Cell-based therapies for the surgical treatment of periodontal intrabony defects: a systematic review

OBJECTIVE

The aim of the study is to investigate the efficacy of cell-based therapy in the surgical treatment of periodontal intrabony defects.

MATERIALS AND METHODS

PRISMA guidelines were followed, and the study protocol was regis-tered in PROSPERO. Electronic and hand searches were carried out on electronic databases and major international journals of periodontology. All randomized clinical trials (RCTs) comparing cell-based therapies com-bined with surgery to surgery alone for the treatment of periodontal intrabony defects were considered. Quality assessment was performed using the Cochrane Risk of Bias Tool for randomized clinical trials (RoB 2). Quantitative evaluation of data was performed by meta-analysis.

RESULTS

Five hundred twenty-eight records were initially screened and 5 RCTs fulfilling the eligibility criteria were included. Periodontal ligament stem cells, dental pulp stem cells, periosteum-derived stem cells, gingival fibroblasts and their associated stem cells were used in combination with different surgical techniques to treat intrabony periodontal defects. Meta-analysis showed a statistically signif-icant effect in favor of cell-based groups for clinical attachment level gain (p=0.004), with a difference in means of 1.7 mm (95% CI 0.5; 2.9). This was replicated for intrabony defect depth reduction (p=0.006), with a difference in means of 1.3 (95% CI 0.4; 2.3).

CONCLUSIONS

Cell-based therapies have been positively applied for the surgical treatment of intrabony periodontal defects with promising results. However, the results obtained should be interpreted with caution due to the low number of available RCTs, the study design heterogeneity, and the limited extension of the follow-up.

Efficacy of locally delivered statins as an adjunct to scaling and root planning in the treatment of periodontitis: a systematic review and meta-analysis

OBJECTIVE

The aim of this systematic review is to assess the efficacy of locally delivered statins used in adjunct to scaling and root planing (SRP), compared with SRP alone.

MATERIALS AND METHODS

An electronic and hand search was carried out up to April 2020. Only randomized controlled trials (RCTs) were included. Clinical attachment level gain (CALgain) and probing depth reduction (PDred), modified sulcular bleeding index reduction (mSBIred), and intrabony defect reduction (IBDred) were the investigated outcomes. Meta-analysis was performed, and the power of the meta-analytic findings was determined by trial sequential analysis (TSA). Studies were also sub-grouped based on the type of statin used. Statistical heterogeneity and publication bias were assessed.

RESULTS

Twenty RCTs were included (1212 patients, 1289 defects). An overall statistically significant effect size in favor of statins for CALgain and PDred was found. As opposed to atorvastatin and rosuvastatin, simvastatin did not reach statistical significance for these outcomes, as shown by the sub-group analysis.

CONCLUSIONS

Within the limits of the available studies, the local administration of statins (in particular, atorvastatin and rosuvastatin) in adjunct to SRP may result in additional significant improvement in terms of CALgain and PDred compared with SRP alone. The high heterogeneity of data and the high risk of bias found, however, impose caution. No approved preparations, moreover, exist, and further well-designed RCTs from independent research centers are needed to confirm the beneficial effects of the different statins and their mutual differences in the non-surgical periodontal treatment.

Role of probiotics in adjunct to non-surgical periodontal therapy in patients with chronic periodontitis: a systematic review and meta-analysis

The objective of this study was to establish the significance of probiotic usage, both as a preventive as well as a therapeutic strategy for the management of periodontal disease. It also substantiates the existing studies of single/combined bacterial strain for exhibiting variable ecological impact on oral bacteria. Data sources included literature searches of PubMed (MEDLINE), Scopus, Embase, CENTRAL and Web of science databases for placebo controlled randomized clinical trials of SRP with orally administered probiotics in any form as an adjunct. Data extraction was conducted and information from the included studies was tabulated according to the study designs, form of drug delivery, main outcomes, and clinical parameters. Data collected were based on the focused question outlined for the present systematic review. The reviewers cross-checked all extracted data. CAL and PD were assessed as the primary outcome to compare the effectiveness of adjunctive probiotic therapy in addition to SRP. Fourteen clinical studies were included and demonstrated efficacy in reducing periodontal probing depth (PPD) and gaining clinical attachment level (CAL), between probiotics and SRP/placebo. Adjunctive probiotic therapy in addition to SRP leads to decrease in probing depth and clinical attachment gain in chronic periodontitis patients. However, further high-quality randomized clinical trials with microbiological outcomes are required to fortify the conclusion.

