Tumor-infiltrating γδ T cells as targets of immune checkpoint blockade in melanoma

Melanoma is one of the most sensitive tumors to immune modulation, and the major challenge for melanoma patients' survival is immune checkpoint inhibitor (ICI) therapy. γδ T lymphocytes play an antitumoral role in a broad variety of tumors including melanoma and they are optimal candidates for cellular immunotherapy. Thus, a comprehensive analysis of the correlation between γδ T cells and immune checkpoint receptors in the context of melanoma was conducted, with the aim of devising an innovative combined immunotherapeutic strategy. In this study, using the GEPIA2.0 database, a significant positive correlation was observed between the expression of γδ T cell-related genes (TRGC1, TRGC2, TCRD) and immune checkpoint genes (PDCD1, HAVCR2, LAG3), highlighting the potential role of γδ T cells in the immune response within melanoma. Moreover, flow cytometry analysis unveiled a significant augmentation in the population of γδ T cells within melanoma lesions, which exhibited the expression of immune checkpoint receptors including LAG3, TIM3, and PD1. Analysis of single-cell RNA sequencing data revealed a significant enrichment and functional reprogramming of γδ T cell clusters in response to ICIs. Interestingly, the effects of ICI therapy varied between Vδ1 and Vδ2 γδ T cell subsets, with distinct changes in gene expression patterns. Last, a correlation analysis between γδ T cell abundance, immune checkpoint gene expression, and clinical outcomes in melanoma patients showed that low expression of immune checkpoint genes, including LAG3, HAVCR2, and PDCD1, was associated with improved 1-year overall survival, emphasizing the significance of these genes in predicting patient outcomes, potentially outweighing the impact of γδ T cell abundance. This study offers critical insights into the dynamic interaction between γδ T cells, immune checkpoint receptors, and melanoma, providing valuable perspectives for potential therapeutic avenues and predictive markers in this intricate interplay.

Sicilian semi- and supercentenarians: age-related Tγδ cell immunophenotype contributes to longevity trait definition

The immune system of semi- (from ≥105 to <110 years old) and supercentenarians (≥110 years old), i.e. oldest centenarians, is thought to have characteristics that allow them to reach extreme longevity in relatively healthy status. Thus, we investigated variations of the two principal subsets of Tγδ, Vδ1, and Vδ2, and their functional subsets using the markers defining Tαβ cells, i.e. CD27, CD45RA, in a cohort of 28 women and 26 men (age range 19-110 years), including 11 long-living individuals (from >90 years old to<105 years old), and eight oldest centenarians (≥105 years old), all of them were previously analysed for Tαβ and NK cell immunophenotypes on the same blood sample collected on recruitment day. Naïve Vδ1 and Vδ2 cells showed an inverse relationship with age, particularly significant for Vδ1 cells. Terminally differentiated T subsets (TEMRA) were significantly increased in Vδ1 but not in Vδ2, with higher values observed in the oldest centenarians, although a great heterogeneity was observed. Both naïve and TEMRA Vδ1 and CD8+ Tαβ cell values from our previous study correlated highly significantly, which was not the case for CD4+ and Vδ2. Our findings on γδ TEMRA suggest that these changes are not unfavourable for centenarians, including the oldest ones, supporting the hypothesis that immune ageing should be considered as a differential adaptation rather than a general immune alteration. The increase in TEMRA Vδ1 and CD8+, as well as in NK, would represent immune mechanisms by which the oldest centenarians successfully adapt to a history of insults and achieve longevity.

Sicilian semi- and supercentenarians: identification of age-related T-cell immunophenotype to define longevity trait

