Peripheral selection of V delta 1+ cells with restricted T cell receptor delta gene junctional repertoire in the peripheral blood of healthy donors.

To characterize the T cell receptor (TCR) repertoire expressed by the V delta 1+ gamma/delta T cell population, we have studied the V delta 1-J delta 1 junctional sequences from peripheral blood samples of healthy donors. We show that, surprisingly, this repertoire is restricted in most healthy adults, with a donor-specific and relatively stable pattern, whereas this repertoire remains unrestricted in infants, and is similar to that of thymocytes. These data contrast with the general assumption that the junctional repertoire of V delta 1+ gamma/delta T cells is extensive, and strongly suggest that peripheral recruitment of V delta 1+ cells bearing particular TCR occurs in humans during the postnatal stage.

Analysis of minimal residual disease by Ig/TCR gene rearrangements: guidelines for interpretation of real-time quantitative PCR data.

Most modern treatment protocols for acute lymphoblastic leukaemia (ALL) include the analysis of minimal residual disease (MRD). To ensure comparable MRD results between different MRD-polymerase chain reaction (PCR) laboratories, standardization and quality control are essential. The European Study Group on MRD detection in ALL (ESG-MRD-ALL), consisting of 30 MRD-PCR laboratories worldwide, has developed guidelines for the interpretation of real-time quantitative PCR-based MRD data. The application of these guidelines ensures identical interpretation of MRD data between different laboratories of the same MRD-based clinical protocol. Furthermore, the ESG-MRD-ALL guidelines will facilitate the comparison of MRD data obtained in different treatment protocols, including those with new drugs.

Powerful strategy for polymerase chain reaction-based clonality assessment in T-cell malignancies Report of the BIOMED-2 Concerted Action BHM4 CT98-3936.

Polymerase chain reaction (PCR) assessment of clonal T-cell receptor (TCR) and immunoglobulin (Ig) gene rearrangements is an important diagnostic tool in mature T-cell neoplasms. However, lack of standardized primers and PCR protocols has hampered comparability of data in previous clonality studies. To obtain reference values for Ig/TCR rearrangement patterns, 19 European laboratories investigated 188 T-cell malignancies belonging to five World Health Organization-defined entities. The TCR/Ig spectrum of each sample was analyzed in duplicate in two different laboratories using the standardized BIOMED-2 PCR multiplex tubes accompanied by international pathology panel review. TCR clonality was detected in 99% (143/145) of all definite cases of T-cell prolymphocytic leukemia, T-cell large granular lymphocytic leukemia, peripheral T-cell lymphoma (unspecified) and angioimmunoblastic T-cell lymphoma (AILT), whereas nine of 43 anaplastic large cell lymphomas did not show clonal TCR rearrangements. Combined use of TCRB and TCRG genes revealed two or more clonal signals in 95% of all TCR clonal cases. Ig clonality was mostly restricted to AILT. Our study indicates that the BIOMED-2 multiplex PCR tubes provide a powerful strategy for clonality assessment in T-cell malignancies assisting the firm diagnosis of T-cell neoplasms. The detected TCR gene rearrangements can also be used as PCR targets for monitoring of minimal residual disease.

Significantly improved PCR-based clonality testing in B-cell malignancies by use of multiple immunoglobulin gene targets. Report of the BIOMED-2 Concerted Action BHM4-CT98-3936.

Polymerase chain reaction (PCR) assessment of clonal immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements is an important diagnostic tool in mature B-cell neoplasms. However, lack of standardized PCR protocols resulting in a high level of false negativity has hampered comparability of data in previous clonality studies. In order to address these problems, 22 European laboratories investigated the Ig/TCR rearrangement patterns as well as t(14;18) and t(11;14) translocations of 369 B-cell malignancies belonging to five WHO-defined entities using the standardized BIOMED-2 multiplex PCR tubes accompanied by international pathology panel review. B-cell clonality was detected by combined use of the IGH and IGK multiplex PCR assays in all 260 definitive cases of B-cell chronic lymphocytic leukemia (n=56), mantle cell lymphoma (n=54), marginal zone lymphoma (n=41) and follicular lymphoma (n=109). Two of 109 cases of diffuse large B-cell lymphoma showed no detectable clonal marker. The use of these techniques to assign cell lineage should be treated with caution as additional clonal TCR gene rearrangements were frequently detected in all disease categories. Our study indicates that the BIOMED-2 multiplex PCR assays provide a powerful strategy for clonality assessment in B-cell malignancies resulting in high Ig clonality detection rates particularly when IGH and IGK strategies are combined.

