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Chemokines and cytokines are involved in many processes, both physiological and pathological, particularly the recruitment, differentiation, activation, and proliferation of immune cells taking part in ontogenesis, inflammation, and cancer. It was assumed that chemokines and cytokines receptors are expressed in a regulated manner by human lymphocytes during ontogeny and later on, under the environmental stimulation of antigens they contribute to organogenesis, angiogenesis, and tissue remodeling, as well as modulating leukocyte effector functions. Using monoclonal antibodies classified by the Cytokine/Chemokine section of the 8th International Workshop on Human Leukocyte Differentiation Antigens, we analyzed human lymphocytes in blood samples drawn from the umbilical cord, normal adults, allergic and non-allergic asthma patients, HIV infected, and AIDS positive subjects. The main differences noted between adult and cord blood lymphocytes were related to CCR7 and CXCR4 receptors, which were more strongly expressed on cord blood lymphocytes, confirming the important role of these chemokines during development of the immune system. As with the HIV, CXCR4, and CCR5 co-receptors, we found no differences in CXCR4 expression between HIV and AIDS patients. However CCR5 was more strongly expressed in AIDS patients, which is likely to be associated with the evolution of disease. Further studies are needed to gain a better understanding of the functions of these molecules in the underlying pathogenesis of many diseases and to probe the use of the chemokine receptors as targets for therapeutic intervention.

Cytokines, which have been demonstrated in synovial fluids during various joint diseases, play an important role in mediating synovial inflammation and in regulating the immune response of many inflammatory processes. We studied synovial fluid, serum, and synovial fragments obtained from 33 patients—10 affected by serious gonarthrosis requiring a prosthetic implant, 8 with knee prosthesis aseptic loosening, and (as controls) 15 affected by degenerative meniscopathies—to evaluate the degree of inflammation and level of interleukins (IL-2, IL-4, IL-6, IL-10) and interferon γ secretion. Histological analysis revealed slightly more infiltration by inflammatory cells in the synovial tissue of patients with gonarthrosis and knee prosthesis aseptic loosening than in that of the control group, with a high prevalence of macrophages. Moreover, we observed enhanced production of the studied cytokines, especially in synovial fluid as compared to serum, indicating that in the pathological conditions examined the inflammatory events are mainly localized. Because the role of these cytokines is to modulate inflammation, better knowledge of the involvement of cells and their soluble mediators in articular damage could guide immunomodulating treatment.

The involvement of the synovium is common in phlogistic processes of various joint diseases. Apart from synoviocytes and the other cells in the synovial tissue, circulating cells recruited from peripheral blood also participate in the phlogistic process. The increased expression of adhesion molecules on both circulating and endothelial cell surface may further this recruitment. We studied 15 patients affected by serious gonarthrosis requiring a prosthetic implant (GPI) and 7 with knee prosthesis aseptic loosening (KPL) to evaluate adhesion molecule expression and phlogistic infiltration in the synovium using immunohistochemistry and microscopic analysis. As control we studied 10 subjects affected by degenerative meniscopathies undergoing a selective arthroscopic surgical meniscectomy. Analysis with Kruskal-Wallis test showed no statistical significant differences in the expression of CD54, CD11a, CD11b and CD18 in three groups examined. The model of variance analysis (Friedman test), showed that CD54 expression is greater in patients with GPI and KPL in comparison with the other molecules. Adhesion molecules and their functions are important in arthropathies not only because their evaluation can allow us to identify the degree of inflammation and to predict its evolution, but also because pharmacological control of their expression could have important therapeutic implications.

The understanding of the neurobiological processes leading to major depressive disorder (MDD) is an active field of research in the scientific community. For years, the alteration of monoamine neurotransmission, in particular serotonin (5-HT), has been considered the most significant pathophysiological mechanism of the disorder. However, biological data supporting the postulated MDD-related monoamine alterations have been inconclusive, and the use of monoaminergic antidepressants has not yielded the expected results. In the last few years, it has been demonstrated that inflammatory pathways have a significant role in the pathophysiology of MDD. According to the cytokine hypothesis, the disorder would be due to a stress-related increased production of cytokines, including interleukins, tumor necrosis factor- α and interferon- α and γ . These, in turns, would cause the activation of the indoleamine 2,3 dioxygenase (IDO), with subsequent production of tryptophan (TRP) catabolites along the IDO pathway (TRYCATs) and decreased availability of TRP and 5-HT. Besides monoamines, other molecular mechanisms, as those within the inflammatory pathways, should be taken into account in the attempt to clarify the pathophysiology of MDD and to improve its treatment.