The immunophenotype of oldest centenarians, i.e. semi- and supercentenarians, could provide important information about their ability to adapt to factors associated with immune changes, including ageing per se and chronic Cytomegalovirus infection. We investigated, by flow cytometry, variations in percentages and absolute numbers of immune cell subsets, focusing on T cells, and pro-inflammatory parameters in a cohort of 28 women and 26 men (age range 19-110 years). We observed variability in hallmarks of immunosenescence related to age and Cytomegalovirus serological status. The eight oldest centenarians showed the lowest percentages of naïve T cells, due to their age, and the highest percentages of T-effector memory cells re-expressing CD45RA (TEMRA), according to their cytomegalovirus status, and high levels of serum pro-inflammatory parameters, although their means were lower than that of remaining 90+ donors. Some of them showed CD8 naïve and TEMRA percentages, and exhaustion/pro-inflammatory markers comparable to the younger ones. Our study supports the suggestion that immune ageing, especially of oldest centenarians, exhibits great variability that is not only attributable to a single contributor but should also be the full result of a combination of several factors. Everyone ages differently because he/she is unique in genetics and experience of life and this applies even more to the immune system; everybody has had a different immunological history. Furthermore, our findings on inflammatory markers, TEMRA and CMV seropositivity in centenarians, discussed in the light of the most recent literature, suggest that these changes might be not unfavourable for centenarians, and in particular for the oldest ones.

Sicilian Semi- and Supercentenarians: Age-related NK Cell Immunophenotype and Longevity Trait Definition

The immune system of semi- and supercentenarians (i.e., the oldest centenarians) is believed to have peculiar characteristics that enable them to reach extreme longevity in a relatively healthy state. Therefore, in previous papers, we investigated, through flow cytometry, variations in the percentages of the main subsets of Tαβ and Tγδ cells in a Sicilian cohort of 28 women and 26 men (age range 19-110 years), including 11 long-living individuals (>90 years old) and 8 oldest centenarians. These investigations suggested that some observed immunophenotypic changes may contribute to the extreme longevity of the oldest centenarians. In the present study, to further characterize the immunophenotype of the oldest centenarians, we examined the percentages of Natural Killer (NK) cells identified as CD3-CD56 + CD16+ in the previously described Sicilian cohort. We found a highly significant increase in NK cell percentages with age. When stratified by gender, this significant increase with age was maintained in both sexes, with higher significance observed in males. Our findings on NK cells, together with the previously obtained results, discussed in the context of the literature, suggest that these changes are not unfavourable for centenarians, including the oldest ones, supporting the hypothesis that immune aging should be considered as a differential adaptation rather than a general immune alteration. These adapted immune mechanisms allow the oldest centenarians to successfully adapt to a history of insults and achieve remarkable longevity.

Role of the immune system in amyotrophic lateral sclerosis. Analysis of the natural killer cells and other circulating lymphocytes in a cohort of ALS patients

AIMS

Neuroinflammation might be involved in the degeneration and progression of Amyotrophic Lateral Sclerosis (ALS). Here, we studied the role of the circulating lymphocytes in ALS, in particular the NK cells. We focused on the relationship between blood lymphocytes, ALS clinical subtype and disease severity.

SUBJECTS AND METHODS

Blood samples were collected from 92 patients with sporadic ALS, 21 patients with Primary Lateral Sclerosis (PLS) and 37 patients affected by primary progressive multiple sclerosis (PPMS) with inactive plaques. Blood was taken from ALS and controls at the time of diagnosis/referral. Circulating lymphocytes were analyzed by flow cytometry with specific antibodies. Values were expressed as absolute number (n°/µl) of viable lymphocytes subpopulations in ALS were compared with controls. Multivariable analysis was made using site of onset, gender changes in ALSFRS-R and disease progression rate (calculated as ΔFS score).

RESULTS

Age at onset was 65y (58-71) in ALS (spinal 67.4%; bulbar, 32.6%), 57y (48-78) in PLS and 56y (44-68) PPMS. Absolute blood levels of the lymphocytes in the different cohorts were within normal range. Furthermore, while levels of lymphocytes T and B were not different between disease groups, NK cells were increased in the ALS cohort (ALS = 236 [158-360] vs. Controls = 174[113-240], p < 0.001). In ALS, blood levels of NK cells were not related with the main clinical-demographic variables, including the rate of disease progression. Multivariable analysis suggested that male gender and bulbar onset were independently associated with a risk of high blood NK cells levels.

CONCLUSIONS

We show that blood NK cells are selectively increased in ALS, though their level appear unaffected in patients with an estimated rapidly progressing disease. Being of a male gender and with a bulbar onset seems to confer higher susceptibility to have increased NK lymphocytes levels at diagnosis/referral. Our experiments provides a further clear-cut evidence of the role of the NK lymphocytes as a significant player in ALS pathogenesis.