Acute lymphoblastic leukemia relapsing after first-line pediatric-inspired therapy: a retrospective GRAALL study.

The outcome of adult patients with Philadelphia chromosome-negative acute lymphoblastic leukemia (Ph- ALL) relapsing after pediatric-inspired front-line therapy is ill known. Here 229 relapsing Ph- ALL younger adults (18-63 years) treated within the Group for Research on Adult Acute Lymphoblastic Leukemia (GRAALL)-2003/-2005 trials were considered. Salvage regimens consisted of potentially curative therapies in 194 cases, low-intensity therapies in 21, allogeneic stem cell transplant (allo-SCT) in 6 and best supportive care in 8. Overall, 77 patients received allo-SCT after relapse. The median follow-up was 3.1 years. A second complete remission (CR2) was achieved in 121 patients (53%). In multivariate analysis, only younger age <45 years (P=0.008) and CR1 duration ⩾18 months (P=0.009) predicted CR2. Overall survival (OS) at 2 and 5 years was 19.3% (14-24%) and 13.3% (8-18%), respectively. In CR2 patients, disease-free survival (DFS) at 2 and 5 years was 29.0% (21-38%) and 25% (17-33%). In multivariate analysis, CR1 duration ⩾18 months and allo-SCT after relapse were associated with longer DFS (P<0.009 and P=0.004, respectively) and longer OS (P=0.004 and P<0.0001, respectively). In conclusion, although younger adults relapsing after pediatric-inspired ALL therapies retain a poor outcome, some of them may be cured if CR1 duration ⩾18 months and if allo-SCT can be performed in CR2. New therapies are definitely needed for these patients.

Rapid, multifluorescent TCRG Vgamma and Jgamma typing: application to T cell acute lymphoblastic leukemia and to the detection of minor clonal populations.

Detection of clonal T cell receptor gamma (TCRG) gene rearrangements by PCR is widely used in both the diagnostic assessment of lymphoproliferative disorders and the follow-up of acute lymphoblastic leukaemia (ALL), when residual positivity in excess of 10(-3) at morphological complete remission is increasingly recognised to be an independent marker of poor prognosis. This is largely based on specific detection of V-J rearrangements from childhood cases. We describe rapid, multifluorescent Vgamma and Jgamma PCR typing of multiplex amplified diagnostic samples, as applied to 46 T-ALL. These strategies allow selected analysis of appropriate cases, immediate identification of Vgamma and Jgamma segments in over 95% of alleles, improved resolution and precision sizing and a sensitivity of detection at the 10(-2)-10(-3) level. We demonstrate preferential V-J combinations but no difference in V-J usage between children and adults, nor between SIL-TAL1-negative and -positive cases. A combination of fluorescent multiplex and Vgamma-Jgamma-specific monoplex follow-up, as described here, will allow detection of both significant clonal evolution and of the diagnostic clone at a level of prognostic significance, by techniques which can readily be applied to large-scale prospective studies for which real-time analysis is required.

IgH DJ rearrangements within T-ALL correlate with cCD79a expression, an immature/TCRgammadelta phenotype and absence of IL7Ralpha/CD127 expression.

cCD79a and IgH VDJ/DJ rearrangements are considered to be relatively specific for B lymphoid precursors. We looked for both in cCD3+, CD7+, CD19- T-ALLs classified by TCR status into alphabeta or gammadelta/immature (IM) lineages, with individualization of HOX11L2+ T-ALLs since they represent an intermediate alphabeta/gammadelta category. cCD79a was expressed at low levels in 47% of T-ALL and was most frequent in IMgamma T-ALLs. IgH rearrangements were common in gammadelta/IM (45%) and HOX11L2+ (35%) T-ALLs compared to HOX11L2-negative cases (3%; P<0.001). CD127 (IL7Ralpha) expression was also more common in the gammadelta/IM lineage but its expression was virtually mutually exclusive of IgH rearrangement. Low-level cCD79a expression alone should therefore not be interpreted as evidence of B lineage affiliation in immature leukemias. gammadelta/IM lineage T-ALLs potentially include two distinct categories: predominantly IgH+, cCD79a+, CD127- cases which retain gammadelta and B lymphoid potential and IgH-, cCD79a-, CD127+ cases with restricted T lineage potential.