The role of bone anabolic drugs in the management of periodontitis: a scoping review

The aim of this scoping review was to summarise current knowledge about the effects of bone anabolic drugs on periodontitis, in order to identify new therapeutic strategies for preventing disease progression and reducing tooth loss. A technical expert panel (TEP) was established of 11 medical specialists, including periodontists and bone specialists that followed the PRISMA-ScR model to perform the scoping review and considered for eligibility both pre-clinical and clinical studies published in the English language up to September 2020. 716 items were initially found. After duplicate removal and screening of articles for eligibility criteria, 25 articles published between 2001 and 2019 were selected. Only studies concerning teriparatide, strontium ranelate, sclerostin antibodies and DKK1 antibodies met the eligibility criteria. In particular, only for teriparatide were there both clinical studies and experimental studies available, while for other bone anabolic drugs only animal studies were found. Available evidence about the use of bone anabolic drugs in periodontology demonstrates beneficial effects of these agents on biological pathways and histological parameters involved in periodontal tissue regeneration that suggest relevant clinical implications for the management of periodontitis.

IL-1 Gene Cluster is Not Linked to Aggressive Periodontitis

The interleukin-1 (IL-1) gene family has been associated with susceptibility to periodontal diseases, including aggressive periodontitis (AgP); however, the results are still conflicting. The present study investigated the association between IL-1 genes and AgP using 70 markers spanning the 1.1-Mb region, where the IL-1 gene family maps, and exploring both the linkage disequilibrium (LD) and the haplotype structure in a case-control study including 95 patients and 121 control individuals. No association between AgP and IL1A, IL1B, and IL1RN genes was found in either single-point or haplotype analyses. Also, the LD map of the region 2q13–14 under the Malécot model for multiple markers showed no causal association between AgP and polymorphisms within the region (p = 0.207). In conclusion, our findings failed to support the existence of a causative variant for generalized AgP within the 2q13–14 region in an Italian Caucasian population.

Pluripotent stem cells isolated from human amniotic fluid and differentiation into pancreatic beta-cells

Human amniotic fluid (HAF) contains multipotent stem cells [amniotic fluid-derived stem cells (AFSC)] which can differentiate into a variety of different cell types. Recently, we demonstrated that obestatin, a peptide encoded by the ghrelin gene, exerts anti-apoptotic effects in pancreatic beta-cells and human islets and increases the expression of genes involved in beta-cells differentiation. We investigated whether: 1) AFSC would differentiate into pancreatic beta-cells and 2) obestatin would increase beta-cells differentiation from AFSC. Fluorescence-activated cell sorting analysis and immunocytochemical staining showed the presence of mesenchymal and endothelial markers in AFSC. Real-time PCR evidenced the expression of Octamer binding transcription factor 4 (OCT-4), a marker of pluripotency, during the early differentiation phase. However, the beta-cells differentiation marker duodenal homeobox factor-1 (PDX-1) could not be detected. Obestatin increased OCT-4 expression but had no effect on beta-cells differentiation. These results suggest that, at least under the experimental conditions used in this study, AFSC do not differentiate into beta-cells and obestatin has no additional effect.

Acetylsalicylic acid inhibits proliferation of human bone marrow stromal cells and matrix mineralization

