Vitamin D status and the immune assessment in 22q11.2 deletion syndrome.

22q11.2 deletion syndrome (22q11.2DS) is characterized by a heterogeneous phenotype, including alterations in phospho-calcium metabolism and immunodeficiency. We analyzed vitamin D status and the immune assessment, focusing on T cell subpopulations and dendritic cells (DCs) in a cohort of 17 pediatric 22q11.2DS patients and 17 age-matched healthy subjects. As antigen-presenting cells, DCs are the main target of vitamin D, promoting a tolerogenic T cell response. Patients were subdivided into three groups according to the parameters of phospho-calcium metabolism and serum levels of 25OHD: normal values, vitamin D deficiency and hypoparathyroidism. Different degrees of T cell deficiency, ranging from normal to partial T cell numbers, were observed in the cohort of patients. The group with vitamin D deficiency showed a significant reduction of naive T cells and a significant increase of central memory T cells compared to controls. In this group the number of circulating DCs was significantly reduced. DC decrease affected both myeloid and plasmacytoid DC subsets (mDCs and pDCs), with the most relevant reduction involving pDCs. A direct correlation between 25OHD levels and recent thymic emigrant (RTE) and DC number was identified. Despite the limited cohort analyzed, our results show that deficiency of the pDC subset in patients with 22q11.2DS may be included among the causative factors of the progressive increase of risk of autoimmune diseases in these patients. As most patients suffer from increased susceptibility to infections and heightened prevalence of autoimmune disorders, we suggest a potential role of vitamin D supplementation in preventing autoimmune or proinflammatory diseases in 22q11.2DS.

Antiproliferative effects of 5-fluorouracil and oxaliplatin in colon cancer cell lines: comparison of three different cytotoxicity assays.

Adjuvant therapy in colorectal cancer has evolved to become the standard of care, whereas the tumor capability of activating effective mechanisms of defence against both chemical and physical cytotoxic agents represents a serious obstacle to the successful therapy of human tumors. Therefore, the possibility to have an assay useful to measure the drug sensitivity of tumor cells has a great importance. A number of cytotoxicity assays are currently available, each of them using a specific approach to detect different aspects of cell viability, such as cell integrity, proliferation and metabolic functions. The purpose of this study is to compare, under identical experimental conditions, three common cytotoxicity assays (ATP-lite, MTT and CCK-8 assays) in the assessment of the anti-proliferative effects of 5-fluorouracil (5-FU) and oxaliplatin (OHP) on three colon cancer cell lines (WiDr, SW620 and HT-29). Regarding 5-FU, the three assays were found to be significantly correlated with a moderate or high correlation coefficient, whereas in the case of OHP we found different outcomes among the assays. Our study demonstrates that the CCK-8 is the most sensitive assay for detecting changes of cell viability, suggesting that the viability measured in cells after drug exposure depends on several parameters like the drug used, the biological characteristics of the target cell and the specific approach employed by the method to detect distinct cell growth and metabolic functions.

The combination of immunosuppressive drugs with 8-methoxypsoralen and ultraviolet a light modulates the myeloid-derived dendritic cell function.

The functional properties of myeloid dendritic cells (DCs) differ, depending on microenvironmental factors as well as on their stage of maturation. The main approaches for the selective enhancement of the tolerogenic properties of DCs include the induction of a pharmacological arrest of the DCs maturation and the genetical engineering of DCs expressing immunosuppressive molecules. Several immunosuppressive/anti-inflammatory agents have been discovered that potentially inhibit DC maturation and immunogenicity. Photopheresis (ECP) is an immunomodulatory therapy in which leucocytes are exposed to 8-methoxypsoralen (8-MOP) and ultraviolet (UV) A radiation (PUVA). The combination of ECP with immunosuppressive agents has demonstrated efficacy in the management of transplanted patients by reducing either the incidence of organ rejection or the pharmacological toxicity. In particular, we have observed in hepatitis C virus (HCV)-positive patients that the same combination has reduced the immunosuppressive burden and improved sustainability and efficacy of pre-emptive antiviral therapy after liver transplantation. Therefore, in our work we investigated the in vitro effects of PUVA, combined with immunosuppressive drugs (IDs), on both in vitro human DC generation and maturation, in order to contribute to understanding the immunological mechanisms underlying this pharmacological combination. Monocyte PUVA-treatment was performed by using an in vitro experimental protocol that we previously described. PUVA-treated or -untreated highly purified CD14+ cells were incubated with the association of the immunosuppressive drugs, used in the management of liver transplantation, at two different concentrations, in the presence of IL-4 and GM-CSF. The treatment with IDs at the highest concentration (corresponding to that used in clinical practice), alone or in association with PUVA, induced an immunosuppressive effect, by impairing both DC generation and maturation. Neither immunosuppressive drugs at the lowest concentration nor their combination with PUVA affected myeloid DC generation, but modified DC functions, strengthening the induction of a tolerogenic pattern. As this ID concentration was arbitrarily chosen, further experiments could highlight whether lower concentrations than those used in clinical practice would elicit the same effect on DCs and potentially improve their functional properties. This work describes an original experimental approach exploring the in vitro mechanism of action of the combined procedure of PUVA with immunosuppressive drugs, used in liver transplantation, on DCs generation and function. Our results contribute to the knowledge of the mechanisms of action of this combined procedure on DCs, suggesting useful therapeutic implications for the in vivo therapy.