Correlation between CD4 cell counts and cellular and plasma viral load in HIV-1-seropositive individuals.

We conducted a study of 152 HIV-1-seropositive individuals in order to evaluate the possible correlations between the isolation of HIV from peripheral blood mononuclear cells or from plasma and CD4 cell counts. HIV was isolated from only 36% of plasma samples, and the isolation rate was closely related to CD4 cell counts, increasing gradually from 0% in subjects with greater than 800 x 10(6)/l CD4 cells to 88% in those with less than 100 x 10(6)/l CD4 cells. In contrast, HIV was isolated from 92% of cell samples (99% in subjects with less than 900 x 10(6)/l CD4 cells, 46% in those with CD4 counts greater than or equal to 900 x 10(6)/l). Since most cell samples were positive, a scoring method was designed to quantify the cellular viral load. The results obtained demonstrated that the cellular viral load was closely related to CD4 counts. We also found that the cellular viral load was higher in subjects with either positive plasma isolation or positive p24 antigenaemia. The measurement of the cellular viral load by this scoring method appears to be useful for the management of HIV-seropositive individuals and for the evaluation of therapeutic trials.

Consistency of routine measurements of CD4+, CD8+ peripheral blood lymphocytes.

In order to evaluate the reliability of CD4 and CD8 T lymphocyte counts in large scale studies, a quality control study was performed in 12 French laboratories. CD4 and CD8 counts, assessed by various haematological and immunological techniques, were compared in order to assess possible differences between the laboratories and the techniques used. Our data showed that (a) the consistency of CD4 measurements was satisfactory since the between-laboratory coefficient of variation for absolute CD4 cell numbers above 200/mm3 was around 15% instead of 5-10% for all laboratories but one; (b) the major sources of variability arose from the use of automatic devices in the two-step measurement procedure: immunophenotyping and haematological counting. These data suggest that multicentre assays of CD4 and CD8 counts result in some increase in their variability. Nevertheless the results of large multicentric trials can be extrapolated with confidence in the routine care of HIV+ patients. Together, the results justified the involvement of several experienced laboratories in a clinical trial of HIV-related disease.

Comparison of Epstein-Barr virus markers in Reed-Sternberg cells in adult Hodgkin's disease tissues from an industrialized and a developing country.

The link between Hodgkin's disease (HD) and Epstein-Barr virus (EBV) is well documented in childhood and here the same hypothesis has been examined in adults, by comparing cases from an industrialized and a developing country. In this study the prevalence of EBV markers in nodal lesions of adult HD were compared in 21 patients from France (Fr) and 25 from Algeria (Al), all clinically staged during 1990-1992. Median age was 29 years. Histologic subtypes included lymphocytic predominance (LP) Fr 1; nodular sclerosis (NS) Fr 16, Al 16; mixed cellularity (MC) Fr 4, Al 9. EBV markers examined included expression of latent membrane protein (LMP) in Reed-Sternberg and Hodgkin cells (RSC) by immunochemistry; EBV-DNA and -RNA in situ hybridization (ISH); EBV-DNA by polymerase chain reaction (PCR). Results showed that RSC were LMP-positive in 4 (2 NS, 2 MC) French and 7 (3 NS, 4 MC) Algerian. All LMP+ cases were also positive for EBV DNA-RNA ISH. ISH was positive in RSC of 33% of the French and 72% of Algerian patients (p < 0.02). The positivity was more frequent in MC (77%) than in other histologic types (45%). The EBV genome was detected by PCR on DNA extracted from frozen samples in 84% of Fr and 95% of Al patients (100% of MC and 86% of other histologic types). Conclusion. The discrepancy between PCR and ISH results may be due to the lesser sensitivity of the ISH technique, or, alternatively, to the presence of EBV in the lymphoid cells surrounding RSC.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantification of red blood cell fragmentation: usefulness of heating cells and of automatic counting devices.

