Improved outcome of allogeneic transplantation in older patients treated for myeloid malignancies using post transplantation cyclophosphamide and reduced duration of immune suppression

BACKGROUND

Allogeneic stem cell transplantation (alloSCT) offers curative potential for older patients with myeloid malignancies. We evaluated the efficacy and safety of alloSCT using post-transplantation cyclophosphamide (PTCy) in combination with a very short duration of immune suppression (IS) in this population.

METHODS

We retrospectively analyzed 92 consecutive patients aged 65 years and older who underwent an alloSCT for myeloid malignancies between February 2018 and December 2022 at our institution. Data on patient characteristics, treatment modalities, and outcomes were collected.

RESULTS

Ninety-two patients received an alloSCT with PTCy-based GVHD prophylaxis. The majority had minimal comorbidities and were diagnosed with acute myeloid leukemia (AML). Patients mostly received conditioning regimens with low to intermediate TCI scores. In 43% of patients, IS could be permanently stopped at day +90, resulting in a median time of IS of 2.93 months in high-risk patients. At a median follow-up of 21.3 months, the 1- and 2-year overall survival rates were 89% and 87%, respectively. Relapse-free survival rates were 88% and 84% at 1 and 2 years, respectively. The 1- and 2-year cumulative incidences of relapse were 8% and 13%, while transplant-related mortality (TRM) estimates were 9% at both time points. Acute GVHD grade 3-4 occurred in 7% within the first 180 days and severe chronic GVHD in 6% of patients. This all resulted in a 1- and 2-year graft versus host and relapse free survival (GRFS) of 74% and 70%, respectively.

CONCLUSION

AlloSCT using PTCy in combination with a short duration of IS in older patients with myeloid malignancies demonstrates favorable survival outcomes due to low relapse rates and a low TRM. The low incidence of relapse and acceptable rates of graft-versus-host disease suggest the efficacy and safety of this approach. Further studies are warranted to validate these findings and optimize transplant strategies for older patients with myeloid malignancies.

Benefits and risks of clofarabine in adult acute lymphoblastic leukemia investigated in depth by multi-state modeling

BACKGROUND

We recently reported results of the prospective, open-label HOVON-100 trial in 334 adult patients with acute lymphoblastic leukemia (ALL) randomized to first-line treatment with or without clofarabine (CLO). No improvement of event-free survival (EFS) was observed, while a higher proportion of patients receiving CLO obtained minimal residual disease (MRD) negativity.

AIM

In order to investigate the effects of CLO in more depth, two multi-state models were developed to identify why CLO did not show a long-term survival benefit despite more MRD-negativity.

METHODS

The first model evaluated the effect of CLO on going off-protocol (not due to refractory disease/relapse, completion or death) as a proxy of severe treatment-related toxicity, while the second model evaluated the effect of CLO on obtaining MRD negativity. The subsequent impact of these intermediate events on death or relapsed/refractory disease was assessed in both models.

RESULTS

Overall, patients receiving CLO went off-protocol more frequently than control patients (35/168 [21%] vs. 18/166 [11%], p = 0.019; HR 2.00 [1.13-3.52], p = 0.02), especially during maintenance (13/44 [30%] vs. 6/56 [11%]; HR 2.85 [95%CI 1.08-7.50], p = 0.035). Going off-protocol was, however, not associated with more relapse or death. Patients in the CLO arm showed a trend towards an increased rate of MRD-negativity compared with control patients (HR MRD-negativity: 1.35 [0.95-1.91], p = 0.10), which did not translate into a significant survival benefit.

CONCLUSION

We conclude that the intermediate states, i.e., going off-protocol and MRD-negativity, were affected by adding CLO, but these transitions were not associated with subsequent survival estimates, suggesting relatively modest antileukemic activity in ALL.

Autologous hematopoietic cell transplantation for T-cell prolymphocytic leukemia: a retrospective study on behalf of the Chronic Malignancies Working Party of the EBMT

Not available.

Allogeneic Stem Cell Transplantation in Patients >40 Years of Age With Acute Lymphoblastic Leukemia: Reduced Intensity Versus Myeloablative Conditioning

BACKGROUND

The outcome in older patients with acute lymphoblastic leukemia (ALL) remains unsatisfactory due to high relapse and nonrelapse mortality (NRM) rates. Allogeneic stem cell transplantation (alloHSCT) as postremission therapy has an important role in reducing relapse rate, albeit its application is limited in older adult patients due to alloHSCT-related morbidity and mortality. Reduced-intensity conditioning (RIC) alloHSCT has been developed as a less toxic conditioning regimen, but comparative studies with myeloablative conditioning (MAC) are limited in patients with ALL.

METHODS

In this retrospective study, RIC-alloHSCT (n = 111) was compared with MAC-alloHSCT (n = 77) in patients aged 41 to 65 y with ALL in first complete remission. MAC was predominantly applied by combining high-dose total body irradiation and cyclophosphamide, whereas RIC mainly consisted of fludarabine and 2 Gy total body irradiation.

RESULTS

Unadjusted overall survival was 54% (95% confidence interval [CI], 42%-65%) at 5 y in MAC recipients compared with 39% (95% CI, 29%-49%) in RIC recipients. Overall survival and relapse-free survival were not significantly associated with type of conditioning after adjusted for the covariates age, leukemia risk status at diagnosis, donor type, and donor and recipient gender combination. NRM was significantly lower after RIC (subdistribution hazard ratio: 0.41, 95% CI, 0.22-0.78; P  = 0.006), whereas relapse was significantly higher (subdistribution hazard ratio: 3.04, 95% CI, 1.71-5.40; P < 0.001).

CONCLUSIONS

Collectively, RIC-alloHSCT has resulted in less NRM, but it was also found to be associated with a significantly higher relapse rate. These results suggest that MAC-alloHSCT may provide a more effective type of consolidation therapy for the reduction of relapse and that RIC-alloHSCT may be restricted to patients at higher risk for NRM.

Other malignancies in the history of CLL: an international multicenter study conducted by ERIC, the European Research Initiative on CLL, in HARMONY

Background

Patients with chronic lymphocytic leukemia (CLL) have a higher risk of developing other malignancies (OMs) compared to the general population. However, the impact of CLL-related risk factors and CLL-directed treatment is still unclear and represents the focus of this work.

Methods

We conducted a retrospective international multicenter study to assess the incidence of OMs and detect potential risk factors in 19,705 patients with CLL, small lymphocytic lymphoma, or high-count CLL-like monoclonal B-cell lymphocytosis, diagnosed between 2000 and 2016. Data collection took place between October 2020 and March 2022.