Acetylsalicylic acid (ASA) and other non-steroidal anti-inflammatory drugs have been shown to potentially inhibit bone healing and bone formation in both animal and clinical studies. Due to the extensive diffusion of ASA-based long-term therapies, the implications of such a side-effect are of interest in all types of bone surgery, including bone grafting procedures and dental implant placement. In this study, we investigate the effect of ASA at therapeutic concentrations on the proliferation and osteogenic differentiation of human bone marrow stromal cells (BMSCs). Primary cultures of BMSCs were isolated and expanded. Their proliferation in response to ASA 50, 100 and 200 microg/ml was evaluated by MTT assay and 3H-thymidine incorporation. Cell cycle machinery was also investigated by FACS and analysis of inhibitors of cyclin-dependent kinases (CDKIs). ASA inhibited BMSC proliferation and DNA synthesis in a dose-dependent manner down to 60% of control (ASA 200 mcg/ml) at 72 h. Cell cycle analysis showed a decrease of BMSCs in the S and G2/M phases with a concomitant accumulation in G0/1 in ASA treated cells. The finding was associated to increased levels of some CDKIs, namely p27(Kip1) and p21(Cip1), whereas ASA did not affected p16(Ink4A) level at any of the concentrations employed. The matrix mineralization, that represents the major feature of the osteogenic commitment, was assessed by a specific staining procedure (von Kossa) and by calcium content determination. Both the methods demonstrated an extensive reduction (greater than 90 percent) of extracellular calcification at 200 microg/ml ASA. On the basis of our results, we can hypothesize that the widely reported inhibition of bone healing by ASA might be sustained both by a direct anti-proliferative effect on BMSCs and by an alteration of the extracellular calcification.

Effects of Emdogain on osteoblast gene expression

OBJECTIVE

Emdogain (EMD) is a protein extract purified from porcine enamel and has been introduced in clinical practice to obtain periodontal regeneration. EMD is composed mainly of amelogenins (90%), while the remaining 10% is composed of non-amelogenin enamel matrix proteins such as enamelins, tuftelin, amelin and ameloblastin. Enamel matrix proteins seem to be involved in root formation. EMD has been reported to promote proliferation, migration, adhesion and differentiation of cells associated with healing periodontal tissues in vivo.

DESIGN

How this protein acts on osteoblasts is poorly understood. We therefore attempted to address this question by using a microarray technique to identify genes that are differently regulated in osteoblasts exposed to enamel matrix proteins.

RESULTS

By using DNA microarrays containing 20,000 genes, we identified several upregulated and downregulated genes in the osteoblast-like cell line (MG-63) cultured with enamel matrix proteins (Emd). The differentially expressed genes cover a broad range of functional activities: (i) signaling transduction, (ii) transcription, (iii) translation, (iv) cell cycle regulation, proliferation and apoptosis, (v) immune system, (vi) vesicular transport and lysosome activity, and (vii) cytoskeleton, cell adhesion and extracellular matrix production.

CONCLUSIONS

The data reported are the first genome-wide scan of the effect of enamel matrix proteins on osteoblast-like cells. These results can contribute to our understanding of the molecular mechanisms of bone regeneration and as a model for comparing other materials with similar clinical effects.

In vitrocell-type specific biological response of human periodontally related cells to platelet-rich plasma

OBJECTIVES

Platelet-rich plasma is a blood-derived fraction containing high concentrations of platelets and growth factors. Applied in the form of a gel on surgical wounds, it is able to stimulate hard and soft tissue repair and has been proposed for use in the field of periodontal regeneration. However to date, little is known about the biological interactions between platelet-rich plasma and periodontally related cells. In this study, we investigated the effects between platelet-rich plasma and cell populations involved in periodontal regeneration, namely primary human periodontal ligament cells, gingival fibroblasts and keratinocytes.

MATERIAL AND METHODS

The proliferation of human periodontal ligament cells, gingival fibroblasts and keratinocytes by [3H]thymidine incorporation was assessed. The alkaline phosphatase activity and type I collagen levels of human periodontal ligament cells were also evaluated by a spectrophotometric assay and western blot analysis, respectively.

RESULTS

Incubation of human periodontal ligament cells with platelet-rich plasma resulted in time-dependent growth stimulation (up to fourfold of control at 72 h). Likewise, an increase in the specific activity of alkaline phosphatase (fourfold at 6 days) and collagen (twofold at 7 days) was observed. Platelet-rich plasma also enhanced human gingival fibroblasts proliferation by twofold, whereas it inhibited human keratinocytes growth by 40%, with respect to their own controls at 72 h.

CONCLUSION

Cell populations related to periodontal tissue were differently affected by platelet-rich plasma. In fact, a strong stimulation of human periodontal ligament cells proliferation, a minor increase in the growth rate of human gingival fibroblasts and a marked decrease of human keratinocytes proliferation were evident. In addition, in human periodontal ligament cells increased collagen and alkaline phosphatase activity levels were observed. These findings appear interesting in view of platelet-rich plasma utilization in periodontal regeneration.