We have examined the age-related changes in the kinetics of lymphocyte proliferative responses to phytohemagglutinin by flow cytometry and by the uptake of tritiated thymidine, uridine and leucine. The lymphocyte suspensions used in these experiments were obtained by umbilical cord blood samples of full-term normal newborns and from the peripheral blood of young (under 30-year-old) or aged (more than 70-year-old) healthy donors. The results indicate that the cord blood lymphocytes were activated by phytohemagglutinin to incorporate tritiated precursors of proteins, RNA and DNA at a more rapid rate than the lymphocytes from young or old donors in the first 3 days of in vitro culture. Flow cytometry confirmed higher percentages of activated cycling cells in umbilical cord blood after 24 h of culture. The lymphocytes from old donors incorporated significantly lower amounts of tritiated precursors of DNA and RNA than lymphocytes from young donors at the third day of culture. The uptake of tritiated leucine by lymphocytes from old donors was significantly reduced up to the sixth day of culture. On the contrary, at the eight day of culture, lymphocytes from old donors incorporated significantly higher amounts of labeled DNA, RNA and protein precursors. In agreement with these findings, flow cytometry demonstrated a trend towards higher percentages of cycling cells in the lymphocyte cultures from old donors after 6 and 8 days. These results indicate an age-related decline in the rate of lymphocyte blastogenesis after in vitro PHA stimulation and suggest that after a delayed PHA-induced activation, the lymphocytes from aged donors have a near-normal ability to proliferate.

We have examined the mononuclear cell (MC) subpopulations of 5 pregnant women: Three of them had a previous history of IUGR, whereas two were primiparae and presented IUGR at the term of gestation. IUGR was confirmed after delivery in three women. The analysis of MC subsets was performed by rosetting and immunofluorescence techniques; both heterologous antisera specific for human immunoglobulins and monoclonal antibodies specific for T cell antigens and for M1 and Ia-like antigens were used. The three patients with IUGR confirmed at birth presented numbers of circulating lymphoid cells positive for cytoplasmic IgM, IgG and IgA and with morphologic features of plasmablasts or plasma cells at least tenfold higher than in normal pregnant women at the term of gestation. Our data suggest that chronic activation of the lymphoid system occurs in pregnant women with IUGR. Maternal abnormal reactivity to fetal antigens or to undiagnosed chronic infections may be likely explanations for this phenomenon. Further studies are clearly needed to clarify the relationship between B-lymphocyte activation and pregnancy and to examine the hypothesis of an altered balance of the immunoregulatory T lymphocyte subsets in patients with IUGR.

We examined mononuclear cell subsets in cord blood of normal newborns by surface marker analysis. The percentages of T lymphocytes (E-rosetting and T3+ cells) were lower in cord blood than in peripheral blood (PB) from adults, while the percentage and absolute number of T6+ cells were higher in cord blood. As the sum of T4+ and T8+ cells exceeded the values of E-rosetting lymphocytes in cord blood, we suggest that immature lymphocytes with the phenotype of ‘common’ thymocytes (T6+, T4+, T8+) are present in cord blood of full-term newborns. Higher percentage and absolute number of B lymphocytes were detected in cord blood. More than 50% of B cells in cord blood formed rosettes with mouse erythrocytes, a surface marker of functional immaturity. Finally, cells bearing receptors for IgG-Fc fragments or C3 and expressing Ia-like and Ml antigens were uniformly increased in cord blood, suggesting higher percentages of cells of the monocytic lineage.