Findings

In 129,254 years of follow-up after CLL diagnosis, 3513 OMs were diagnosed (27.2 OMs/1000 person-years). The most common hematological OMs were Richter transformation, myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Non-melanoma skin (NMSC) and prostate cancers were the most common solid tumors (STs).The only predictor for MDS and AML development was treatment with fludarabine and cyclophosphamide with/without rituximab (FC ± R) (OR = 3.7; 95% CI = 2.79-4.91; p < 0.001). STs were more frequent in males and patients with unmutated immunoglobulin heavy variable genes (OR = 1.77; 95% CI = 1.49-2.11; p < 0.001/OR = 1.89; 95% CI = 1.6-2.24; p < 0.001).CLL-directed treatment was associated with non-melanoma skin and prostate cancers (OR = 1.8; 95% CI = 1.36-2.41; p < 0.001/OR = 2.11; 95% CI = 1.12-3.97; p = 0.021). In contrast, breast cancers were more frequent in untreated patients (OR = 0.17; 95% CI = 0.08-0.33; p < 0.001).Patients with CLL and an OM had inferior overall survival (OS) than those without. AML and MDS conferred the worst OS (p < 0.001).

Interpretation

OMs in CLL impact on OS. Treatment for CLL increased the risk for AML/MDS, prostate cancer, and NMSC. FCR was associated with increased risk for AML/MDS.

Funding

AbbVie, and EU/EFPIAInnovative Medicines Initiative Joint Undertaking HARMONY grant n° 116026.

A phase 1b study of blinatumomab with the anti-programmed cell death (PD)-1 antibody AMG 404 in adults with relapsed/refractory (R/R) B-cell precursor acute lymphoblastic leukemia (ALL)

e19003

Background: Preclinical data indicate that anti-PD-1 agents can facilitate activity of bispecific T-cell engager (BiTE) molecules. Here we assess the combination of the anti-CD19 BiTE molecule blinatumomab with the anti-PD-1 antibody AMG 404 in adults with R/R ALL (NCT04524455). Methods: Eligible adults with R/R ALL (Ph+ disease included) received 2-5 treatment cycles. Each cycle was 42 days, consisting of 4 weeks of cIV blinatumomab and a 2-week treatment-free interval as per label. In Cohort 1, AMG 404 was dosed IV at 240 mg every 4 weeks (Q4W); first dose was Day (D) 11 of Cycle (C) 1. Primary endpoints were dose-limiting toxicities (DLTs) and other adverse events (AEs). Results: As of 20 Dec 2021, patients (pts) from Cohort 1 (n=8) had median age of 57 (range: 24-73) y, 6/8 male, 6/8 Caucasian, 1 with extramedullary disease (duodenum), 2 with prior blinatumomab, and a median of 5 (2-15) prior treatment lines. Two pts remain on study and 2 completed the study; 4 pts discontinued the study due to death (n=3) or consent withdrawn (n=1). No DLTs were reported for the 3 evaluable pts. Of the 5 pts not evaluable for DLTs, in C1, 4 had disease progression and 1 an unrelated fatal pneumonia. Treatment-related grade (Gr) ≥3 and/or serious AEs in all 8 pts included cytokine release syndrome (CRS) (1 pt Gr 2, 1 pt Gr 1 and 3), Gr 3 increases in ALT and AST, Gr 3 fever, Gr 3-4 neutropenia, Gr 4 neutropenia/Gr 3-4 thrombocytopenia (same pt), Gr 2 sensorimotor polyneuropathy, Gr 3 hypertension, Gr 3 encephalopathy, and in 1 pt Gr 3-4 decreases in white blood cells, lymphocytes, and neutrophils. One pt developed Gr 3 SARS-COV-2 pneumonia on C2D25, resolving without clinical sequelae. C3 start was delayed by 12 days but protocol treatment resumed uneventfully. All 3 DLT-evaluable pts had a complete response (CR) or CR with partial hematologic recovery (CRh), 2/3 without measurable residual disease (MRD), within 2 cycles; the 3rd pt had an MRD response at the end of C3. Preliminary pharmacokinetic results for the combination of blinatumomab and AMG 404 demonstrated that their exposures were consistent with those observed for each as monotherapy and did not indicate any drug-drug interactions. To date, all samples tested for anti-blinatumomab antibodies have been negative. Conclusions: In this ongoing phase 1b study, the combination of blinatumomab with AMG 404 was tolerated with a manageable safety profile. No DLTs were reported. Enrollment continues in Cohort 2 in which AMG 404 is dosed Q4W at 480 mg starting on C1D1, 48 hours prior to blinatumomab. Clinical trial information: NCT04524455. [Table: see text]

Effect of ruxolitinib on the oral mucosa of patients with steroid-refractory chronic Graft-versus-Host disease and oral involvement

BACKGROUND

Chronic Graft-versus-Host Disease (cGVHD) can impact quality of life, especially in patients with oral involvement. Half of the patients with cGVHD do not respond to first-line therapy with corticosteroids and calcineurin inhibitors. Ruxolitinib is effective in steroid-refractory (SR)-cGVHD cases, but the long-term effects of ruxolitinib on the oral mucosa are unknown.

OBJECTIVE(S)

This study aims to assess the effect of ruxolitinib on the oral mucosa of SR-cGVHD patients with oral involvement.

MATERIALS AND METHODS

An observational longitudinal patient study was conducted in 53 patients with SR-cGVHD and oral involvement who were treated with ruxolitinib. The baseline condition of the oral mucosa was compared to its condition at 4 and 12 weeks after starting ruxolitinib.

RESULTS

The overall response was 81% (43/53), with a complete response in 53% (28/53) and partial response in 28% (15/53) after 12 weeks (p < 0.001). Men and patients concurrently using immunosuppressive therapy responded better than women (p = 0.005) and patients with ruxolitinib monotherapy (p = 0.02), respectively. At a longer follow-up (median 20 months), oral symptoms were comparable to the 12-week symptoms (p = 0.78), regardless of ruxolitinib use (p = 0.83).

CONCLUSION

Ruxolitinib treatment of SR-cGVHD patients with oral involvement was associated with a significant response of the oral manifestations at 12 weeks.