Ex vivo expansion of bone marrow stromal cells by platelet-rich plasma: a promising strategy in maxillo-facial surgery

The aim of our study is to evaluate in vitro the response of bone marrow stromal cells (BMSCs) to platelet-rich plasma (PRP), in order to clarify the potential role of their combined use in a preclinical phase preceding BMSCs transplantation for bone repair and regeneration procedures. The incubation of BMSCs with PRP promoted a remarkable, dose- and time- dependent, growth stimulation, that was paralleled to a strong increase in the quantity of type I collagen and to a significant decrease in the activity of the early osteoblastic differentiation marker, alkaline phosphatase (AP). Once PRP was removed and osteogenic inducers were added, AP returned to levels comparable to the control, while the late phenotypic markers, osteocalcin and matrix calcification, were enhanced to higher levels than in controls. Our data demonstrate that PRP induces a remarkable ex vivo enrichment of BMSCs maintaining their differentiative potential. Thus PRP represents a valid preclinical tool for obtaining an effective, rapid and safe ex vivo expansion of BMSCs prior to their clinical utilization in bone engineering.

Continuous infusion idarubicin and oral busulfan as conditioning for patients with acute myeloid leukemia aged over 60 years undergoing autologous stem cell transplantation

There is growing interest in autologous stem cell transplantation (ASCT) for elderly patients with acute myeloid leukemia (AML). While mortality and toxicity from ASCT have been reduced, relapse rate is still high. In a prospective study, we investigated the feasibility of a new conditioning regimen consisting of high-dose idarubicin plus busulfan in AML patients aged over 60 years undergoing ASCT. A total of 14 patients (median age: 64 years) received 2 days continuous infusion of idarubicin at 20 mg/m2/day, followed by 3 days of oral busulfan (4 mg/kg/day) as conditioning. No case of transplant-related mortality occurred. The median number of days to neutrophil ( > 0.5 x 10(9)/l) and platelet ( > 20 x 10(9)/l) recovery was 11 and 12, respectively. Cardiac toxicity was absent, while 12 patients (86%) had grade 3-4 mucositis. After a median follow-up of 9 months from ASCT, nine of 14 patients are alive in continuous complete remission (CR), four have relapsed at 3, 6, 8 and 9 months, and one died in CR1 from gastric cancer. Our data demonstrate the feasibility of a conditioning regimen based on high-dose idarubicin plus busulfan in elderly AML patients. Results concerning reduction of relapse rate need confirmation in a larger series with longer follow-up.

Thrombophilic genotypes, natural anticoagulants, and plasma homocysteine in myeloproliferative disorders: relationship with splanchnic vein thrombosis and arterial disease

The contribution of pro-thrombotic factors towards the development of arterial disease (AD) and splanchnic vein thrombosis (SVT) was retrospectively evaluated in 79 patients (39M, 40F, mean age 55 +/- 16 years) with myeloproliferative disorders (MPD) (essential thrombocythemia [n = 26], primary proliferative polycythemia [n = 27], and idiopathic myelofibrosis [n = 26]). Of these, 18 had AD and 17 SVT, the remaining 44 were non-thrombotic (NT). Plasma concentrations of natural anticoagulants, plasma homocysteine (HC), IgG anticardiolipin antibodies (aCL), and thrombophilic genotypes (methylenetetrahydrofolate reductase C(677)T, factor V Leiden, prothrombin G(20210)-->A) were determined. Isolated protein C deficiency was found in 23% of patients from the SVT group, in 5% from the AD group, in 6.8% from the NT group, and in 1% of historical controls (P = 0.0001). The prevalence of thrombophilic genotypes and that of the other natural anticoagulants did not differ across the groups. The proportion of patients with elevated plasma HC was 66% in the AD group, 27% in the non-thrombotic group, 12% in the SVT group and 4.5% in the control group (P < 0.0001). Patients with AD had higher plasma HC (24.4 +/- 23 micromol/L) than NT patients (12.3 +/- 7.7 micromol/L), SVT patients (9 +/- 4.9 micromol/L), and healthy controls (7.9 +/- 3 micromol/L) (P < 0.0001). In a logistic regression model lower protein C was independently associated with SVT, whereas elevated plasma HC was independently associated with AD. Measurement of plasma HC and protein C in MPD may identify patients more likely to suffer arterial disease and splanchnic vein thrombosis and who may require plasma HC lowering in the former case.