Spontaneous red blood cell (RBC) fragmentation occurs in some membrane erythropathies like hereditary elliptocytosis (HE); this phenomenon is produced in normal RBC by heating at 49 degrees C, but not at temperatures below this limit; fragmentation is usually quantified by counting the number of fragments/1000 RBC under light microscopic examination. The present work demonstrates: i) that enumeration of fragments is performed more precisely with an automatic blood cells counter on the 'platelet' channel; and ii) that heating at 48 degrees C enhances the fragmentation of RBC when they have a severe disruption of skeletal lattice, like in HE.

Flow cytometry and IG/TCR quantitative PCR for minimal residual disease quantitation in acute lymphoblastic leukemia: a French multicenter prospective study on behalf of the FRALLE, EORTC and GRAALL.

Minimal residual disease (MRD) quantification is widely used for therapeutic stratification in pediatric acute lymphoblastic leukemia (ALL). A robust, reproducible, sensitivity of at least 0.01% has been achieved for IG/TCR clonal rearrangements using allele-specific quantitative PCR (IG/TCR-QPCR) within the EuroMRD consortium. Whether multiparameter flow cytometry (MFC) can reach such inter-center performance in ALL MRD monitoring remains unclear. In a multicenter study, MRD was measured prospectively on 598 follow-up bone marrow samples from 102 high-risk children and 136 adult ALL patients, using IG/TCR-QPCR and 4/5 color MFC. At diagnosis, all 238 patients (100%) had at least one suitable MRD marker with 0.01% sensitivity, including 205/238 samples (86%) by using IG/TCR-QPCR and 223/238 samples (94%) by using MFC. QPCR and MFC were evaluable in 495/598 (83%) samples. Qualitative results (<0.01% or ≥0.01%) concurred in 96% of samples and overall positivity (including <0.01% and nonquantifiable positivity) was concurrent in 84%. MRD values ≥0.01% correlated highly (r(2)=0.87) and 69% clustered within half-a-log(10). QPCR and MFC can therefore be comparable if properly standardized, and are highly complementary. MFC strategies will benefit from a concerted approach, as does molecular MRD monitoring, and will contribute significantly to the achievement of 100% MRD informativity in adult and pediatric ALL.

EuroClonality/BIOMED-2 guidelines for interpretation and reporting of Ig/TCR clonality testing in suspected lymphoproliferations.

PCR-based immunoglobulin (Ig)/T-cell receptor (TCR) clonality testing in suspected lymphoproliferations has largely been standardized and has consequently become technically feasible in a routine diagnostic setting. Standardization of the pre-analytical and post-analytical phases is now essential to prevent misinterpretation and incorrect conclusions derived from clonality data. As clonality testing is not a quantitative assay, but rather concerns recognition of molecular patterns, guidelines for reliable interpretation and reporting are mandatory. Here, the EuroClonality (BIOMED-2) consortium summarizes important pre- and post-analytical aspects of clonality testing, provides guidelines for interpretation of clonality testing results, and presents a uniform way to report the results of the Ig/TCR assays. Starting from an immunobiological concept, two levels to report Ig/TCR profiles are discerned: the technical description of individual (multiplex) PCR reactions and the overall molecular conclusion for B and T cells. Collectively, the EuroClonality (BIOMED-2) guidelines and consensus reporting system should help to improve the general performance level of clonality assessment and interpretation, which will directly impact on routine clinical management (standardized best-practice) in patients with suspected lymphoproliferations.

PAX5 mutations occur frequently in adult B-cell progenitor acute lymphoblastic leukemia and PAX5 haploinsufficiency is associated with BCR-ABL1 and TCF3-PBX1 fusion genes: a GRAALL study.

Adult and child B-cell progenitor acute lymphoblastic leukemia (BCP-ALL) differ in terms of incidence and prognosis. These disparities are mainly due to the molecular abnormalities associated with these two clinical entities. A genome-wide analysis using oligo SNP arrays recently demonstrated that PAX5 (paired-box domain 5) is the main target of somatic mutations in childhood BCP-ALL being altered in 38.9% of the cases. We report here the most extensive analysis of alterations of PAX5 coding sequence in 117 adult BCP-ALL patients in the unique clinical protocol GRAALL-2003/GRAAPH-2003. Our study demonstrates that PAX5 is mutated in 34% of adult BCP-ALL, mutations being partial or complete deletion, partial or complete amplification, point mutation or fusion gene. PAX5 alterations are heterogeneous consisting in complete loss in 17%, focal deletions in 10%, point mutations in 7% and translocations in 1% of the cases. PAX5 complete loss and PAX5 point mutations differ. PAX5 complete loss seems to be a secondary event and is significantly associated with BCR-ABL1 or TCF3-PBX1 fusion genes and a lower white blood cell count.

