staining with mAb to von Willebrand factor (vWF) and CD31 and the lectin UEA-I appeared specific to HUVEC, whereas the mAb 5B5 to prolyl 4-hydroxylase that has been reported to be specific to FB stained HUVEC as well as synoviocytes and FB. All of the cells phagocytosed fluorescent latex beads of 1.7 and 2.6 microns in size. The uptake of acetylated LDL could be shown by HUVEC and, surprisingly, by synoviocytes, but not by FB. The induction of HLA-DR, -DP, and -DQ by IFN-gamma on the three cell types showed a similar dose-dependence. The upregulation of ICAM-1 by IL-1 alpha, TNF-alpha, and IFN-gamma appeared similar, whereas the induction of VCAM-1 by IL-1 alpha, IL-4, TNF-alpha, and IFN-gamma showed differences between the three cell types. ELAM-1 was expressed only on HUVEC after treatment with IL-1 alpha and TNF-alpha. The capacity of the cells to produce cytokines was studied at the level of mRNA by reverse transcription and PCR. All three cell types expressed the mRNA of IL-1 alpha, IL-6, IL-8, GM-CSF, and TGF-beta 1 spontaneously or after LPS stimulation, but never TNF-alpha mRNA. Our results indicate a high degree of relationship between the three cell types. In contrast to HUVEC, none of the markers and functional properties investigated appear specific to FB. Therefore, the issue of the origin of fibroblast-like synoviocytes and the role of vascular endothelial cells in the inflamed synovium is discussed.

Antibodies, Monoclonal↗

PubMed1993

Correlation of morphological FAB classification and immunophenotyping: value in recognition of morphological, cytochemical and immunological characteristics of mixed leukaemias.

Correlation between the FAB classification and immunophenotype was studied in 169 consecutive adult patients with acute leukaemia (AL). The lineage of leukaemic cells could be determined in the majority of cases, whereas 3 patients (1.8%) remained unclassified. In 22 out of 71 patients (31%) with acute myeloid leukaemia (AML) FAB M1 and M2 types, and in 5 out of 16 patients (31%) with chronic myeloid leukaemia (CML) in myeloid blast crisis, leukaemic cells did not express myeloid lineage-related markers, indicating asynchronous expression of cell markers in a substantial proportion of patients. Flow cytometric two-colour immunofluorescence revealed mixed AL immunophenotype in 6 out of 169 patients (3.4%). This group included five CD2+AML (5% of AML tested) and one undifferentiated AL expressing CD10(CALLA), CDw65(VIM-2). The former group included FAB M1, M2, M3 and M4 forms of AML with a single cell population, and an AML M2 patient with both cytochemically and immunologically two separate populations of leukaemic cells. This further illustrates the heterogeneity of the target cell(s) for leukaemogenesis and the level of differentiation of AML cells. However, there was no difference in the treatment response and the remission duration between AML patients and patients with mixed phenotype AML.

Acute Disease↗

PubMed2000

Fine-needle aspiration of granulocytic sarcomas: a morphologic and immunophenotypic study of seven cases.

Granulocytic sarcoma is an uncommon extramedullary, solid tumor of myeloid cells. Only rarely has this entity been diagnosed by fine-needle aspiration (FNA) cytology. This report encompasses the cytologic findings of FNAs from seven patients with granulocytic sarcomas, including four male and three female patients with a mean age of 52 years (range, 12 to 77 years). The aspirates were obtained from skin or subcutaneous tissue (four cases), testis (one case), posterior ileum (one case), lymph node (one case), and abdominal washing (one case). Morphology of the aspirates varied from well-differentiated to poorly differentiated cells showing little or no evidence of myeloid differentiation. Thorough search for evidence of myeloid differentiation and a high index of suspicion of granulocytic sarcoma are of paramount importance. In three cases, flow cytometric and immunocytochemical studies were applied to the FNA materials to confirm the myeloid lineage of the cells and the diagnosis. In the other four cases more than one site was involved by the tumor; once the diagnosis of granulocytic sarcoma was established with a biopsy, the FNA sufficed to confirm the diagnosis at another location. This study demonstrates that FNA cytology in conjunction with appropriate immunophenotyping can provide an accurate diagnosis of granulocytic sarcoma. Fine-needle aspiration can reduce the need for surgical intervention when combined with immunophenotypic studies and when additional anatomic sites are involved.