Autologous conditioned serum for chronic pain in patients with osteoarthritis: A feasibility observational study

Background

Autologous conditioned serum is a product of blood origin, with fragmented evidence of therapeutic properties in osteoarthritis chronic pain. This pilot observational prospective study aimed to evaluate the feasibility of a treatment with conditional autologous serum (ACS) in patients with severe chronic pain and grade I-III osteoarthritis and to describe its cytokine content.

Methods

We prospectively collected data on consecutive patients affected by osteoarthritis grade I to III and treated with four weekly injections of ACS at our outpatient pain service. The primary outcome was pain intensity, measured with the visual analogic scale (VAS). Additional outcomes were symptoms evaluated using joint district-specific scales. The study also evaluated concentrations of 48 cytokines and chemokines involved in the balance pro-inflammation/anti-inflammation and tissue repair in the ACS.

Results

We included 26 patients, mostly female (65.4%), with a median age of 63.5 years [IQR 58.25-73]. A median reduction of VAS of -3 cm [-5; -1.25] was observed 6 months after the first injection of ACS. The analysis showed a statistically significant difference between the values of VAS (p < .01; X2 = 69.6; df = 6, N = 26) at the different time points. No adverse events were observed or reported by patients during the entire study period.

Conclusions

Conditional autologous serum may be a feasible option for patients with chronic pain due to grade I-III osteoarthritis refractory to other treatments. These preliminary findings should be confirmed in studies with adequate design.

γδ T cells and their clinical application in colon cancer

In recent years, research has focused on colorectal cancer to implement modern treatment approaches to improve patient survival. In this new era, γδ T cells constitute a new and promising candidate to treat many types of cancer because of their potent killing activity and their ability to recognize tumor antigens independently of HLA molecules. Here, we focus on the roles that γδ T cells play in antitumor immunity, especially in colorectal cancer. Furthermore, we provide an overview of small-scale clinical trials in patients with colorectal cancer employing either in vivo activation or adoptive transfer of ex vivo expanded γδ T cells and suggest possible combinatorial approaches to treat colon cancer.

Phenotypical and Functional Alteration of γδ T Lymphocytes in COVID-19 Patients: Reversal by Statins

(1) Background: statins have been considered an attractive class of drugs in the pharmacological setting of COVID-19 due to their pleiotropic properties and their use correlates with decreased mortality in hospitalized COVID-19 patients. Furthermore, it is well known that statins, which block the mevalonate pathway, affect γδ T lymphocyte activation. As γδ T cells participate in the inflammatory process of COVID-19, we have investigated the therapeutical potential of statins as a tool to inhibit γδ T cell pro-inflammatory activities; (2) Methods: we harvested peripheral blood mononuclear cells (PBMCs) from COVID-19 patients with mild clinical manifestations, COVID-19 recovered patients, and healthy controls. We performed ex vivo flow cytometry analysis to study γδ T cell frequency, phenotype, and exhaustion status. PBMCs were treated with Atorvastatin followed by non-specific and specific stimulation, to evaluate the expression of pro-inflammatory cytokines; (3) Results: COVID-19 patients had a lower frequency of circulating Vδ2+ T lymphocytes but showed a pronounced pro-inflammatory profile, which was inhibited by in vitro treatment with statins; (4) Conclusions: the in vitro capacity of statins to inhibit Vδ2+ T lymphocytes in COVID-19 patients highlights a new potential biological function of these drugs and supports their therapeutical use in these patients.

Anti‐inflammatory properties of lemon‐derived extracellular vesicles are achieved through the inhibition of ERK / NF‐κB signalling pathways