We examined mononuclear cell subsets in cord blood of normal newborns by surface marker analysis. The percentages of T lymphocytes (E-rosetting and T3+ cells) were lower in cord blood than in peripheral blood (PB) from adults, while the percentage and absolute number of T6+ cells were higher in cord blood. As the sum of T4+ and T8+ cells exceeded the values of E-rosetting lymphocytes in cord blood, we suggest that immature lymphocytes with the phenotype of 'common' thymocytes (T6+, T4+, T8+) are present in cord blood of full-term newborns. Higher percentage and absolute number of B lymphocytes were detected in cord blood. More than 50% of B cells in cord blood formed rosettes with mouse erythrocytes, a surface marker of functional immaturity. Finally, cells bearing receptors for IgG-Fc fragments or C3 and expressing Ia-like and M1 antigens were uniformly increased in cord blood, suggesting higher percentages of cells of the monocytic lineage.

The case of a patient with B cell chronic lymphocytic leukemia (CLL) and T-lymphocyte-rich pleural effusion secondary to carcinoma of the lung is presented. Monoclonal B cells were the main cell population in the peripheral blood and the helper/suppressor cell ratio of the residual T lymphocytes was lower than 1. On the contrary, T lymphocytes with helper phenotype were prevalent in the pleural fluid. The results indicate that local factors influence strongly the distribution of the lymphocyte subpopulations in different districts of the body and suggest that an etiopathogenesis unrelated to the B cell lymphoproliferative disease must be searched for, when a T-cell-rich pleural effusion is present.

We present a patient with multiple myeloma and double (IgA kappa + IgG kappa) paraproteinaemia in the serum. Immunofluorescence analysis of bone marrow plasma cell with fluorochrome-conjugated goat antibodies specific for mu, delta, gamma or alpha immunoglobulin heavy chain and kappa or lambda light chains revealed the presence of a plasma cell clone synthesizing simultaneously gamma, alpha and kappa chains. A minority of plasma cells synthesized gamma or alpha chains separately. Moreover, in the patient's peripheral blood, a few cells with the morphology of lymphoplasmoblasts and simultaneously positive for gamma, alpha and kappa chains were also detected. These results indicate that in this patient, the neoplastic plasma cell clone was 'frozen' at the differentiative step of the switch from IgG to IgA synthesis.

In the present paper we have analyzed the age-related changes in the distribution and numbers per cubic millimeter of the circulating lymphocyte subpopulations. Lymphocyte subsets have been examined by monoclonal antibodies specific for surface antigens (namely CD2, CD3, CD4, CD8, CD16, CD20 and CD57) and flow cytometry in lysed peripheral blood of normal neonates (1-3 days old), 1-6 month, 7-12 month, 1-2 year old babies and 3-5 year, 6-10 year old children and young people up to 17 years of age. The results confirm the lymphocytosis at birth and at later stages of life and indicate that major changes in the distribution of lymphocyte subsets occur during the first two years of life; namely we have observed sharp increase of circulating B lymphocytes and prevalence of CD4+ T lymphocytes with high CD4/CD8 ratios in babies up to two years of age, compared to the values observed in normal adults. Very few CD8+ CD57+ lymphocytes were present at birth; cells bearing this phenotype appeared later in life. Lymphocytes expressing the CD16 antigen were already present in newborns. The authors discuss the functional meanings of the age-related changes observed in the distribution and in the numbers of circulating lymphocytes. The presented data represent valuable normal ranges of lymphocyte subsets to compare with values observed in sick babies or children.

Previous reports indicate depression of cellular immunity during pregnancy. In order to get a deeper insight into the immunoregulatory subsets of mononuclear cells in pregnant women, we analyzed the percentages of T and B lymphocytes, T cell subsets and cells expressing IgG-Fc and C3 receptors, and M1- and Ia-like antigens in venous blood samples from healthy women and pregnant women at different gestational ages and after delivery. Even if a trend toward a progressive decrease of T lymphocytes and T4+ helper subset was observed throughout pregnancy, along with a slight increase in the percentages of cells bearing C3 receptors, M1, and Ia-like antigens in the second trimester of gestation, analysis of variance of our data did not demonstrate statistical significance in the observed changes. Therefore we conclude that the pregnancy-induced suppression of maternal responsiveness towards alloantigens and/or mitogens is not reflected by significant changes in the distribution of circulating mononuclear cells and immunoregulatory T-lymphocyte subsets as defined by the currently available surface marker techniques.