Adolescent↗

PubMed1999

Hodgkin's and non-Hodgkin's lymphoma: spectrum of morphologic and immunophenotypic overlap.

Immunoperoxidase markers are useful and often essential in distinguishing among lymphocyte-predominant Hodgkin's lymphoma, T-cell-rich B-cell lymphoma, and lymphocyte-rich classic Hodgkin's lymphoma. However, it is becoming increasingly clear that these "entities" are closely related clonal B-lineage neoplasms that may intertransform and/or coexist. We hypothesized that, just as there are cases with morphologic overlap, there would also be immunophenotypic overlap that would be found when a series of such cases is studied in detail. Eight cases of lymphocyte predominant Hodgkin's lymphoma, eight cases of lymphocyte-rich classic Hodgkin's lymphoma, seven cases of T-cell-rich B-cell lymphoma, and four cases of large B-cell lymphoma with focal features of T-cell-rich B-cell lymphoma were examined by the immunoperoxidase technique for expression of CD3, CD15, CD30, CD20, CD57, epithelial membrane antigen, and Epstein-Barr virus latent membrane protein (EBV LMP). All eight of the lymphocyte-predominant Hodgkin's lymphoma cases had CD20+ lymphocytic and histiocytic cells and CD57+ rosettes; however, in two cases, occasional lymphocytic and histiocytic cells were also weakly positive for CD15, CD30, and EBV LMP. Among the eight lymphocyte-rich classic Hodgkin's lymphoma cases, CD15+ Reed-Sternberg (R-S) cells were found in seven; however, in three of these cases rare rosettes of CD57+ cells surrounded the R-S or lacunar cells. In one case of large B-cell lymphoma the malignant cells resembled R-S cells and were CD20+, EBV LMP+, CD30+, CD15-, and surrounded by rosettes of CD57+ T cells. The majority of the cases exhibited the "expected" immunophenotypic patterns; however, the exceptional cases that were found serve to confirm the interrelationship among these clonal B-lineage neoplasms.

Adolescent↗

PubMed2004

Immunophenotypical characteristics of permanent cultures of lymphoid cells from Papio hamadryas and Macaca arctoides.

Immunophenotypical characteristics of primate cells were studied by enzyme immunoassay and flow cytofluorometry using a panel of monoclonal antibodies to human B- and T-lymphocyte antigens. Specific features of immunophenotype of cultured cells were detected. Simian lymphoid cultures consist of a mixture of B- and T-cells with mosaic antigenic structure expressing markers of B and T cell specificity.

Animals↗

PubMed2000

Solitary fibrous tumors are immunophenotypically distinct from mesothelioma(s).

INTRODUCTION: Solitary fibrous tumor is a soft tissue tissue tumor of unknown histogenesis. Based upon histologic similarities and CD-34 expression, it has been suggested that these neoplasms bear some relationship to mesothelioma, and may represent its extra-pleural equivalent. METHODS: In order to further investigate this possible relationship, we examined a series of five dermal and five extra-cutaneous solitary fibrous tumors with antibodies directed against the mesothelial markers calretinin and HBME-1. RESULTS: All the lesions failed to stain with the antibodies tested. This suggests that despite some similar histologic and immunophenotypic features, these lesions are not immunophenotypically identical. Mesotheliomas are CD-34(+), calretinin(+), HBME-1(+), while solitary fibrous tumors are CD-34(+), calretinin(-), HBME-1(-). CONCLUSIONS: The histogenesis of solitary fibrous tumor remains elusive. It is unlikely that tumor location or tumor de-differentiation accounts for the dichotomous staining properties, as these neoplasms show a similarly benign histologic appearance regardless of location.