Chronic inflammation is associated with the occurrence of several diseases. However, the side effects of anti‐inflammatory drugs prompt the identification of new therapeutic strategies. Plant‐derived extracellular vesicles (PDEVs) are gaining increasing interest in the scientific community for their biological properties. We isolated PDEVs from the juice of Citrus limon L. (LEVs) and characterized their flavonoid, limonoid and lipid contents through reversed‐phase high‐performance liquid chromatography coupled to electrospray ionization quadrupole time‐of‐flight mass spectrometry (RP‐HPLC–ESI‐Q‐TOF‐MS). To investigate whether LEVs have a protective role on the inflammatory process, murine and primary human macrophages were pre‐treated with LEVs for 24 h and then were stimulated with lipopolysaccharide (LPS). We found that pre‐treatment with LEVs decreased gene and protein expression of pro‐inflammatory cytokines, such as IL‐6, IL1‐β and TNF‐α, and reduced the nuclear translocation and phosphorylation of NF‐κB in LPS‐stimulated murine macrophages. The inhibition of NF‐κB activation was associated with the reduction in ERK1‐2 phosphorylation. Furthermore, the ability of LEVs to decrease pro‐inflammatory cytokines and increase anti‐inflammatory molecules was confirmed ex vivo in human primary T lymphocytes. In conclusion, we demonstrated that LEVs exert anti‐inflammatory effects both in vitro and ex vivo by inhibiting the ERK1‐2/NF‐κB signalling pathway.

Metabolic Changes in Tumor Microenvironment: How Could They Affect γδ T Cells Functions?

The metabolic changes that occur in tumor microenvironment (TME) can influence not only the biological activity of tumor cells, which become more aggressive and auto sustained, but also the immune response against tumor cells, either producing ineffective responses or polarizing the response toward protumor activity. γδ T cells are a subset of T cells characterized by a plasticity that confers them the ability to differentiate towards different cell subsets according to the microenvironment conditions. On this basis, we here review the more recent studies focused on altered tumor metabolism and γδ T cells, considering their already known antitumor role and the possibility of manipulating their effector functions by in vitro and in vivo approaches. γδ T cells, thanks to their unique features, are themselves a valid alternative to overcome the limits associated with the use of conventional T cells, such as major histocompatibility complex (MHC) restriction, costimulatory signal and specific tumor-associated antigen recognition. Lipids, amino acids, hypoxia, prostaglandins and other metabolic changes inside the tumor microenvironment could reduce the efficacy of this important immune population and polarize γδ T cells toward IL17 producing cells that play a pro tumoral role. A deeper knowledge of this phenomenon could be helpful to formulate new immunotherapeutic approaches that target tumor metabolisms.

Cell quality evaluation with gene expression analysis of spheroids (3D) and adherent (2D) adipose stem cells

Adipose stem cells (ASCs) represent a reliable source of stem cells with a widely demonstrated potential in regenerative medicine and tissue engineering applications. New recent insights suggest that three-dimensional (3D) models may closely mimic the native tissue properties; spheroids from adipose derived stem cells (SASCs) exhibit enhanced regenerative abilities compared with those of 2D models. Stem cell therapy success is determined by "cell-quality"; for this reason, the involvement of stress signals and cellular aging need to be further investigated. Here, we performed a comparative analysis of genes connected with stemness, aging, telomeric length and oxidative stress, in 3D and 2D primary cultures. The expression levels of stemness-related markers and anti-aging Sirtuin1 were significantly up-regulated (P < 0.001) in SASCs-3D while gene expression of aging-related p16INK4a was increased in ASCs-2D (P < 0.001). The 3D and 2D cultures also had a different gene expression profile for genes related to telomere maintenance (Shelterin complex, RNA Binding proteins and DNA repair genes) (P < 0.01 and P < 0.001) and oxidative stress (aldehyde dehydrogenase class1 and 3) (P < 0.05, P < 0.01 and P < 0.001) and presented a striking large variation in their cellular redox state. Based on our findings, we propose a "cell quality" model of SASCs, highlighting a precise molecular expression of several genes involved with stemness (SOX2, POU5F1 and NANOG), anti-aging (SIRT1), oxidative stress (ALDH3) and telomeres maintenance.