CLINICAL RELEVANCE

The oral mucosa of SR-cGVHD patients is likely to improve after 4 and 12 weeks of ruxolitinib treatment. Symptom severity at baseline does not affect the response of the oral mucosa.

miR-181a is a novel player in the STAT3-mediated survival network of TCRαβ+ CD8+ T large granular lymphocyte leukemia

T-LGL cells arise as a consequence of chronic antigenic stimulation and inflammation and thrive because of constitutive activation of the STAT3 and ERK pathway. Notably, in 40% of patients, constitutive STAT3 activation is due to STAT3 activating mutations, whereas in 60% this is unknown. As miRNAs are amongst the most potent regulators in health and disease, we hypothesized that aberrant miRNA expression could contribute to dysregulation of these pathways. miRNA sequencing in T-LGL leukemia cases and aged-matched healthy control TEMRA cells revealed overexpression of miR-181a. Furthermore, geneset enrichment analysis (GSEA) of downregulated targets of miR-181a implicated involvement in regulating STAT3 and ERK1/2 pathways. Flow cytometric analyses showed increased SOCS3+ and DUSP6+ T-LGL cells upon miR-181a inhibition. In addition, miR-181a-transfected human CD8+ T cells showed increased basal STAT3 and ERK1/2 phosphorylation. By using TL1, a human T-LGL cell line, we could show that miR-181a is an actor in T-LGL leukemia, driving STAT3 activation by SOCS3 inhibition and ERK1/2 phosphorylation by DUSP6 inhibition and verified this mechanism in an independent cell line. In addition, miR-181a inhibition resulted in a higher sensitivity to FAS-mediated apoptosis. Collectively, our data show that miR-181a could be the missing link to explain why STAT3-unmutated patients show hyperactive STAT3.

Genomic arrays identify high-risk chronic lymphocytic leukemia with genomic complexity: a multi-center study

Complex karyotype (CK) identified by chromosome-banding analysis (CBA) has shown prognostic value in chronic lymphocytic leukemia (CLL). Genomic arrays offer high-resolution genome-wide detection of copy-number alterations (CNAs) and could therefore be well equipped to detect the presence of a CK. Current knowledge on genomic arrays in CLL is based on outcomes of single center studies, in which different cutoffs for CNA calling were used. To further determine the clinical utility of genomic arrays for CNA assessment in CLL diagnostics, we retrospectively analyzed 2293 arrays from 13 diagnostic laboratories according to established standards. CNAs were found outside regions captured by CLL FISH probes in 34% of patients, and several of them including gains of 8q, deletions of 9p and 18p (p<0.01) were linked to poor outcome after correction for multiple testing. Patients (n=972) could be divided in three distinct prognostic subgroups based on the number of CNAs. Only high genomic complexity (high-GC), defined as ≥5 CNAs emerged as an independent adverse prognosticator on multivariable analysis for time to first treatment (Hazard ratio: 2.15, 95% CI: 1.36-3.41; p=0.001) and overall survival (Hazard ratio: 2.54, 95% CI: 1.54-4.17; p<0.001; n=528). Lowering the size cutoff to 1 Mb in 647 patients did not significantly improve risk assessment. Genomic arrays detected more chromosomal abnormalities and performed at least as well in terms of risk stratification compared to simultaneous chromosome banding analysis as determined in 122 patients. Our findings highlight genomic array as an accurate tool for CLL risk stratification.

Proteomic markers with prognostic impact on outcome of chronic lymphocytic leukemia patients under chemo-immunotherapy: results from the HOVON 109 study

Despite recent identification of several prognostic markers, there is still a need for new prognostic parameters able to predict clinical outcome in chronic lymphocytic leukemia (CLL) patients. Here, we aimed to validate the prognostic ability of known (proteomic) markers measured pretreatment and to search for new proteomic markers that might be related to treatment response in CLL. To this end, baseline serum samples of 51 CLL patients treated with chemo-immunotherapy were analyzed for 360 proteomic markers, using Olink technology. Median event-free survival (EFS) was 23 months (range: 1.25-60.9). Patients with high levels of sCD23 (>11.27, p = 0.026), sCD27 (>11.03, p = 0.04), SPINT1 (>1.6, p = 0.001), and LY9 (>8.22, p = 0.0003) had a shorter EFS than those with marker levels below the median. The effect of sCD23 on EFS differed between immunoglobulin heavy chain variable gene-mutated and unmutated patients, with the shortest EFS for unmutated CLL patients with sCD23 levels above the median. Taken together, our results validate the prognostic impact of sCD23 and highlight SPINT1 and LY9 as possible promising markers for treatment response in CLL patients.

Consensus criteria for diagnosis, staging, and treatment response assessment of T-cell prolymphocytic leukemia

T-cell prolymphocytic leukemia (T-PLL) is a rare, mature T-cell neoplasm with a heterogeneous clinical course. With the advent of novel treatment options that will potentially change the management of patients with T-PLL, it has become necessary to produce consensus guidelines for the design and conduct of clinical trials. The T-PLL International Study group (TPLL-ISG) set out to define standardized criteria for diagnosis, treatment indication, and evaluation of response. These criteria will facilitate comparison of results from clinical trials in T-PLL, and will thus support clinical decision making, as well as the approval of new therapeutics by healthcare authorities.

Use of gene expression microarrays for the study of acute leukemia

Genetic lesions found in acute leukemia drive the pathology of the disease in addition to forming reliable classifications of prognosis. However, there is still a reasonable heterogeneity of response among cases with the same genetic lesion. Moreover, many leukemia cases have no detectable genetic marker and these cases have marked heterogeneity of response. How can we learn more about the genes and pathways involved with leukemogenesis and response in the midst of such complexity? Gene expression microarrays are experimental platforms that allow for the simultaneous evaluation of the thousands of mRNA transcripts (the 'transcriptome'). This technology has revolutionized the study of leukemia, giving insight into genes and pathways involved in disease response and the biology involved in specific translocations.

Escherichia coli belonging to the worldwide emerging epidemic clonal group O25b/ST131: risk factors and clinical implications

OBJECTIVES

Escherichia coli belonging to clonal group ST131 has emerged as a significant contributor to infection caused by antibiotic-resistant E. coli worldwide. We investigated the risk factors for infections caused by ST131 E. coli and their clinical implications.

METHODS

One thousand and seventy-seven E. coli isolates were screened for ST131 by molecular methods. Risk factors for ST131 were investigated separately for patients with E. coli producing and not producing extended-spectrum β-lactamases (ESBLs) in the Seville area, Spain. Multivariate analysis using logistic regression was performed. Patients with infections caused by ST131 and non-ST131 isolates were prospectively followed.

RESULTS

Independent risk factors for non-ESBL-producing ST131 were female gender (OR: 1.94; 95% CI: 1.07-3.51), diabetes mellitus (OR: 2.17; 95% CI: 1.29-3.67), bedridden status (OR: 7.75; 95% CI: 0.70-85.07) and exposure to amoxicillin/clavulanate (OR: 2.07; 95% CI: 1.08-3.96) or fluoroquinolones (OR: 2.48; 95% CI: 1.41-4.34). For ESBL-producing ST131, male gender was an independent risk factor (OR: 2.20; 95% CI: 0.94-5.11), while healthcare-related acquisition and exposure to any previous antibiotic were protective (OR: 0.30; 95% CI: 0.13-0.71; and OR: 0.43; 95% CI: 0.19-1.00, respectively). Overall, the severity of sepsis, bacteraemia and mortality were similar among ST131 and non-ST131 groups. The presence of typical factors predisposing to E. coli infection was more frequent in non-ESBL-producing ST131 than in controls (76% versus 57.2%, P = 0.005).