Evaluation of in vitro cytotoxicity of oxaliplatin and 5-fluorouracil in human colon cancer cell lines: combination versus sequential exposure.

Adjuvant therapy has evolved to become the standard care of colon cancer, but the tumor capability of activating effective mechanisms of defence against both chemical and physical cytotoxic agents represents a serious obstacle to the successful therapy. Furthermore, the possibility to have an assay useful to measure the drug sensitivity of tumor cells could be of a great importance. As primary human colon cancer cultures from fresh tumor are technically difficult to obtain, experiments with human cancer cell lines remain essential to explore new adjuvant chemotherapy drugs, to investigate the individual responsiveness to the known agents, and particularly to clarify how these chemotherapeutic agents could be used in maximizing outcomes. In the present study we evaluate the cytotoxic effects of 5-fluorouracil (5-FU) and oxaliplatin (OHP) and of their pharmacological interaction in three human colon cancer cell lines (WiDr, HT-29 and SW620), by using an ATP luminescence assay (ATPlite; Perkin Elmer), displaying high sensitivity, linearity and reproducibility. Cell cycle, apoptosis and CD44 expression were investigated with flow cytometry. Our results show that the drug combinations inhibited the cell growth more than each drug alone in all colorectal cancer cell lines. Interestingly, the sequential exposure of OHP and 5-FU resulted in the most cytotoxic effect in all colon cancer cell lines, when compared to the simultaneous one. Our results focus on the powerful cytotoxic effect of 5-FU-OHP combination, when used in sequential exposure, suggesting interesting implications for a rational use of 5-FU, OHP combination in colon-rectal cancer therapy.

Efficacy and tolerability of mycophenolate mofetil in a pediatric Rasmussen syndrome.

Rasmussen syndrome (RS) is a chronic encephalopathy with uncertain etiology and immune-mediated pathogenesis. The only definitive treatment is represented by functional hemispherectomy. We describe the case of a 6.5-year-old female patient who developed several episodes of focal, unilateral clonic seizures. Following laboratory and instrumental investigations, the patient was diagnosed as having RS. A treatment with corticosteroids, intravenous immunoglobulin, and the antiseizure medication (carbamazepine and levetiracetam) did not completely control the seizures. Therefore, the patient was treated with mycophenolate mofetil (MMF), showing a good clinical response, with reduction of the seizures, and stability of the radiological findings. This case suggests the potential utility of MMF in the immune approach to RS.

Rasmussen's encephalitis: From immune pathogenesis towards targeted-therapy.

Rasmussen encephalitis (RE) is a unilateral hemispheric encephalitis whose main clinical features include refractory focal epilepsy or epilepsia partialis continua, hemiparesis, and progressive cognitive decline. Despite the autoimmune pathogenesis of RE, the only definitive therapeutic option is currently represented by surgery. We review the clinical features, the immune pathogenesis, and the available therapeutic options for RE, with special focus on immunosuppressive agents. The research includes systematic reviews, meta-analyses, observational studies, clinical trials, cases series and reports, until 2020. The use of immunosuppressive agents in RE is supported by the evidence of an autoimmune involvement of the central nervous system in this condition. Although often insufficient to modify the disease course and to achieve symptomatic control, immune therapy can be effective in patients with slow disease progression or in patients in which surgery is not applicable. Moreover, the documentation of T-cell involvement in the pathogenesis of RE, with a specific cytokine pattern, opens a window of opportunity for the use of T-targeted therapies and biologic drugs (i.e. anti-TNFα agents) in the treatment of this disease.