Adult↗

PubMed2000

Immunophenotyping of peripheral blood, ranges of serum chemistries and clinical hematology values of healthy chimpanzees (Pan troglodytes).

This paper presents clinical chemistry, hematology and immunophenotyping data from 102 chimpanzees over a 2-year period. The groupings were: 3 years or less, 4-7 years, and 8 + years. These data are intended to augment formerly published information on these parameters and to serve as a concise reference guide for primate veterinarians and researchers for whom these data may be useful. This study has larger samplings than previously published data and more panel constituents by immunophenotyping.

Animals↗

PubMed2000

Immunophenotypic and genotypic markers of follicular center cell neoplasia in diffuse large B-cell lymphomas.

Diffuse large B-cell lymphomas (DLBCL) are a biologically and clinically heterogeneous entity. Although some DLBCL represent transformation of follicular lymphomas (FL), the proportion that is of follicular center cell (FCC) origin remains uncertain. Immunophenotypic and genotypic markers used to suggest a FCC origin for a lymphoma (bcl-6 and CD10 expression, lack of CD138 expression, bcl-2 rearrangements [R]) or to subdivide DLBCL (bcl-2 expression, bcl-6 R) were therefore investigated in 22 FL and 44 DLBCL using paraffin section immunostains and Southern blot/polymerase chain reaction analysis. All FL tested were bcl-6+ (19) and CD138- (22) with 16/19 also bcl-2 and CD10+ (classic phenotype), one bcl2+, CD10- (grade III) and two bcl2-, CD10+ (grade II or III). Bcl-2R was identified in 4/5 FL-GrI, 3/6 FL-GrII, and 1/3 FL-GrIII. Bcl-6R was found in 0/5, 2/4, and 0/3 FL, respectively. All but 3/41 DLBCL were bcl-6+ with 17/37 also bcl-2+ and CD10+. Three of these cases were also CD138+. Twelve bcl-6+ cases were bcl-2+, CD10-, six bcl-2-, CD10+, and two bcl-2-, CD10-. The three bcl-6- cases were bcl-2+, CD138- and two were CD10+. Bcl-2R was identified in 5/27 DLBCL with 4/5 bcl-2+, 3/4 tested CD10+ and 4/4 bcl-6+. Bcl-6R was identified in 7/26 including three with a classic FL phenotype. The vast majority of DLBCL in this study have an immunophenotype that supports a FCC origin. Although the proportion of DLBCL that co-expressed bcl-6, CD10 and bcl-2 was lower than for the FL, absence of bcl-2 or CD10 may be associated with higher grade FL It is also possible that bcl-6 expression is not completely specific for a FCC origin. Only a minority of cases suggested postfollicular differentiation. Only a minority of DLBCL show bcl-2R, suggesting that many have a different molecular pathogenesis than most low-grade FL. Bcl-6R did not exclude a FCC origin.

B-Lymphocytes↗

PubMed1997

Sezary cell-like leukemia with atypical immunophenotype.

We describe the clinical and laboratory features of an unusual case with Sezary cell-like leukemia. Clinical manifestations were: anemia (Hb 9.4 g/dl), severe thrombocytopenia (5 x 10(9)/l), lymphocytosis (43 x 10(9)/l) and splenomegaly. There was no lymphadenopathy, hepatomegaly or skin lesions. Bone marrow trephine showed diffuse infiltration by atypical lymphoid cells. By ultrastructural analysis the cells were small to medium-size lymphocytes with nuclear features identical to Sezary cells. Immunophenotyping showed that most peripheral blood mononuclear cells were negative with B lymphoid, myeloid, and stem cell-associated markers and were also negative with most T lymphoid markers (CD2, CD4, membrane/cytoplasmic CD3, CD5 and CD8). However, they were positive with CD38 (70%), CD7 (25%) and TIA-2 (25%). Molecular analysis showed a clonal rearrangement of the TCR beta and gamma chain genes. The patient was initially treated with vincristine, doxorubicin and asparaginase and then with six cycles of CHOP, achieving a complete remission and remaining free of disease 22 months from diagnosis. Aberrant immunophenotypes are not frequent in primary T cell leukemias. This is the first case of a rare type of T cell neoplasm, Sezary cell-like leukemia, in which cells lacked most of the T cell-associated antigens.