CONCLUSIONS

Previous use of antibiotics selecting for ST131 isolates was the main modifiable risk factor for infections caused by these isolates. Our results also suggest that the clinical virulence of ST131 is not higher than that of other common E. coli causing infections.

Improving subchondral bone integrity reduces progression of cartilage damage in experimental osteoarthritis preceded by osteoporosis

PURPOSE

Impairment of subchondral bone density and quality aggravates cartilage damage in osteoarthritis (OA). Accordingly, we assessed whether improving microstructure and quality at subchondral bone by the bone-forming agent parathyroid hormone (PTH) [1-34] prevent cartilage damage progression in a rabbit model of OA preceded by osteoporosis (OP).

METHODS

OP was induced in 20 female rabbits. At week 7, these rabbits underwent knee surgery to induce OA and, at week 12, they started either saline vehicle (n=10) or PTH (n=10) for 10 weeks. Ten healthy animals were used as controls. At week 22, microstructure was assessed by micro-computed tomography and bone remodelling by protein expression of alkaline phosphatase (ALP), metalloproteinase-9 (MMP9), osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) at subchondral bone. Cartilage damage was evaluated using Mankin score.

RESULTS

PTH reversed the decrease of bone area/tissue area, trabecular thickness, plate thickness, polar moment of inertia, ALP expression and OPG/RANKL ratio, as well as counteracted the increase of fractal dimension and MMP9 expression at subchondral bone of osteoarthritis preceded by osteoporosis (OPOA) rabbits compared to vehicle administration (P<0.05). Likewise, PTH decreased cartilage damage severity in OPOA rabbits. Good correlations were observed between subchondral bone structure or remodelling parameters, and cartilage Mankin score.

CONCLUSIONS

Improvement of microstructural and remodelling parameters at subchondral bone by PTH [1-34] contributed to prevent cartilage damage progression in rabbits with early OPOA. These findings support the role of subchondral bone in OA. Further studies are warranted to establish the place of bone-forming agents as potential treatment in OA.

PTH increases jaw mineral density in a rabbit model of osteoporosis

Intermittent parathyroid hormone (PTH) administration has been shown to be a promising therapy for systemic bone loss. Accordingly, we hypothesized that PTH could have positive results in treating oral complications of osteoporosis. Hence, we evaluated both mandibular bone loss and its response to PTH in a rabbit model of osteoporosis induced by ovariectomy and glucocorticoid administration. There was a significant and marked decrease in bone mineral density (BMD), bone mineral content (BMC), and calcium content in ash from the osteoporotic peri-alveolar region, which influenced global jaw loss. Remarkably, PTH (1-34) administration to osteoporotic rabbits almost completely reversed BMD, BMC, and calcium content fall in the peri-alveolar region, subsequently reducing global mandibular bone loss. Thus, although the peri-alveolar region is particularly susceptible to osteoporosis, it also responds well to intermittent PTH. Therefore, these results suggest that PTH might represent a valid therapy for improving the osseointegration of dental implants in persons with osteoporosis.

Clinical utility of bone marrow flow cytometry in B-cell non-Hodgkin lymphomas (B-NHL)

AIM

To determine the efficacy of flow cytometry (FC) in the assessment of bone marrow (BM) in B-cell non-Hodgkin lymphoma (B-NHL). FC is a common practice, but is far from being validated.

METHODS AND RESULTS

Morphological analysis and FC immunophenotyping were performed on 421 samples. T-cell lymphomas, Hodgkin's disease, chronic lymphocytic leukaemia and hairy cell leukaemia were not included in the study. Clonality was assessed by the standard kappa/lambda/CD19 test. Aberrant immunophenotypes present in the B-cell subpopulation were also investigated. A double-step procedure was employed in all cases to increase the sensitivity of the FC procedure. Of 380 evaluable samples, 188 corresponded to follicular lymphoma (FL), 58 to diffuse large B-cell lymphoma (DLBCL), 57 to mantle cell lymphoma (MCL), seven to Burkitt's lymphoma and the remaining 70 samples to other low-grade lymphomas. Morphological marrow infiltration was found in 148 cases, and flow immunophenotyping identified 138 cases with BM involvement. A concordance between the two methods was detected in 298 cases (79%). There was a discordance in 82 cases (21%): morphology positive/FC negative in 46 cases and morphology negative/FC positive in 36 (61% of all cases with discordance were from FL). There was no difference in outcome when patients with discordances were compared with patients without discordances.

CONCLUSIONS

Most samples showed concordance between morphological and FC results. FC identified BM involvement in the absence of morphological infiltration. Morphology/FC discordance seems to have no influence on the outcome of FL patients.

Id4 is deregulated by a t(6;14)(p22;q32) chromosomal translocation in a B-cell lineage acute lymphoblastic leukemia

BACKGROUND AND OBJECTIVES

Chromosome translocations resulting in gene overexpression are commonly associated with lymphoid neoplasia. Enhancer elements of the immunoglobulin or T-cell receptor (TCR) loci are abnormally located in the vicinity of the entire coding sequences of genes which exert an influence on the normal maturation and differentiation program of lymphoid cells.

DESIGN AND METHODS

A patient who presented with a B-cell lineage acute lymphoblastic leukemia had a t(6;14)(p22;q32). Cytogenetic and molecular findings confirmed the involvement of IgH. Molecular cloning of the breakpoint revealed that this was located near the coding sequence of the Id4 gene, a helix-loop-helix (HLH) inhibitor protein. Alu-repeated sequences at the 6p22 end flanked a short stretch of 10 bases shared by the 6p22 and 14q32 ends, suggesting that a deletion or a looping-Alu mediated mispairing mechanism may lead to this chromosome translocation.

RESULTS

Northern blot and real-time polymerase chain reaction analyses showed that the Id4 mRNA was abnormally overexpressed in this case. Only the two smaller Id4 mRNA products were detected (1.6 and 1.1 kb). Immunohistochemical analysis of Id4 protein was also assayed in a series of hematologic malignancies. Marked overexpression was found in two cases of T-cell prolymphocytic leukemias and in four B-cell lineage acute lymphoblastic leukemia including one case with the t(8;14) and another case with a p53 mutation.

INTERPRETATION AND CONCLUSIONS

The Id4 gene may behave as an oncogene in some human leukemias, perhaps through its capacity to sequester specific B-cell transcription factors. A genetic recombination between Alu-repeated sequences may not be the exclusive mechanism of generating pathogenic chromosomal translocations.