A prospective study on children with initial diagnosis of transient hypogammaglobulinemia of infancy: results from the Italian Primary Immunodeficiency Network.

Transient hypogammaglobulinemia of infancy (THI) is a heterogeneous disorder characterized by reduced serum IgG levels in early infancy. A putative diagnosis is initially made after exclusion of other causes of hypogammaglobulinemia while a definitive diagnosis of THI can only be made a posteriori in patients with normalization of IgG levels. The aim of this study is to characterize clinical and immunological features of children with an initial diagnosis of THI in correlation to natural outcome, and to assess predictive laboratory parameters of clinical evolution for this disorder. We prospectively analysed clinical and immunological characteristics of 77 THI children at initial diagnosis and of 57 patients at follow-up. Memory B cell subsets and in vitro immunoglobulin production were evaluated. Seventy patients (91 percent) showed clinical symptoms. Patients suffered from infections (91 percent), allergies (47 percent) and autoimmune disease (4 percent). During follow-up 41/57 children (72 percent) normalized IgG values, mostly within 24 months of age (p less than 0.001), allowing the diagnosis of THI. The 16 children who did not normalize their IgG levels showed a higher frequency of severe infections and autoimmune disease (p less than 0.01). Moreover, they expressed a reduced frequency of IgM and switched memory B cells (p less than 0.01) and an inability to produce IgG in vitro (p less than 0.02). We conclude that most patients with an initial diagnosis of THI spontaneously recover within 24 months of age and have a benign clinical course, while a subgroup of children with undefined hypogammaglobulinemia share a clinical and immunological profile with other primary immunodeficiencies. Early recognition of children with hypogammaglobulinemia during infancy who are likely to suffer from permanent immunodeficiencies later in life would allow prompt and appropriate laboratory and clinical interventions.

Generalized epilepsy and mild intellectual disability associated with 13q34 deletion: A potential role for SOX1 and ARHGEF7.

Terminal deletions of long arm of chromosome 13 are rare and poorly characterized by cytogenetic studies, making for difficult genotype-phenotype correlations. We report two siblings presenting generalized epilepsy, intellectual disability, and genitourinary tract defects. Array CGH detected a 1.3 Mb deletion at 13q34; it contains two protein-coding genes, SOX1 and ARHGEF7, whose haploinsufficiency can contribute to the epileptic phenotype.

In vitro cytotoxicity of docetaxel in childhood acute leukemias.

PURPOSE: In seeking to identify novel effective antileukemic agents, we assessed the in vitro activity of the taxoid docetaxel (Taxotere; Rhone-Poulenc Rorer, Antony, France) in primary leukemic cells supported in culture by bone marrow-derived stromal layers. MATERIALS AND METHODS: Bone marrow samples from children with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) were cultured on allogeneic bone marrow-derived stromal layers and exposed to various concentrations of docetaxel. After 7 days of culture, the number of viable leukemic cells were counted by flow cytometry and compared with that in parallel cultures without drugs. RESULTS: In 20 samples tested (15 B-lineage ALL, one T-lineage ALL, and four AML), the median cytotoxicity was 78% after a 7-day culture in the presence of 100 ng/mL docetaxel (range, 54% to 95%). The effects were dose-dependent and extended to all five ALL samples with the t(9;22)(q34;q11) (Philadelphia chromosome) or 11q23 abnormalities, karyotypes associated with an unfavorable outcome. Studies with continuously growing cell lines demonstrated that docetaxel exerted its cytotoxic effect by inducing apoptosis, and was consistently more effective than paclitaxel (Taxol; Bristol-Myers Squibb, Wallingford, CT) (mean 50% cell kill [LC50], 6.93 v 12.86 ng/mL in six leukemic cell lines). The antileukemic activities of docetaxel and vincristine were synergistic. While the mean (+/- SD) cytotoxicity of vincristine (0.1 ng/mL) was 11.2% +/- 7.3% and that of docetaxel (10 ng/mL) was 19.3% +/- 17.5% in CEM-C7 cells after 24 hours, combining the two agents increased the cytotoxicity to 62.5% +/- 20.7% (P = .003). CONCLUSION: Docetaxel, at concentrations achievable in vivo, is cytotoxic to ALL and AML cells. These results provide a rationale for clinical trials of docetaxel in patients with acute leukemia.