Adult↗

PubMed2003

Diagnostic role and prognostic significance of a simplified immunophenotypic classification of mature B cell chronic lymphoid leukemias.

We verified the diagnostic and prognostic role of a simplified immunophenotypic classification (IC) in a series of 258 patients (M/F: 1.4; median age: 64 years; median follow-up: 64 months; 75 deaths) with mature B cell lymphoid leukemias (MBC-LL) for whom no histopathological diagnosis was available because of minimal or no lymph node involvement. The IC was based on the reactivity of three pivotal immunophenotypic markers: CD5, CD23 and SIg intensity. On the basis of different expression patterns, we identified four diagnostic clusters (C) characterized by distinct clinico-biological features and different prognoses: C1 (149 patients) identified most classical B cell chronic lymphocytic leukemias (CLL-type cluster; SIg(dim)/CD5+/CD23+); C2, 38 patients whose clinico-hematological characteristics were intermediate between C1 and C3 (CLL-variant cluster; SIg(bright)/CD5+/CD23+/-or SIg(dim)/CD5-/-/CD23 indifferent); C3 (16 patients) most situations consistent with mantle cell lymphoma in leukemic phase (MCL-type cluster; SIg(bright)/CD5+/CD23-); and C4, 55 cases, most of whom were consistent with leukemic phase lymphoplasmacytic/splenic marginal zone lymphomas (LP/S-type cluster; SIg(bright)/CD5-/+/CD23 indifferent). At univariate survival analysis, prognosis worsened from C1 to C4, C2 and C3 (P = 0.0001), and this was maintained at multivariate analysis (P = 0.006), together with CD11c expression (P = 0.0043), age at diagnosis (cut-off 70 years; P = 0.0008) and platelet count (cut-off 140 x 10(9)/l; P = 0.0034). Besides recognising the two well-known situations of classic B-CLL and MCL, our IC identified situations with distinct prognostic and/or clinical behaviors.

Adult↗

PubMed2004

In vitro drug-resistance profile in infant acute lymphoblastic leukemia in relation to age, MLL rearrangements and immunophenotype.

Acute lymphoblastic leukemia (ALL) in infants under 1 year is strongly associated with translocations involving 11q23 (MLL gene), CD10-negative B-lineage (proB) immunophenotype, and poor outcome. The present study analyses the relationship between age, MLL rearrangements, proB-lineage, and in vitro drug resistance determined using the MTT assay. Compared to 425 children aged over 1 year with common/preB (c/preB) ALL, the 44 infants were highly resistant to steroids (for prednisolone (PRED) more than 580-fold, P=0.001) and L-asparaginase (L-ASP) (12-fold, P=0.001), but more sensitive to cytarabine (AraC) (1.9-fold, P=0.001) and 2-chlorodeoxyadenosine (2-CdA) (1.7-fold, P<0.001). No differences were found for vincristine, anthracyclines, thiopurines, epipodophyllotoxines, or 4-hydroperoxy (HOO)-ifosfamide. ProB ALL of all ages had a profile similar to infant ALL when compared with the group of c/preB ALL: relatively more resistant to L-ASP and PRED (and in addition thiopurines), and more sensitive to AraC and 2-CdA. Age was not related to cellular drug resistance within the proB ALL group (<1 year, n=32, vs >/=1 year, n=19), nor within the MLL-rearranged ALL (<1 year, n=34, vs >/=1 year, n=8). The translocation t(4;11)(q21;q23)-positive ALL cases were more resistant to PRED (>7.4-fold, P=0.033) and 4-HOO-ifosfamide (4.4-fold, P=0.006) than those with other 11q23 abnormalities. The expression of P-glycoprotein, multidrug-resistance protein, and lung-resistance protein (LRP) was not higher in infants compared to older c/preB ALL patients, but LRP was higher in proB ALL and MLL-rearranged ALL of all ages. In conclusion, infants with ALL appear to have a distinct in vitro resistance profile with the proB immunophenotype being of importance. The role of MLL cannot be excluded, with the t(4;11) being of special significance, while age appears to play a smaller role.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2005

Drug-induced immunophenotypic modulation in childhood ALL: implications for minimal residual disease detection.