Bcl-6 p53 mutations in lymphomas carrying the bcl-2/Jh rearrangement

BACKGROUND AND OBJECTIVES

The t(14;18)(q32;q21) chromosomal translocation is the hallmark of follicular lymphomas (FL). The translocation induces the overexpression of the Bcl-2 protein and prolongs the survival of clonogenic cells. Tumor cells may acquire additional molecular alterations that may be associated with histologic progression or with chemo-resistance.

DESIGN AND METHODS

We analyzed the distribution and association of bcl-6 and p53 mutations in 55 consecutive bcl-2/Jh+ lymphoma samples derived from 43 patients obtained at the time of diagnosis and, in 5 of these patients, during follow-up. A total of 29 bcl-6 point mutations were detected in seventeen patients (40%) associated with major or minor breakpoints of the bcl-2/Jh fusion gene. In seven cases a p53 mutation was detected. Three cases corresponded to FL with the minor breakpoint in the bcl-2 gene and these patients had a favorable clinical evolution, whereas the 4 patients with p53 mutations and the major breakpoint had a bad clinical outcome with morphologic transformation to high-grade lymphoma in three cases. The sequential analysis of 5 patients showed a different timing in the acquisition of mutations: one patient showed bcl-6 and p53 mutations at diagnosis, another patient showed bcl-6 mutations at diagnosis and acquired a p53 mutation later whereas the third patient had a p53 mutation before the appearance of the bcl-6 mutation.

RESULTS

We did not find significant differences in survival between patients with FL who showed exclusively bcl-6 mutations and those without bcl-6 mutations, but those patients with a high International Progostic Index score and p53 mutations showed the lowest overall survival (p = 0.002).

INTERPRETATION AND CONCLUSIONS

These findings suggest that bcl-2/Jh lymphomas show molecular heterogeneity and that bcl-6 and p53 mutations may be acquired during the evolution of such lymphomas. Bcl-6 mutations, by themselves, do not seem to be associated with a bad prognosis. Rearrangements at the minor bcl-2 locus may have a different molecular evolution.

Interstitial deletions at the long arm of chromosome 13 may be as common as monosomies in multiple myeloma. A genotypic study

BACKGROUND AND OBJECTIVES

Deletions at the long arm of chromosome 13, mostly at the q14, and monosomy of chromosome 13 are described to be common in multiple myeloma (MM). 13q- has been associated with an adverse outcome and it has been proposed as one of the most important prognostic factors for MM patients. Deletions of 13q14 are rare in monoclonal gammopathy of undetermined significance (MGUS) and are thus believed to be associated with the development of the full myeloma phenotype.

DESIGN AND METHODS

A genotyping analysis on purified neoplastic plasma cells was performed on 14 consecutive MM cases to determine the minimally deleted region at chromosome 13. Freshly obtained bone marrow was analyzed by flow cytometry in order to establish the percentage of plasma cell infiltration (CD38+BB4+CD56+/-CD19-). Neoplastic enrichment was carried out using BB4 coated immunomagnetic beads. This method allowed us to monitor the enrichment process. DNA obtained from the enriched neoplastic population and DNA from the clean fraction was amplified using combination sets of chromosomes 12 and 13. Amplimers were run on acrylamide gels, analyzed by automatic fluorescence quantification, and their size determined using the software programs Genescan and Genotyper.

RESULTS

In 11 patients electropherograms were suggestive of loss of heterozygosity (LOH) for polymorphic markers located at the long arm of chromosome 13. Four patients showed monosomy and 7 had interstitial deletions in the telomeric region. LOH was not evidenced at chromosome 12 in any sample. The minimal region with deletion was defined by the markers D13S159 (13q32.2, centromeric) and D13S1267 (13q32.3, telomeric). A gene with a potentially pathogenic role may be located in this very small region. Three patients did not show LOH at chromosome 13 by genotypic analysis; however, in one of these, proximal deletion at the long arm of chromosome 13 (13q2.1-2.2) was demonstrated by comparative genomic hybridization (CGH).

INTERPRETATION AND CONCLUSIONS

These findings suggest that interstitial deletions of the long arm of chromosome 13 may be more common than previously recognized. The methodologic approach reported in this work may simplify LOH analysis in MM patients. The potential uses of genotyping analysis in risk stratification remain to be investigated.

Clonal heterogeneity assessed by flow cytometry in B-cell lymphomas arising from germinal centers

Patients with mature follicular B-cell lymphomas develop aggressive non-Hodgkin lymphomas (NHLs) during disease progression. It is controversial whether most diffuse large B-cell lymphomas (DLBCLs) and Burkitt lymphomas (BLs) emerge as de novo lymphomas or from an original follicular lymphoma. To distinguish clonally related populations in aggressive NHL, we studied the immunophenotypic features of 18 consecutive samples from 16 patients. Three flow cytometric patterns were distinguished: (1) a homogeneous neoplastic population of large B cells with phenotypic features of follicular center cells; (2) 2 atypical populations of B cells, small monoclonal B cells, and large B cells with loss of some surface antigens; and (3) 2 clonal populations of small and large B cells sharing the same light-chain isotype. The 3 flow cytometric patterns were observed, respectively, in de novo DLBCL and BL, transformation into BL, and transformation into DLBCL. Flow cytometric data can provide valuable information about the natural history of NHL.

Interleukin-3 receptor alpha chain (CD123) is widely expressed in hematologic malignancies

BACKGROUND AND OBJECTIVES

The hematopoietic system is controlled by growth factors (cytokines) which can influence cell survival, proliferation, differentiation and functional activation. The study of cytokine receptor expression by flow cytometry could allow us to differentiate between normal and tumoral cells.

DESIGN AND METHODS

We analyzed the expression of the interleukin-3 (IL-3) receptor a chain (CD123) in 22 normal samples and in a wide panel of hematologic malignancies using flow cytometry. We found that CD123 was expressed in the myeloid progenitor subpopulation but in contrast, normal lymphoid progenitors lacked CD123. We analyzed the CD123 expression pattern in 64 patients with acute leukemia, 45 with acute myeloid leukemia (AML) and 19 with acute lymphocytic leukemia (ALL) (13 B-cell lineage ALL and 6 T-cell lineage ALL).

RESULTS

All the AML cases except two patients with M7 and all the B-cell lineage ALL patients were CD123 positive. In contrast, all the T-cell lineage ALL cases tested were CD123 negative. We also studied the CD123 expression pattern in 122 patients with a B-cell chronic lymphoproliferative disease (B-CLPD). CD123 was positive in three situations: 1) typical cases of hairy cell leukemia showed a specific, strong CD123 expression, 2) a subgroup of atypical chronic lymphocytic leukemia with a marked CD11c expression was also CD123 positive, and finally 3) transformed B-CLPD showed the phenomenon of transition from CD123 negativity to CD123 positivity simultaneuosly with morphologic changes.