Human rIL4 fails to differentiate leukemic B-cell progenitors growing upon S17 stromal cell line.

Stromal cells appear to be key regulatory elements in hematopoiesis and lymphopoiesis. Several stromal cell lines can support B lineage by creating a hematopoietic microenvironment via cell contact or regulatory humoral molecules. These activities have been efficiently mediated by an adipocytic stromal cell line 14F1.1 on infant leukemia cells expressing a hybrid pre-B myeloid phenotype. Several murine cell clones, however, are known to have different ability to support growth and/or differentiation of leukemic cells depending on the maturational stage in which malignant cells are frozen. Pre-B-cell lines and fresh leukemias were therefore cultivated on S17 stromal cell line, before and after exposure to human recombinant interleukin 4 (rIL4), a cytokine whose effects on the growth and differentiation of the B-cell compartment depend on the developmental stage of the target B cell. In the present work, leukemic cells, both in suspension and in close contact with stromal cells, maintained their original phenotype throughout the whole period of co-culture with S17, either before or after exposure to human rIL4.

Unusual onset of a case of chronic recurrent multifocal osteomyelitis.

BACKGROUND: Chronic recurrent multifocal osteomyelitis (CRMO) is a rare condition that commonly affects the clavicle and pelvis. CASE PRESENTATION: We report here a case a 12 years old girl with CRMO arising with recurrent episodes of left supraorbital headache, followed by the appearance of a periorbital dyschromia. Magnetic resonance imaging (MRI) of the skull and orbits revealed an important subacute inflammatory process. Few months after, the child presented a painful swelling of the left clavicle; the histological examination of the related biopsy allowed to establish the diagnosis of CRMO. CONCLUSION: CRMO presenting as acute headache involving neurocranium is rare; to our knowledge this is the first recognized case in the world literature. This pathological condition is frequently misdiagnosed as infection or neoplasm and needs a deep investigation for the differential diagnosis. The physical, laboratoristic and instrumental diagnostic investigations of the patient and the treatment employed are described in detail.

The c-kit receptor and its ligand stem cell factor in childhood malignant lymphoid precursors.

The c-kit receptor (CD117) and its ligand stem cell factor (SCF) play an important role in the development, differentiation, and survival of normal and malignant hematopoietic cells. The aim of this work is to review the cellular distribution of this receptor and the effect of SCF on the hematopoietic system, particularly among lymphoid lineage, either in normal or malignant cell progenitors. We examined reports and results in the field and articles or abstracts published in journals covered by MEDLINE. Additionally, we evaluated CD117 expression on fresh blast cells of 376 newly diagnosed cases of childhood acute lymphoblastic leukemia (ALL) that were referred to centers affiliated with the Italian Association for Pediatric Hematology and Oncology (AIEOP). In view of our data, approximately 11% of ALL are CD117 positive. In particular, this receptor can be expressed in 10% and 11.5% of T-lineage and B-lineage ALL, respectively. Its expression is associated with an intermediate/mature phenotype in T-lineage ALL, whereas in B-lineage ALL, the majority of the positive cases are classified as early B ALL. The effect of SCF on malignant hematopoiesis and its potential clinical uses are reviewed.

Analytical infrared spectral differences between human normal and leukaemic cells (CLL)--I.

Two series of normal and leukaemic lymphocytes were examined by infrared spectroscopy in order to try to find spectral differences connected with chemical and biological modifications. The bands at 965 and 530 cm-1 present only in the spectra of leukaemic lymphocytes, assume particular significance. The C-H stretching region furnishes useful indications about the different ratios of the methyl groups compared with the methylene ones in the two cases. The infrared bands characteristic of the leukaemic lymphocytes seem to be due to chemical modifications not involving the DNA chain.

The effect of cytokines, including IL4, IL7, stem cell factor, insulin-like growth factor on childhood acute lymphoblastic leukemia.