Assessment of minimal residual disease (MRD) by flow cytometry is considered to be based on the reproducibility of the leukemic immunophenotype detected at diagnosis. However, we previously noticed modulation of surface antigen expression in acute lymphoblastic leukemia (ALL) during the early treatment. Hence, we investigated this in 30 children with B-cell precursor ALL consecutively enrolled in the AIEOP-BFM ALL 2000 protocol. Quantitative expression of seven antigens useful in MRD monitoring was studied at diagnosis and compared to that measured at different time points of remission induction therapy. Downmodulation in the expression of CD10 and CD34 occurred at follow-up. By contrast, upmodulation of CD19, CD20, CD45RA, and CD11a was observed, while the expression of CD58 remained stable. Despite this, we could unambiguously discriminate leukemic cells from normal residual B cells. This holds true when bone marrow (BM) samples from similarly treated T-ALL patients, but not from healthy donors, were used as reference. Our results indicate that immunophenotypic modulation occurs in ALL during the early phases of BFM-type protocols. However, the accuracy of MRD detection by flow cytometry seems not negatively affected if adequate analysis protocols are employed. Investigators should take this phenomenon into account in order to avoid pitfalls in flow cytometric MRD studies.

Antigens, CD↗

PubMed2002

Primary cutaneous marginal zone B-cell lymphoma: a clinical, histopathological, immunophenotypic and molecular genetic study of 22 cases.

BACKGROUND: Primary cutaneous marginal zone B-cell lymphoma (MZCL) has recently been described. Differentiation from follicular centre cell lymphomas and lymphocytomas is often difficult due to insufficient experience and a lack of large series of patients. OBJECTIVES: To characterize primary cutaneous MZCL better, we report clinical, histopathological, immunophenotypic and molecular genetics features in a series of 22 patients. METHODS: All patients were treated and followed up at the same institution. Diagnosis of MZCL was based on the World Health Organization classification criteria. All samples were routinely tested with a wide panel of monoclonal antibodies. DNA was extracted from every sample following standard methods. IgH rearrangement and t(14;18)(q32;q21) studies were performed in all samples. RESULTS: Twenty-two patients (20 men, two women; mean age 50 years, range 24-77) were included. The mean follow-up was 43 months. Seventy per cent of patients presented with characteristic skin lesions on the trunk or extremities, consisting of deep red to violaceous infiltrated plaques, nodules or tumours frequently surrounded by diffuse or annular erythema. Four patients presented with lesions on the head and neck area. Two patients had disseminated skin lesions. The main histopathological features were non-epidermotropic, dense lymphocytic infiltrates mainly distributed in a nodular pattern. Adnexal involvement was usually present, with eventual formation of lymphoepithelial complexes. Cytologically, the infiltrate was polymorphous with marginal zone B cells and B-monocytoid cells. Blastoid CD30+ cells were often observed. Colonized reactive germinal centres and lymphoplasmocytoid differentiation were frequently present. Neoplastic cells were CD20+, CD79a+, CD5- and CD10-. Monotypic expression of light chains was observed in 18 cases (13 kappa; five lambda). Clonal IgH rearrangements were detected in 14 cases. The bcl-2 mutation t(14;18)(q32;q21) was demonstrated in two cases. Most patients were treated with local radiotherapy. Complete response rate with this approach was 100%. Six patients (27%) had skin recurrences from 6 months to 8 years after first treatment. Five patients (23%) had extracutaneous involvement. Two of them had a large cell transformation and one died of lymphoma. Three of four patients with head and neck presentation developed extracutaneous disease. CONCLUSIONS: MZCL appears to be a well recognizable entity, clinically, histologically and immunophenotypically. Although prognosis is generally good, the disease has potential for skin as well as extracutaneous recurrences. Large cell transformation and head and neck presentation may be associated with a worse prognosis.