INTERPRETATION AND CONCLUSIONS

In summary, our data show high expression of IL-3 receptor a chain in hematologic malignancies. Given the high frequency of CD123 reactivity in blast cells in contrast to in normal precursors, this antigen could be applied to the study of minimal residual disease in acute leukemia. CD123 is expressed with a characteristic pattern in cases of hairy cell leukemia.

Flow cytometry using the monoclonal antibody CD10-Pe/Cy5 is a useful tool to identify follicular lymphoma cells

Follicular lymphoma (FL) is a specific entity defined by characteristic histology, phenotype and molecular rearrangements. Classically, reactivity for CD19, CD10, and strong positivity for the surface light chain immunoglobulin (SIg) are considered to be phenotypic signs typically expressed in FL. In practice, this pattern is difficult to identify since most neoplastic cells analysed by flow cytometry (FC) show weak intensity for CD19-Pe/Cy5 and for SIg and negativity for CD10-FITC. We used triple antigen combinations including two monoclonal antibodies (MoAbs) against CD10 (CD10-FITC and CD10-Pe/Cy5) and a long-distance polymerase chain reaction (PCR) approach to establish the phenotypic pattern of neoplastic cells carrying t(14;18)(q32;q21). Neoplastic cells showed the following immunophenotype: stronger reactivity against CD20 than against CD19, positivity for CD22 and SIg and negativity for CD5, CD11c and CD10-FITC. Characteristically, CD10-Pe/Cy5 was expressed in all the samples with positive bcl-2/JH rearrangements. In FL, there was a high correlation between histologic diagnosis and reactivity against CD10-Pe/Cy5 (96% cases). In diffuse large cell lymphomas (DLCL), CD10-Pe/Cy5 identified positive cases with t(14;18)(q32;q21) chromosomal translocation, whereas Burkitt lymphomas showed all cases reactivity against CD10-Pe/Cy5. In conclusion, CD10-Pe/Cy5 is a useful antibody for identifying neoplastic cells carrying t(14;18)(q32;q21) in FL and DLCL. In combination with other MoAbs, anti-CD10 (HI10a, Cy-Chrome) can be used to identify a characteristic phenotypic profile of FL against other lymphoproliferative disorders.

Leukemic relapse as T-acute lymphoblastic leukemia in a patient with acute myeloid leukemia and a minor T-cell clone at diagnosis

BACKGROUND AND OBJECTIVES

Lineage classification needs to be established before starting chemotherapy in acute leukemias. In some cases, mixed populations can be found and these are differentiated by antigenic expression patterns.

DESIGN AND METHODS

We report the case of a patient with acute myelogenous leukemia whose relapse was classified as T-acute lymphoblastic leukemia (T-ALL).

RESULTS

Flow cytometry analysis at diagnosis enabled us to identify a minor T-cell subclone which progressively increased and became dominant at relapse. There were no changes at cytogenetic and molecular levels.

INTERPRETATION AND CONCLUSIONS

This case illustrates the usefulness of multiparametric flow cytometry for assessing minor leukemic populations.

Combined use of reverse transcriptase polymerase chain reaction and flow cytometry to study minimal residual disease in Philadelphia positive acute lymphoblastic leukemia

BACKGROUND AND OBJECTIVES

The Philadelphia chromosome in acute lymphoblastic leukemia (Ph+ ALL) is associated with a poor prognosis given the high frequency of chemoresistance and leukemia relapse. Minimal residual disease (MRD) detection before cytogenetic and hematologic relapse could be useful in early therapy. The most suitable methods for detecting MRD in Ph+ ALL are flow cytometry (FC) and reverse transcriptase polymerase chain reaction (RT-PCR). However, since both techniques carry the risk of false-negative results the combined use of these two techniques could overcome this problem.

DESIGN AND METHODS

We report our experience using this approach in 47 bone marrow samples obtained from 10 Ph+ ALL patients. Twenty-seven marrow aspirates were taken from patients in clinical remission (CR). The samples were considered positive for MRD by FC when two conditions were met: 1) detection of an abnormal B-cell differentiation pattern and 2) presence of more than 1x10(-3) cells coexpressing CD22/CD34/CD45 or CD66/CD34/CD10. After FC analysis, RNA was purified using standard methods.

RESULTS

FC was positive in 23/27 samples in CR (sensitivity 85%). RT-PCR was successfully performed in 23 samples in CR. RT-PCR was positive in 18/23 samples (sensitivity 78%). There were 5 samples with discordant results. FC was positive in 3 samples with a negative RT-PCR and FC was negative in 2 samples with a positive RT. All the 10 patients relapsed and only 1 is currently alive after an allogeneic stem cell transplantation (alloSCT). The median (range) time from MRD detection to relapse in patients treated with chemotherapy was 42 (39-71) days.

INTERPRETATION AND CONCLUSIONS

These data suggest that RT-PCR may be negative despite the presence of neoplastic cells identified by their immunophenotypic traits. We conclude that immunologic and molecular techniques can be used in tandem for monitoring MRD in Ph+ ALL.

CD66 expression in acute leukaemia

Antibodies against CD66 identify antigens from the carcinoembryonic antigen (CEA) family of proteins, which belong to the immunoglobulin gene superfamily. Despite being usually restricted to cells of myeloid or monocytic origin, CD66 expression has also been reported in blasts from children with B-cell lineage acute lymphocytic leukaemia (ALL). An analysis of the CD66 expression was undertaken in a series of acute leukaemia patients. Antigenic expression was analysed using triple combinations of monoclonal antibodies (mAbs) in forty-five patients. The CD66 Kat4 fluorescein isothiocyanate clone was purchased from Dako (Glostrup, Denmark). CD66 was expressed in 2 of 29 patients with AML (acute myeloblastic leukemia) (6.8%) and in 8 of 12 patients with B-cell lineage ALL (66.7%; P<0.001); in blast crisis (BC) of chronic myelocytic leukaemia (CML), CD66 was expressed in two patients with lymphoid BC but not in the two with myeloid BC. The co-expression of CD66 with other myeloid antigens was observed in all CD66+ ALL/ Ly-BC cases tested: CD 13 in six patients, CD33 in seven and CD117 in two patients. The CD66 expression is more frequent in ALL than in AML. Furthermore, we analysed minimal residual disease (MRD) in eight patients in complete remission. CD66 expression was associated with an abnormal B-cell differentiation pattern and with increases in CD34/CD19+ cells in all but one case. These findings suggest that an aberrant expression of CD66 could be used to investigate MRD in ALL. The association between CD66 reactivity and bcr-abl in adult ALL remains to be investigated.