High-dose idarubicin and busulphan as conditioning for autologous stem cell transplantation in acute myeloid leukemia: a feasibility study

INTRODUCTION

Between 30 and 50% of patients with acute myeloid leukemia still relapse after autologous stem cell transplantation. We investigated the feasibility of a new conditioning regimen consisting of high dose IDA plus oral busulphan in patients undergoing autologous transplantation.

MATERIALS AND METHODS

Patients (n = 13) were given three days continuous infusion IDA, followed by four days conventional dose oral busulphan as conditioning. Peripheral blood stem cells were used in all cases. Eleven patients were in CR1. Patients with t(8;21) and inv(16) as well as those with acute promyelocytic leukemia were excluded from the study. The median of CD34+ cells infused was 6.2 x 10(6)/l (2.6-16.1).

RESULTS

No case of transplant-related mortality occurred. The median number of days to neutrophil (>0.5 x 10(9)/l) and platelet (>20 x 10(9)/l) recovery was 10 (7-21) and 20 (9-26), respectively. Patients needed a median of 3 platelet units (1-6) and 3 blood units (0-12), respectively. Left ventricular ejection fraction remained unmodified after ASCT. Twelve out of 13 patients (92%) had variable grade of mucositis (two grade 2, five grade 3 and five grade 4). Total parenteral nutrition was needed in nine patients (69%). After a median follow-up of 14 months from ASCT, 11 patients out of 13 (85%) are alive in continuous CR; the other two patients experienced relapse at 12 and 14 months.

CONCLUSION

Our data demonstrate the feasibility of a conditioning regimen based on high-dose IDA plus Busulphan in AML. Results concerning antileukemic efficacy are promising, but need confirmation on larger series with longer follow-up.

Vincristine as treatment for recurrent episodes of thrombotic thrombocytopenic purpura

The clinical course of thrombotic thrombocytopenic purpura has dramatically improved after the introduction of plasma-based therapy, including plasma exchange and plasma infusion. However, a considerable number of patients still experience relapse after initial successful treatment. In this study, vincristine (VCR) was given as salvage treatment in 12 episodes of recurrent thrombotic thrombocytopenic purpura in seven patients, concomitantly with short-term plasma infusion. Complete remission (CR) was defined by normal platelet, hemoglobin, and serum lactic dehydrogenase (LDH) values as well as by absence of clinical signs. Of 12 patients, 12 achieved CR following therapy with VCR. The median duration of CR was 15 months (range: 2-16). Toxicity was mild consisting of paresthesias in three cases, leukopenia in one case, and autonomic neuropathy leading to paralytic ileus in one case. We conclude that VCR is remarkably effective for recurrent thrombotic thrombocytopenic purpura with acceptable toxicity.

Aggressive salvage treatment is not appropriate for the majority of elderly patients with acute myeloid leukemia relapsed from first complete remission

BACKGROUND AND OBJECTIVES

The prognosis of acute myeloid leukemia (AML) in the elderly is still poor because of different reasons, including a high incidence of relapse. The aim of this study was to investigate whether aggressive salvage chemotherapy (CHT) results in an actual survival advantage in elderly patients with relapsed AML, as well as to compare hospitalization and load of supportive treatment between patients receiving aggressive management or only palliation.

DESIGN AND METHODS

One hundred and fifty consecutive patients with relapsed AML (median age 66 years) were analyzed. At relapse, 99 (66%) were treated with CHT, and 51 had palliative management.

RESULTS

Second complete remission (CR2) was achieved in 36/99 patients (36%) receiving CHT, while no CR was observed in the other group (p<0.001). Induction death rate was 22%, while 41% were resistant to CHT. The median survival from relapse was 4 months for the whole patient population; according to management, it was 5 months and 3 months for CHT and palliation, respectively (p=0.01). As to patients given CHT, a CR1 duration of more than 12 months was the only parameter significantly related to a better clinical outcome (survival from relapse: 8 vs. 4 months, p=0.002; CR2 duration: 11 vs. 5 months, p=0.001, respectively). Finally, patients managed with palliation required less hospitalization and less supportive therapy as compared to the CHT group.