Analysis of colon-infiltrating γδ T cells in chronic inflammatory bowel disease and in colitis-associated cancer

Inflammatory bowel disease (IBD) remains a global health problem with a significant percentage of patients progressing to chronic inflammation and colitis-associated cancer (CAC). Whether or not γδ T cells contribute to initiation and maintenance of inflammation in IBD and in the development of CAC is not known. We have evaluated the frequency, phenotype, and functions of γδ T cells among tissue-infiltrating lymphocytes in healthy donors and IBD and CAC patients. Results show that Vδ1 T cells are the dominant γδ T-cell population in healthy tissue, whereas Vδ2 T significantly abound in chronic IBD. Vδ2 T cells produce more IFN-γ, TNF-α, and IL-17 than Vδ1 T cells in chronic inflamed IBD. In CAC patients no significant cytokine production was detected in tissue-resident Vδ1 T cells, but Vδ2 T cells produced remarkable amounts of IFN-γ and TNF-α; these data were confirmed by the analysis of an independent cohort of IBD transcriptomes. Moreover, transcriptomes of IBD patients revealed a clear-cut clusterization of genes related with the maintenance of the inflammatory status. In conclusion, our results demonstrating that Vδ2 T cells have a proinflammatory profile in chronic IBD are suggestive of their participation in IBD and CAC pathogenesis.

Patients treated with antitumor drugs displaying neurological deficits are characterized by a low circulating level of nerve growth factor

The aim of our study was to explore whether nerve growth factor (NGF) plays any role in the development of peripheral neuropathy induced by anticancer treatment. We measured the circulating NGF levels in 23 cancer patients before and after chemotherapy. We evaluated whether the development of peripheral neurotoxicity was associated with changes in basal NGF concentrations in patients studied with a comprehensive neurological and neurophysiological examination. The results of these studies showed that the circulating levels of NGF, which are about 20 pg/ml in plasma of controls, decrease during chemotherapy and in some cases completely disappeared after prolonged treatment with antitumor agents. The decrease in NGF levels seems to be correlated with the severity of neurotoxicity. These results clearly suggest that NGF might become a useful agent to prevent neuropathies induced by antineoplastic drugs and restore peripheral nerve dysfunction induced by these pharmacological compounds.

Nerve growth factor: a neurotrophin with activity on cells of the immune system

Numerous studies published in the last two decades provide evidence that nerve growth factor (NGF), a polypeptide originally discovered because of its neurotrophic activity, acts on a variety of cells of the immune system, including mast cells, eosinophils, and B and T lymphocytes. NGF has been shown to increase during inflammatory responses, autoimmune disorders, parasitic infections, and allergic diseases. Moreover, stress, which is characterized also by activation of a variety of immune cells, causes a significant increase in basal plasma NGF levels. Recently published studies reveal that hematopoietic progenitor cells seem to be able to produce and/or respond to NGF. We report these data and discuss the hypothesis of the possible implication of NGF on the functional activities of immune cells.

Nerve growth factor: a survey of activity on immune and hematopoietic cells

Nerve growth factor (NGF) is a well characterized molecule required for the survival and differentiation of a variety of cell types both in the peripheral and central nervous system. Numerous studies published in recent years have demonstrated that NGF affects different functional activities of mature immune and hematopoietic cells. Other studies have revealed that hematopoietic progenitor cells from bone marrow, umbilical cord blood and peripheral blood are receptive to the action of NGF and that bone marrow stromal cells produce/respond to NGF during different steps of normal hematopoiesis. Elevated levels of NGF have been found in a number of inflammatory diseases, including those of autoimmune nature and in myeloproliferative pathologies. This review presents these data and discusses the hypothesis of a possible functional role of NGF in immune and hematopoietic disorders.

P-glycoprotein expression in de novo acute myeloid leukemia

Detection of the multidrug resistance P-glycoprotein (PGP) phenotype was performed at the time of diagnosis in 223 patients with acute myeloid leukemia (AML) by flow cytometry using C219 Monoclonal Antibody (MoAb). On the other hand, JSB1 MoAb was tested in 173 of these samples. At onset, PGP was detected in 57.4% of cases with C219 and 75.9% of cases with JSB1. There was no correlation between PGP expression and sex, age, marrow blast percentage or extramedullary disease. On the contrary, strict correlations were noted either between C219 negativity and FAB M3 subtype or between C219 positivity and FAB M5 group (P = 0.003). Significant correlation was found between PGP phenotype and CD7, as 143 of 223 samples had similar patterns of staining with C219 (P < 0.0001). Finally, there was a close relationship between C219 and JSB1 positivity: all the C219+ cases were positive for JSB1 (P < 0.0001). Concerning the karyotype, most patients with monosomy or del (7) were MDR positive; on the other hand, most patients with t(8;21) or t(15;17) were MDR negative. Rh123 accumulation studies showed a significant decrease of mean fluorescence intensities both in C219 and in JSB1 positive cases in comparison with PGP negative ones (P < 0.001). A significant decrease of remission induction rates (CR) was highlighted both between C219+ and C219- and between JSB1+ and JSB1- cases (32.1% v 62.1% and 32.6% v 73.8%, respectively, with P < 0.0001). The overall survival and the remission duration (CCR) were significantly shorter both in C219+ and in JSB1+ patients with no relationship to age. Furthermore, a higher rate of early relapses was noted among MDR+ when compared with MDR- patients both for C219+ and JSB1+ cases. The combination (C219- JSB1+) identified a subset of patients with an intermediate prognosis. On multivariate analysis, C219 and JSB1 were confirmed to be independent prognostic factors for achievement of CR, overall survival and CCR. In conclusion, the assessment of MDR phenotype by flow cytometry is a crucial prognostic factor of treatment outcome in AML.