Comparison of the classic Glucksberg criteria and the IBMTR Severity Index for grading acute graft-versus-host disease following HLA-identical sibling stem cell transplantation. International Bone Marrow Transplant Registry

Acute graft-versus-host disease (AGVHD) severity is usually graded (grades 0-IV) by the pattern of organ involvement using the classic Glucksberg-Seattle criteria (GSC). Recently, the International Bone Marrow Transplant Registry (IBMTR) developed a new Severity Index by regrouping the patterns of organ involvement into five Indexes (0-D) that appeared more predictive of transplant-related mortality (TRM) and transplant failure (TF, relapse or TRM). We studied the predictive value of both grading systems of TRM, TF and GVHD-related mortality (GTRM) in a series of 114 consecutive patients > or = 12 years old allografted from a histocompatible sibling at our institution, 100 of whom were evaluable for AGVHD. The IBMTR Severity Index showed better incremental prediction of TRM (relative risks (RR) of 1, 1.5, 1.4, 2 and 2.5 for Indexes 0, A, B, C and D), TF (RRs of 1, 1.6, 1.6, 2 and 2.3, respectively) and GTRM (RRs of 1, 2.2 and 4.8 for Indexes B, C and D) than the GSC. With the GSC different outcomes for TRM and TF were found only from grade 0 to I-II and 0 to IV or I-III to IV, but not from I-II to III. The GSC also appeared less predictive of GTRM (RRs of 1, 0.4 and 2.9 for grades II, III and IV). In our relatively small patient sample, the new IBMTR Severity Index appeared more predictive of transplant outcome than the GSC, especially between no AGVHD, early Indexes (A-B) and advanced Indexes (C-D).

Intensive salvage chemotherapy for primary refractory or first relapsed adult acute lymphoblastic leukemia: results of a prospective trial

BACKGROUND AND OBJECTIVE

Adults with primary refractory or relapsed acute lymphoblastic leukemia (ALL) have a very poor prognosis with current salvage chemotherapies. Complete remissions (CR) can be obtained with intensive regimens in 40-60% of cases, but they are short-lived. In an effort to obtain high CR rates and prolong their duration and achieve long-term survival in a substantial number of patients, we designed an intensive combination salvage regimen (RELAL-88). In this protocol, chemotherapy was to be followed by an allogeneic or autologous stem cell transplant (SCT) within three months from CR.

DESIGN AND METHODS

Forty-five patients with primary refractory (n=17) or first relapsed ALL (n=28) were treated with the RELAL-88 five-day induction regimen comprising vindesine, mitoxantrone, cyclophosphamide, intermediate-dose Ara-C, prednisolone and methotrexate. Twenty-eight patients received granulocyte colony-stimulating factor (G-CSF), 16 patients from day 6 (early G-CSF group) and 12 from day 14 of therapy (delayed G-CSF group).

RESULTS

Thirty-four patients (74%) achieved CR (95% CI 60-87), two died in aplasia due to infection and nine were non-responders. No pretreatment variable analyzed was predictive of the chance of obtaining CR. Recovery of neutrophils occurred at a median of 29 days from the start of chemotherapy without G-CSF and 20 days with G-CSF (p = 0.005), without differences between the early and late G-CSF groups. Non-hematologic side effects were usually well tolerated and consisted mainly of infections and mucositis. Twenty-three of 34 patients (68%) who achieved CR reached the planned SCT (nine autologous and 14 allogeneic). The median overall survival was 5.7 months, and the median disease-free survival for those achieving CR was 4.6 months. Of the variables analyzed for their influence on overall survival among the 34 patients who achieved CR, only the availability of an HLA-compatible sibling was associated with a prolonged survival (p = 0.03).

INTERPRETATION AND CONCLUSIONS

The RELAL-88 intensive salvage regimen produces a very high rate of CR in poor-risk adult ALL. Non-hematologic toxicities were tolerable, and most eligible patients could undergo the planned SCT. G-CSF significantly shortened the period of neutropenia by about eight days, irrespective of whether it was started early or late after chemotherapy. However, as with other currently available salvage therapies, remissions were short-lived, and more effective post-remission treatment strategies are needed. In our experience, only allogeneic SCT offered the chance of long-term survival.

Rapid and simple immunophenotypic characterization of lymphocytes using a new test

BACKGROUND AND OBJECTIVE

In this paper, we report our experience of lymphocyte phenotyping of a series of 108 consecutive samples using a simple flow cytometry test (Lymphogram). The kit consists of a combination of 5 different markers conjugated with three fluorochromes (CD8-FITC, CD19-FITC, CD56-PE, CD3-PE, CD4-PECy5) in the same tube. This allows identification of different T-cells, NK subpopulations and B lymphocytes.

DESIGN AND METHODS

The samples were divided into three groups: samples with absolute lymphocytosis (> 5 x 10(9)/L) (n = 50), samples with relative lymphocytosis (> 50%) (n = 24) and other categories for which a lymphocyte immunophenotype was required (T-cell lymphoma and estimation of blood involvement in chronic lymphoproliferative disorders (CLPD) (n = 34). When CD19+ cells exceeded the normal range or there was a suspicion of CLPD without B-cell lymphopenia, clonality was investigated by means of light chain restriction analysis.

RESULTS

In the first group, 29 samples were abnormal (10 CLPD, 3 polyclonal B-cell lymphocytosis, 13 inversions of the CD4/CD8 ratio and 3 cases with CD4 lymphocytosis) and 21 samples were regarded as normal. In the second group 7 samples showed abnormalities (2 CLPD, 3 inverted CD4/CD8 ratios and 2 with a relative increase in CD4 cells). In one sample from the third group B-cell clonality without lymphocytosis was detected whereas in 18 samples a polyclonal pattern was observed. The presence of B-cell lymphopenia precluded further clonality study in 13 samples.

INTERPRETATION AND CONCLUSIONS

Lymphogram associated with clonality analysis is a rapid, easy and cheap method of assessing lymphocyte phenotypes in the majority of clinically relevant situations.

cCD79a expression in a case of plasma cell leukemia

In the present report we analyzed the immunophenotype of the neoplastic cells in a case of primary plasma cell leukemia (PCL). We performed simultaneous analysis of bone marrow and peripheral blood samples to investigate minor phenotypic variations that could explain the tendency of a population to leave medullary compartments. No major differences were observed between the two populations. The phenotype of the malignant clone was: CD38+, CD138+, CD19-, CD56+, CD117-, CD33+, CD44 , CD49e , cCD79a+ with positive cytoplasmic stain for kappa and IgG. Our findings expands the potential uses of cCD79a to cases of PCL with atypical morphology.