INTERPRETATION AND CONCLUSIONS

Aggressive chemotherapy results in an actual survival advantage only for a minority of elderly patients with relapsed AML, i.e. those with CR1 lasting for more than 12 months.

CD56 expression is an indicator of poor clinical outcome in patients with acute promyelocytic leukemia treated with simultaneous all-trans-retinoic acid and chemotherapy

PURPOSE

Preliminary reports suggest that leukemic cell expression of CD56, a neural cell adhesion molecule, is associated with adverse clinical outcome in either acute myeloid leukemia with t(8;21) or acute promyelocytic leukemia (APL). We investigated the prognostic relevance of CD56 in a series of patients with APL who were treated homogeneously with all-trans-retinoic acid (ATRA) and chemotherapy.

PATIENTS AND METHODS

Clinicobiologic presenting features and therapeutic results were analyzed in a series of 100 patients with genetically proven APL who were treated, according to the example of the Gruppo Italiano Malattie Ematologiche Maligne dell'Adulto multicenter trial, with ATRA plus idarubicin (AIDA) and for whom data on CD56 expression were available at diagnosis.

RESULTS

Fifteen patients (15%) showed expression of CD56 in greater than or equal to 20% blasts at diagnosis and were considered as CD56(+). No differences were found regarding age, sex, WBC and platelet counts, incidence of coagulopathy, hemoglobin and fibrinogen levels, promyelocytic leukemia/retinoic acid receptor (PML/RAR) alpha fusion type, or complete remission (CR) rate in the comparison of the CD56(+) and CD56(-) populations. Conversely, compared with patients who were CD56(-), patients with CD56(+) APL had shorter CR duration (P =.04) and overall survival (P =.002). In the multivariate analysis, CD56 positivity and initial WBC count greater than 10 x 10(9) cells/L retained statistical significance in overall survival (P =.04 and P =.02, respectively).

CONCLUSION

The expression of CD56 is significantly associated with inferior CR duration and survival in patients with APL who were treated with modern frontline treatment that included ATRA and simultaneous chemotherapy. Combined with other well-established prognostic factors such as WBC count, CD56 expression at diagnosis might be used to build prognostic scores for risk-adapted therapy in APL.

In vitro exposure of acute promyelocytic leukemia cells to arsenic trioxide (As2O3) induces the solitary expression of CD66c (NCA-50/90), a member of the CEA family

Arsenic trioxide (As2O3) is a useful drug for the treatment of acute promyelocytic leukemia (APL), acting through a complex mechanism involving the induction of apoptosis. We investigated by flow cytometry whether in vitro treatment of APL leukemic cells with As2O3 determined specific surface membrane changes. Twelve APL bone marrow aspirates were analyzed following 7 days of in vitro treatment with As2O3 (0.25, 0.5 and 2.5 microM) with regard to the expression of a series of differentiation antigens. Twelve acute myeloid leukemia (AML) samples of non-APL morphotype were analyzed as controls. Exposure of APL as well as non-APL samples to any concentration of As2O3 did not affect the expression of beta2 integrins (CD11a and CD11b), CD45 isoforms (RA, RB and R0), CD44/H-CAM, CD33 and the CEA-related antigen family members CD66ade and CD66b, thus failing to disclose any maturating effect. Of interest, in all APL samples (but not in AML) every tested dose of As2O3 determined a dramatic upregulation of CD66c display; intermediate concentration (0.5 microM) of As2O3 increased the median percentage of CD66c+ cells from 5% in control cultures (25th-75th percentile 2-12%) to 80% in drug-exposed cultures (25th-75th percentile 58-90%) (P<0.001). The induction of solitary expression of CD66c is a new finding which demonstrates As2O3 capability of generating phenotypic changes absolutely restricted to APL cells Moreover, these results provide experimental basis for considering the involvement of the newly described CD66 signalling pathway in As2O3-driven programmed cell death.