Minimally differentiated acute myeloid leukemia (AML-M0): comparison of 25 cases with other French-American-British subtypes

We compared the immunophenotypic and karyotypic features of 25 cases of minimally differentiated acute myeloid leukemia (AML-M0) with those of 247 cases comprising all AML French-American-British (FAB) classification. Myeloperoxidase (MPO) was detectable with a specific monoclonal antibody in all cases of AML-M0, whereas CD13 and CD33 were both negative in 4 of the 25 cases. Thus, anti-MPO reliably detects minimal myeloid differentiation in AML-M0. CD34 and terminal deoxynucleotidyl transferase (TdT) were more frequently expressed in AML-M0 (96% and 68% of the cases, respectively) than in the other FAB subsets (P < .001 for both). By contrast, GP-170 and CD7 were less frequently expressed in AML-M0 than in FAB classes such as M1, M4, and M5 (P = .02 and .003, respectively). A total of 80% of AML-M0 cases carried lymphoid markers (including TdT), and 48% showed a coordinate positivity for two or more of them. CD2, CD5, CD10, and CD19 were expressed in a similar fashion among the different FAB groups, whereas CD4 expression was significantly more frequent in AML-M0, AML-M4, and AML-M5 (P = .014). AML-M0 was characterized by a more frequent occurrence of complex karyotypes. In addition, approximately 20% of cases had TdT positivity, complex karyotypes, and anomalies of chromosome 5 and/or 7, a pattern not observed in the other FAB subsets. Finally, 80% of anomalies of chromosome 5 and/or 7 in AML-M0 were comprised within complex karyotypes, whereas only 13% of the remaining FAB cases carried this feature. In summary, AML-M0 frequently expresses immunophenotypic and karyotypic aspects that are likely to identify a "stem cell" pattern.

Minimally differentiated acute myeloid leukemia (AML-M0): a distinct clinico-biologic entity with poor prognosis

FAB proposals for the diagnosis of AML-M0 represent the formal recognition of a distinct entity which has been described over the past few years by several authors and called minimally differentiated acute myeloid leukemia. By definition, AML-M0 includes acute leukemias which do not fit morphological and cytochemical criteria for the diagnosis of AML, and for which myeloid lineage assignment can be made by immunological assay showing positivity for MPO, CD13, and CD33 and negativity for lymphoid markers. Involvement of an early myeloid progenitor in the leukemic process is a possible theory hypothesized to explain the existence of such a form. Validity of this assumption has been based on the observation that AML-M0 frequently bears "stem cell" markers such as CD34, HLA-DR, Tdt, CD7, and promiscuous IgH/TCR gene rearrangements, which are thought to occur in uncommitted cells. Finally, AML-M0 very frequently carries cytogenetic abnormalities common to MDS or secondary AML, such as -5/5q- or -7/7q- deletions and or complex karyotype. In our experience, AML-M0 is also very often associated with the MDR phenotype, which in turn has been found strictly linked to "stem cell" features, especially in MDS. These biological aspects, altogether, translate into a very unfavorable prognosis, confirming even from a clinical point of view that AML-M0 is a distinct entity. In conclusion, "stem cell" markers, MDR phenotype, complex chromosome lesions, frequent occurrence in elderly patients, and intrinsic chemoresistance characterize AML-M0 and indicate the need for tailored treatments, possibly involving the use of MDR modulators and/or differentiating agents.