[Normal and pathological laboratory results: how to define "normal" serum iron levels? (author's transl)]. / Le normal et le pathologique au laboratoire: comment définir la " normalité " de la sidérémie?

Apart from technical problems, the difficulty in defining "normal" biological laboratory values lies in the choice of reference population and in the way of expressing the results. This is illustrated by a study of 181 healthy, non-anaemic and non-microcytic adults of both sexes (108 men and 73 women) and of comparable age-range. All subjects had venous blood samples taken under the same conditions to determine serum iron levels, total iron binding capacity and percent transferrin saturation (PTS). In 12 of the women these laboratory tests were done before and after one month of supplmentary iron administration. The values obtained in women were significantly lower than in men. The differences, however, were reduced when iron stores, as measured by percent transferrin saturation, were quasi-normal (i.e. PTS greater than 0,16 or 0,19). They disappeared in women who had received supplementary iron. Normal laboratory results are usually expressed as mean values +/- two standard deviations, the range being supposed to include 95% of normal subjects. But this only applies to the values obtained when dispersion is low. When dispersion is high, the percentile method should be preferred, as it expresses the biological findings without reference to an assumed Gaussian distribution.

Actuarial rate of clinical and biological progression in a cohort of 250 HIV-1-seropositive subjects. Laennec HIV Study Group.

This study was undertaken to define the risk of AIDS in a cohort of 250 HIV-seropositive patients identified by their clinical and biological status. All patients were enrolled between October 1985 and March 1988. They were classified according to clinical classes A, asymptomatic (n = 97); B, lymphadenopathic (n = 123); and C, AIDS-related complex, (n = 30). Also as CD4 cell stages 1 (CD4 greater than or equal to 600/microliters; n = 126); 2 (CD4 less than 600 and greater than or equal to 300/microliters; n = 83); and 3 (CD4 less than 300/microliters; n = 41); and serum p24 antigen positive (n = 48) or negative (n = 202). All patients were evaluated every 3-6 months, until AIDS development or April 1989: 29 cases of AIDS occurred during the follow-up period. The risk of AIDS in class C is very high (64% at 2 years) compared with the 3-year risk of classes A (13%) and B (25%). On the other hand the three CD4 stages have significantly different prognosis (stage 1 6%; stage 2 22%; and stage 3 89%; P less than 10(-2]. Antigen p24 negative and positive patients have also different prognosis (18% and 53%; P less than 10(-4]. Interestingly, p24 antigen conserved its prognostic value in stage 2 (positive 37%, negative 16%) while stages 1 are at low risk of AIDS and stages 3 at high risk whatever their p24 antigen status. We have also identified the risk of becoming stage 3 and/or p24 antigen positive in p24 antigen negative patients at stages 1 and 2 (respectively, 18% and 47%). This classification should serve to design randomized trials better with experimental drugs with earlier end-points than AIDS onset.

Autoreactive cytotoxicity in HIV-infected individuals.

A possible role for autoimmunity in the pathogenesis of HIV infection has been suggested, based upon the certain degree of homology shared by HIV gp41 and MHC class II molecules. A number of humoral markers of autoimmunity have since been found in seropositive subjects. We have evaluated the cellular autoreactive response in HIV-infected individuals. Our study demonstrates the existence of a cytolytic activity, present in seropositive but not in seronegative subjects. This activity is mediated by CD3+ T cells, which only occasionally express the CD8 or the CD4 surface markers. Effector cells do not appear to exert their activity in a MHC-restricted fashion, since allogeneic target cells could also be killed, recovered from allogeneic seropositive as well as from seronegative subjects. Several types of target cells were lysed: T cell blasts and Epstein-Barr virus (EBV) transformed B cells, suggesting that the target antigen is common to at least these two cell types. The fact that cells from seronegative individuals were lysed argues against the recognition of an HIV-specific antigen. The nature of the target determinants and the identity of the effector cells are discussed.