Vincristine as salvage treatment for refractory thrombotic thrombocytopenic purpura

Vincristine (1.4 mg/m(2) on day 1, followed by 1 mg on days 4 and 7) was given to eight patients with thrombotic thrombocytopenic purpura (TTP) who were refractory to plasma exchange (n=4) or plasma infusion (n=4). Seven of eight patients (87%) achieved a complete response; one was refractory to treatment and died within a few weeks. After a median follow-up of 50 months, all responding patients are alive and well. Two patients relapsed and were successfully retreated with vincristine. Toxicity was mild, consisting of two episodes of leukopenia and one of autonomic neuropathy leading to paralytic ileus in a patient aged 70 years. We conclude that vincristine is highly effective in the treatment of patients suffering from refractory TTP, with negligible toxicity.

Complete remission of refractory anemia following a single high dose of cyclophosphamide

We describe a case of stable complete remission in a patient with refractory anemia complicated by severe autoimmune hemolytic anemia, achieved with a single high dose (4 g/m2) of cyclophosphamide (cyclo). Concomitantly, an effective mobilization of CD34-positive cells was induced. Other immunosuppressive approaches including high-dose methylprednisolone, high-dose immunoglobulin, and cyclosporine had been ineffective. This finding suggests that, in selected cases, an immunologic mechanism may mediate cytopenia in myelodysplastic syndromes (MDS). In addition, it demonstrates that successful mobilization of peripheral blood stem cells can be induced with high-dose cyclo in MDS.

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.

Therapeutic options and treatment results for patients over 75 years of age with acute myeloid leukemia

BACKGROUND AND OBJECTIVE

Acute myeloid leukemia (AML) is a prevalent disease of the elderly. Given the progressive aging of the general population, the frequency of the disease will further increase, especially in very old individuals. In a cohort of 70 consecutive AML patients aged over 75 years, we investigated the clinico-hematological characteristics and treatment results.

DESIGN AND METHODS

Seventy patients aged > 75 were diagnosed at our institutions as having AML between January 1987 and December 1996. This figure represents 8% of the whole AML patient population observed during the same period. These patients were studied concerning the main clinical and hematological features at presentation, therapeutic approach and clinical outcome.

RESULTS

A myelodysplastic syndrome preceded the onset of AML in 10 patients (14%). Trilinear myelodysplasia was present in 28 patients (40%). Hypocellular leukemia was diagnosed in 12 cases (17%). An active infection was found in 12 patients (17%). Aggressive chemotherapy was given to 22 patients (31%), low-dose ARA-C (LDARA-C) to 7 patients (10%), while 41 (58%) were managed with supportive care and/or hydroxyurea (HU). Therapeutic choice was significantly influenced by performance status (p = .03), infections (p = .0001), severe co-morbid disease (p = .0001), and hypocellular AML diagnosis (p = .0001). Complete remission (CR) was obtained in 7/22 patients aggressively treated (32%), 0/7 in the LD-ARA-C group, and in one patient treated with HU. The median survival for the whole patient population was 18 weeks. There was no significant difference among the three treatment groups. However, patients achieving CR experienced significantly longer survival as did those with hypocellular leukemia.

INTERPRETATION AND CONCLUSIONS

In spite of a relevant selection at diagnosis, intensive chemotherapy is not appropriate for the majority of very old patients with AML. However, since a minority of patients takes substantial advantage from an aggressive approach, any effort should be made to preliminarily identify this subset at diagnosis.

Water buffalo (Bubalus bubalis) hemoglobins: an electrophoretic and chromatographic study

1. Hemoglobins from three phenotypes of Italian water buffalo (Bubalus bubalis), named AA, AB and BB, were selected by starch gel electrophoresis at alkaline pH and analyzed using polyacrylamide gel isoelectric focusing and subsequent analysis of titration curves to reveal differences between two types of hemoglobin identified as Hb fast and Hb slow. 2. Globins from Hb fast and Hb slow were purified by fast protein liquid chromatography (FPLC). Electrophoretic differences were found in the respective alpha-chains using polyacrylamide gel disc-electrophoresis at acid pH, polyacrylamide gel isoelectric focusing and by subsequently analyzing titration curves. 3. The results suggest that the alpha chains of Hb fast and Hb slow, called I alpha and II alpha, respectively, differ in at least two aminoacid residues. Subsequently, these amino acids were identified as lysine and cysteine.