Contribution of immunophenotypic and genotypic analyses to the diagnosis of acute leukemia

Diagnostic accuracy in acute leukemia (AL) can be improved if traditional morphology and cytochemistry are supplemented with immunophenotypic and genotypic analyses. This multiparameter approach is of crucial importance for the management of patients, as it enables the identification of leukemic syndromes with distinct biological features and response to treatment. Immunophenotyping using monoclonal antibodies has been universally accepted as a useful adjunct to morphological criteria. This technique is particularly valuable in diagnosing and subclassifying acute lymphoblastic leukemia and is also essential in certain types of acute myeloid leukemia (AML), such as AML with minimal differentiation or acute megakaryoblastic leukemia. Cytogenetic findings can be quite helpful in establishing the correct diagnosis and can add information of prognostic significance. A number of specific chromosomal abnormalities have been recognized that are very closely, and sometimes uniquely, associated with morphologically and clinically distinct subsets of leukemia. An even more basic understanding of normal and malignant hematopoietic cells has begun to evolve as molecular biology begins to unravel gene misprogramming by Southern and Northern blot analysis, the polymerase chain reaction, and fluorescence in situ hybridization. With the extensive use of these techniques it has become apparent that a proportion of leukemias exhibit the biologically relevant molecular defect in the absence of a karyotypic equivalent. On the other hand, apparently uniform chromosomal abnormalities such as the t(1;19) (q23;p13), t(9;22) (q33;q11), t(8;14) (q24;q32), or t(15;17) (q21;q21) may differ at the molecular level. Data collected from these modern technologies have introduced a greater complexity, which needs to be taken into consideration to improve both the diagnostic precision and the reproducibility of current classifications.

CD7 expression in acute myeloid leukemia

The clinical significance of the expression of CD7 antigen on the blasts of 207 consecutive patients with de novo acute myeloid leukemia (AML) was evaluated. For this purpose, fifty-three CD7+ patients (23 females and 30 males; mean age 52 years) were analyzed and classified into the following subtypes according to French-American-British (FAB) classification: 7 M0, 13 M1, 9 M2, 1 M3, 9 M4, 14 M5. Immunophenotypic studies were carried out by flow cytometry and blast cells were selected on the basis of forward light scatter gating and pan-myeloid marker, either CD13 or CD33. All the CD7+ patients were negative for surface CD3 and T-cell-receptor (TCR) molecules. We found no correlation between CD7 expression and sex, age, hepatosplenomegaly and/or central nervous system involvement. The immaturity of CD7+ leukemic cells was supported by the high expression of CD34 (P = 0.001). CD7 positivity was significantly associated with a white blood cell count (WBC) greater than 100 x 10(9)/L (P = 0.003). P-Glycoprotein (P-170) expression was also evaluated in 135 patients by a flow-cytometric assay: there was a close relationship between CD7 and P-170 positivity (P < 0.001). For remission induction, all patients received therapeutic regimens routinely used for AML. The complete remission (CR) rate was significantly lower in CD7+ cases (32% vs 74%, P = 0.001). The overall survival and disease free survival rate of CD7+ AML was lower than those of CD7- patients (P < 0.001 and = 0.002, respectively). CD7+ AML with coexpression of CD14 had a particularly unfavourable response and prognosis in comparison with CD7+ patients without CD14.(ABSTRACT TRUNCATED AT 250 WORDS)

Minimally differentiated acute myeloid leukaemia (AML-M0): cytochemical, immunophenotypic and cytogenetic analysis of 19 cases