Adult↗

PubMed1997

Immunophenotypic and ultrastructural study in peripheral blood neutrophil granulocytes following bone marrow transplantation.

Neutrophil studies after bone marrow transplantation (BMT) describe chemotactic and phagocytotic alterations and dyshaemopoiesis. Neutrophil granulocytes (NG) in peripheral blood after BMT were analysed in 28 patients. 14 patients (six receiving GM-CSF) underwent autologous BMT and 14 underwent allogeneic BMT. Immunophenotypic and electron microscopic studies were performed during post-BMT granulopoietic regeneration. Results were compared with NG from 15 healthy bone marrow donors (control group A) and from six patients receiving intensive chemotherapy before autologous BMT (control group B). A significant increase in CD15 and a decrease in 8C7 antigen expression was observed in peripheral blood NG from BMT patients compared with controls A. MPO-7 in NG after BMT did not differ from control group A. Autologous BMT patients showed a lower percentage of NG expressing 13F6, 31D8 and CD16 (Leu 11a) than allogeneic BMT patients, and a significant decrease in 8C7 antigen expression compared with patients receiving intensive chemotherapy. Ultrastructurally, a marked decrease of azurophilic granules was observed in NG from BMT patients compared with control groups A and B. These data indicate that repopulation after BMT was made by phenotypically less mature NG with dysgranulopoietic features. Differences between autologous and allogeneic BMT patients may be partly related to GM-CSF usage. In conclusion, NG present immunophenotypic and ultrastructural changes after BMT which may be involved in abnormal NG response against bacterial infections, although further investigation is needed.

Adolescent↗

PubMed1998

Immunophenotypic analysis enables the correct prediction of t(8;21) in acute myeloid leukaemia.

Immunophenotypic findings from 14 patients affected by acute myeloid leukaemia (AML) with t(8;21) were compared to those obtained from 79 AML patients with normal or other aberrant karyotypes. Classic lineage markers, adhesion molecules, surface enzymes, stem-cell-related antigens and HLA-DR were investigated. Following evaluation by the Mann-Whitney test, we found that t(8;21) AMLs showed a significantly higher expression of CD19, CD34, CD56, CD45RA and CD54. Conversely, blasts from patients in the control group significantly expressed higher levels of CD45RO, CD33, CD36, CD11b and CD14. In order to split the data at the best cut-off point to achieve the most homogeneous subset with regard to cytogenetic pattern, i.e. t(8;21) or not, the CART (Classification and Regression Trees) method was applied. In the univariate analysis by CART, statistically significant differences were found when CD19 was dichotomized at 10%, CD34 at 37%, CD45RA at 84%, CD54 at 21%, CD56 at 12%, CD36 at 14%, CD45RO at 25%, CD11b at 18% and CD14 at 12%. Once cut-off points were established by CART, we applied the logistic regression model to establish which combination of two or more antigens was most predictive for t(8;21). The combination CD19-CD34 at the cut-off points indicated above correctly classified 92/93 cases (98.9%). The addition of any other antigen combination to the CD19/CD34 model failed to improve the level of prediction. We conclude that AML with t(8;21) displays an exclusive immunophenotype that is highly predictive of the cytogenetic pattern.

Acute Disease↗

PubMed1999

Functional lymphocyte immunophenotypes observed in thalassaemia and haemophilia patients receiving current blood product preparations.