Collection of peripheral blood progenitor cells for autografting with low-dose cyclophosphamide plus granulocyte colony-stimulating factor

BACKGROUND AND OBJECTIVE

The combination of high or intermediate-dose cyclophosphamide (CY) plus granulocyte colony-stimulating factor (G-CSF) is useful to mobilize hematopoietic progenitor cells to peripheral blood, but the patients require hospitalization. The aim of this study was to evaluate the efficiency of low-dose CY plus G-CSF (5 ug/kg/day s.c.) as an outpatient treatment in order to collect enough progenitor cells for hematopoietic rescue in autologous peripheral blood transplantation (APBSCT).

DESIGN AND METHODS

We analyzed twenty-eight consecutively treated patients with lymphoma or multiple myeloma. The number of CD34+ cells in blood samples was determined from day +7. Leukapheresis (LKP) began when the absolute number of CD34+ cells in peripheral blood was > 2500/mL and the apheresis product was assayed for mononuclear cells (MNC), granulocyte-macrophage colony-forming units (CFU-GM), total nucleated cells (tNC) and CD34+ cells.

RESULTS

Twenty-eight outpatients with advanced hematologic malignancies (13 non-Hodgkin lymphoma, NHL; 10 Hodgkin's disease, HD; and 5 multiple myeloma, MM), median age 44 years (range 23-65) received a single dose of CY (1.5 g/m2 i.v. day 0) followed by G-CSF (5 ug/kg/day s.c.) from day +1 to the end of LKP. Considering patients who had successful mobilization (64%), a median of 7.1 x 10(6)/kg CD34+ cells (range 3.5-11.9), 5.7 x 10(5)/kg CFU-GM (range 1.5-9.2), 4.4 x 10(8)/kg MNC (range 1.9-7.9) were collected. Treatment was well tolerated and none of these patients was hospitalized due to neutropenic fever. Only one patient received two packed red blood cells following chemotherapy. Autologous peripheral blood stem cell transplantation (APBSCT) has been performed in 18 patients (64%). The mean number of days to achieve > 0.5 x 10(9) PMN/L and > 20 x 10(9) PLT/L was 12 (10-17) and 12.6 (8-24), respectively.

INTERPRETATION AND CONCLUSIONS

Considering a pre-established threshold of 2.5 x 10(6)/kg CD34+ cells to proceed to APBSCT, the mobilization therapy was successful in 64% of the patients but was unsuccessful in 10 patients (5 NHL, 4 HD and 1 MM). Hematopoietic recovery was complete and stable in all patients. Low-dose CY plus G-CSF is efficient to collect enough PBSC for hematopoietic rescue after myeloablative therapy in patients with lymphoprolipherative disorders or multiple myeloma.

Allogeneic or autologous stem cell transplantation following salvage chemotherapy for adults with refractory or relapsed acute lymphoblastic leukemia

Over a 9-year period 37 consecutive adults with primary refractory (n = 13) or first relapse of ALL (n = 24) received an intensive salvage chemotherapy regimen with the final intention of undergoing stem cell transplantation (SCT). Twenty-nine patients who achieved complete remission (CR) were assigned to receive autologous SCT (autoSCT) or allogeneic SCT (alloSCT) based on age and availability of a histocompatible sibling. Of the 19 patients assigned to autoSCT, 10 did not reach the transplant due to early relapse (n = 9) or fungal infection (n = 1), and nine were transplanted a median of 2.5 months (1-8) from CR, eight with an immunologically purged graft. One patient died early from ARDS and eight relapsed 2-30 months post-SCT. Three of the 10 patients assigned to alloSCT relapsed early, but all 10 received the assigned transplant a median of 2.5 months (1-7) from CR. Four died from transplant-related complications 0.7-12 months post-SCT, and six are alive and disease-free 9.7-92.6 months after the procedure. In an intention-to-treat analysis, the mean overall survival from CR for those assigned to autoSCT and alloSCT are 11.3 months (0.5-34.3) and 60.1 (2.3-98.3), respectively (log-rank, P < 0.01). Only 65% of patients who reached CR and 51% of the initial 37 cases underwent the intended SCT. We conclude that few adults with refractory or relapsed ALL actually reach SCT in CR even when the protocol used is designed for this purpose. AutoSCT appears to offer little benefit in this setting, and an alloSCT from a related or unrelated donor should be rapidly pursued after achieving CR.

Concomitant chronic lymphocytic leukemia and acute myeloid leukemia with an uncommon immunophenotype

We report a case of simultaneous diagnosis of chronic lymphocytic leukemia (CLL) and acute myeloid leukemia (AML), in which the use of flow cytometry analysis allowed the demonstration of two different cell populations and the study of both immunophenotyping patterns with a large panel of monoclonal antibodies (MoAbs). CLL cells showed a typical immunophenotype with coexpression of B cell markers with CD5, CD23, CD43, and weak surface immunoglobulin light chain restriction expression, whereas the AML population had a very uncommon phenotype with expression of myeloid markers and CD56 and lack of expression of other natural killer (NK) antigens, CD34 and HLA-DR. After chemotherapeutic treatment of AML with two induction courses, the patient achieved complete remission of the AML with persistence of a CD19/CD5 positive population. After consolidation chemotherapy, this latter population was no longer detectable despite the presence of lymphoid nodules in a bone marrow biopsy. Six months after diagnosis, the patient relapsed with AML and died shortly afterwards.

Serum erythropoietin and erythroid activity in vitamin B12 deficiency

We studied erythropoiesis in 31 patients with vitamin B12 deficiency by measuring serum erythropoietin (s-Epo), serum transferrin receptor (s-TfR, taken as an index of total erythroid activity), reticulocyte count, and the reticulocyte maturation index (RMI). s-Epo and s-TfR were measured with commercial immunoassays, whereas reticulocyte count and RMI were determined by flow cytometry. s-Epo (123 +/- 196 U/L) and s-TfR (4.1 +/- 2 mg/L) levels were increased in patients with vitamin B12 deficiency. The absolute reticulocyte counts were decreased (29 +/- 18 x 10(9)/L) with a relative increase in the most immature fractions (RMI: 29.6 +/- 18%). A significant negative relationship was found between s-Epo and Hb level (r = -0.65, p < 0.0001). On the average, however, s-Epo was inappropriately low for the degree of anemia, since the observed/predicted (O/P) s-Epo ratio was 0.80 +/- 0.28 in vitamin B12 deficiency vs 1.00 +/- 0.16 in a group of patients with iron deficiency anemia. It is concluded that at least a portion of patients with vitamin B12 deficiency have serum erythropoietin levels that are inappropriately low for the degree of anemia.