We describe our experience in the identification of 19 cases of AML-M0 categorized among 200 consecutive AML cases. Leukaemic cells from our cases were morphologically marked by agranular basophilic cytoplasm, finely dispersed chromatin and prominent nucleoli. In two cases heavily vacuolated and monocytoid-shaped blasts were also observed. Cytochemistry (MPO, SBB, alpha ANAE, alpha NBE, NASDCAE, AP, PAS) was negative in 14 cases, five cases expressing a very faint cytoplasmic positivity for alpha NBE (not exceeding 30% of the blasts) and alpha ANAE (not exceeding 41%) which was sodium fluoride resistant. In these five cases other monocytic markers (e.g. CD14) were not in favour of myelomonocytic differentiation. All the cases were anti-MPO positive at frequency > 10%. Phenotypic analysis also revealed myeloid features with all the patients having at least one myeloid antigen (CD13, CD33, CD15), Tdt was expressed in nine cases and CD7 in six cases. All cases but one were positive for CD34. Cytogenetic analysis, performed in 16 cases, showed no adequate growth in two cases and no consistent abnormality in four; among the remaining 10 cases no consistent abnormality was observed, the most common finding was trisomy 8 (two cases) and 4 (two cases) and aberrations of chromosomes 2, 3, 5, 7, 9, 12 and 21. No cases of (t9;22), Ph chromosome were observed. Interestingly three out of five patients with faint alpha NBE/alpha ANAE positivity relapsed as typical M4 (one case) or M5a (two cases).

Triple immunofluorescence evaluation of CD15, CD34 and class II expression by flow cytometry in normal and leukemic bone marrows

BACKGROUND

The CD15/CD34 phenotype has been reported as aberrant and exploited for monitoring minimal residual disease in acute myeloid leukemia (AML) patients. Moreover, CD15/CD34 has been described as a rare phenotype in normal bone marrow (NBM) (< 0.10%). We used a triple immunofluorescence assay to investigate the expression of CD15, CD34 and class II antigens in normal (NMB) and leukemic (LBM) bone marrows.

METHODS

A FACScan for quantitative fluorescence and the PAINT-A-GATE program for multiparametric analysis were utilized. Fifteen normal bone marrow and fifteen leukemic bone marrow samples were studied with a triple immunofluorescence assay. A FACSorter was used for sorting.

RESULTS

Eleven out of 15 normal marrows contained less than 0.67% (range 0.01-0.66) cells which coexpressed CD15, CD34 and class II antigens. Three normal marrows contained more than 0.67% but less than 1.84% (range 1.05-1.83) triple stained cells. The entire group of leukemic marrows coexpressed triple stained cells with a frequency higher than 1% (range 1.1-48.6); furthermore, 10 samples contained the same population at frequencies higher than 10%. The difference between normal and leukemic marrows was statistically significant (p = < 0.001). Triple positive cells (TPc) from NBM were sorted for morphology, which proved to be consistent with myeloid progenitor features (early myeloblasts). This confirms that CD15+ CD34+ Class II+ precursors are commonly expressed in NMB, although at low frequency. Interestingly, 12 (80%) AMLs out of 15 were diagnosed as M1 (5) or M2 (7), while the remaining were M4 (2) and M5a (1). Additionally, all M2 cases were positive at percentages higher than 10%. Apparently CD15, CD34, class II expression correlates mainly with granulocyte differentiation. Two complete remission (CR) LBM, positive at onset for the triple combination, were regularly monitored. In one case the TPc percentage always remained near the normal values found in NBM (0.72%), and this patient is still in CR. In the other, overt relapse was preceded by a progressive increase in the TPc percentage.

CONCLUSIONS

Although the presence in NBM of CD15+ CD34+ and class II+ precursors hinders minimal residual disease detection, we conclude that this unusual combination may distinguish a leukemic population and may allow monitoring of "early relapse".

Soluble factors levels in the initial staging of high-grade non-Hodgkin's lymphomas

Plasma levels of several soluble factors were assayed in 31 untreated patients with high-grade non-Hodgkin's lymphomas (NHL). The results showed statistically significant higher average levels of interleukin-2 (IL-2), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-2 receptor (IL-2r) and transferrin receptor (TF-r) in NHL patients compared to controls (p = 0.045, p = 0.047, p = 0.020, p = 0.026 and p = 0.033 respectively). IL-2, IL-2r and TF-r levels were found more elevated in Stages III/IV than in Stages I/II (p = 0.031, p = 0.016 and p = 0.048 respectively), whereas IL-6 concentrations were higher in patients presenting B symptoms (p = 0.011). Significant correlations were found between the erythrocyte sedimentation rate (ESR) and IL-6 (r = 0.681), and between beta 2 microglobulin (B2-m) and IL-2r (r = 0.622).