Immune abnormalities have been reported in recipients of cellular and plasma blood products. To document the effect of current transfusion practices, we performed ex vivo lymphocyte immunophenotypic studies on patients with thalassaemia major who had received multiple (leucocyte-depleted) transfusions and patients with haemophilia A and B who had received heat viral-inactivated factor concentrates. Patients with thalassaemia major showed a significant lymphocytosis, with mainly B-cell changes consistent with ongoing B-cell stimulation associated with chronic exposure to red cell antigens. Reduced T-cell IL-2Ralpha expression would be consistent with inhibition by desferrioxamine chelation therapy. In contrast, patients with haemophilia showed predominantly T-cell changes. Patients with haemophilia A showed significantly elevated activated CD8+ cytotoxic T lymphocytes whereas those with haemophilia B showed an increase in CD8+CD11adim and CD4+CD45RA+ suppressor T cells. Several of the immune abnormalities found may be due to the presence of cytokines not removed by leucocyte filtration or destroyed by factor concentrate production (e.g. TGF-beta) causing a T-helper-2-like response. The extensive lymphocyte characterization in this study has not previously been performed and has enabled a closer examination of the functional lymphocyte immunophenotypes seen in patients treated according to current transfusion practices.

Adolescent↗

PubMed2001

Two consecutive immunophenotypic switches in a child with immunogenotypically stable acute leukaemia.

A 12-year-old girl presented with a CD33+ precursor B-acute lymphoblastic leukaemia (ALL) and seemed to respond well to ALL treatment. However, 2 weeks after diagnosis her leucocyte count rose rapidly with a predominance of myeloid blasts with M5b morphology and CD19+ myeloid immunophenotype. Acute myeloid leukaemia (AML) treatment was started and remission was achieved after one course of chemotherapy; the AML treatment was continued for 6 months. Two months after cessation of chemotherapy, the patient developed a bone marrow relapse, this time with an undifferentiated blast morphology and a precursor B immunophenotype. Molecular analysis of the immunoglobulin and T-cell receptor genes showed several clonal gene rearrangements at diagnosis: two IGH, two IGK and two TCRD gene rearrangements. All rearrangements were also detected during the AML phase of the disease, suggesting a phenotypic shift of the same leukaemia. At relapse, 8 months later, all rearrangements were preserved except for one TCRD (Vdelta2-Ddelta3) rearrangement. The first phenotypic shift in the genotypically stable leukaemia was remarkably fast. The most probable explanation for our observations is an oncogenic event in an undifferentiated haematopoietic progenitor clone, with a highly versatile phenotype.

Acute Disease↗

PubMed2003

Outcome prediction by immunophenotypic minimal residual disease detection in adult T-cell acute lymphoblastic leukaemia.

Flow-cytometric detection of minimal residual disease (MRD) identifies patients with high relapse risk in childhood acute lymphoblastic leukaemia (ALL). We studied the efficacy of this method in adult T-ALL treated with the Italian co-operative GIMEMA (Gruppo Italiano Malattie Ematologiche dell'Adulto) LAL0496 protocol. Bone marrow samples from 53 patients were taken at fixed treatment time points and MRD was analysed using a leukaemia-specific immunophenotype (cytoplasmic-CD3/nuclear-terminal desoxynucleotidyl transferase). The median follow-up was 17 months (range 3-61) and a median of 4.5 analyses/patient was performed (range 3-12). Six out of 53 (11.3%) patients were refractory to treatment, 30/53 (56.6%) relapsed and 17/53 (32.1%) remain in continuous complete remission. The probability of relapse at 2 years for MRD-positive patients at preconsolidation was 81.5%vs 38.9% for MRD-negative patients (P = 0.00078). This risk was still 54.5% for MRD-positive vs 15.8% for MRD-negative patients pre-third reinduction (P = 0.0098) and 50.0% for MRD-positive vs 16.4% for MRD-negative patients pre-sixth reinduction (P = 0.032). The relapse-predicting value of MRD did not depend on features at diagnosis such as age, sex and leucocyte count. Our data suggest that immunophenotypic MRD monitoring in the first year of treatment is a useful outcome predictor for adult T-ALL patients.

Flow Cytometry↗