We have investigated the effects of some interleukins, such as interleukin (IL) 4, IL7, stem cell factor (SCF) and insulin-like growth factor (IGF-1), known to be involved in human lymphopoiesis, on proliferation, clonal growth and differentiation of cells from two acute lymphoblastic leukemia (ALL) derived pre-B cell lines, that is, Nalm 1, Nalm 6 and purified blasts from 37 childhood ALL. IL4 did not display any promoting activity, an inhibitory effect being observed in two patients. IL7 showed an heterogeneous responsiveness, not related to immunophenotype or cytogenetic features, proliferation and clonal growth being observed in a minority of ALL. In other patients no or even inhibitory effects on proliferation were observed. In one case this inhibition of DNA synthesis was accompanied by maturation of the cells, as demonstrated by the induced expression of surface immunoglobulins (slg); other IL7 treated samples failed to express slg, but showed a decreased expression of terminal deoxynucleotidyl transferase and cALL antigen, suggesting that the cells have a potential of limited maturation by IL7. SCF, known to synergize with IL7 in the most primitive stages of normal B cell development, did not enhance the IL7 response in B cell precursor ALL. Finally IGF-1 failed to induce a proliferative response and clonal growth in BCP ALL either alone or in combination with IL7.

Human T lymphocyte cell line (Mo) and its subclone (J) produce colony stimulating activity on normal and malignant T cell precursors.

Conditioned medium from a T-lymphoblastic cell line (Mo) is known to produce factors promoting CFU-GM, BFU-E and CFU-MK. In our study we investigated the potential CSA of conditioned media obtained from Mo and its subclone J on normal and malignant lymphoid progenitors of both T and B lineage. Both cell lines release factors inducing a significant increase in number and size of T-lymphoid colonies when compared to standard source of factors (PHA-LCM). On the contrary, they presented a low CSA on B cell precursors confirming the difficulties in identifying a source of growth and differentiation factors for human B cell ontogeny. This study contributes to the knowledege of biological properties of these tumor cell lines, suggesting the possibility to employ Mo- and J-derived supernatants in vitro for improving growth potential of normal and malignant T cell progenitors.

Lymphokine release during co-culture of human lympho-mononuclear cells and fresh or cultured human, porcine and bovine pancreatic islets.

In this study we evaluated whether isolated human (HI), porcine (PI) and bovine (BI) islets, either fresh (Fr) or cultured for 4 weeks (4 w) affect cytokine release from human lymphomononuclear cells (LMC) differently. We prepared LMC from peripheral blood by density gradient purification and co-cultured 1 x 10(6) LMC for 24 h with 100 hand-picked islets, either within 48 h of isolation or after culture for 4 weeks. Soluble interleukin-2 receptor (IL-2R), interferon-gamma (IFN), interleukin-4 (IL-4) and interleukin-10 (IL-10) were measured by sandwich enzyme-linked immunoadsorbent assay. Compared with controls (Ctrl, LMC without islets), Fr-HI, Fr-PI and Fr-BI caused a similar increase of IL-2R and IFN release, whereas 4 w-HI and 4 w-BI did not lead to any significant production of these two cytokines. IL-10 concentrations increased with Fr-PI and Fr-BI, but not with Fr-HI, and no major effect of the 4-week culture was seen. IL-4 levels were below the detection limit of the method used in these experiments. Thus, fresh allo- and xeno-islets caused a similar increase of the release of cytokines known to be markers of Th1 activation, whereas the release of IL-10, a marker of Th2 activation, increased with xeno-, but not with allo-islets; culturing the islets for 4 weeks decreased Th1, but not Th2 activation.

Abnormal in vitro differentiation of clonogenic B-cells in common acute lymphoblastic leukemia in complete remission. A marker for minimal residual disease?

An in vitro B-cell colony assay system was used to evaluate B-cell differentiation from peripheral blood precursors in common acute lymphoblastic leukemia (cALL) patients in remission as compared to normal controls. Significant differences in the morphologic and phenotypic features of pooled colony cells were found between the two groups. The morphology and surface markers of control-cultured cells were those of young plasmocytes. In contrast, patients' cells had predominantly a lymphoblastoid appearance and a mean of 18% (2-72%) of the cells expressed the cALL (CALLA) antigen. This marker, known to be present on normal pre-B-cells and malignant cALL cells, was not found on control colony cells. Cytogenetic studies performed in four cases showed that a fraction of the patients' colony cells had karyotypic abnormalities similar to that of the original lymphoblasts. These data suggest that the cells with immature features persisting in the colonies of cALL patients are the progeny of residual circulating cells linked to the malignant clone which cannot be detected in the fresh sample and are clonally expanded during the culture.

[The cell-mediated response after measles vaccination]. / Studio della risposta cellulo-mediata dopo vaccinazione anti-morbillosa.

Natural measles virus infection is recognized for causing prolonged abnormalities in immune responses, that contribute to the severe and complicated evolution of the disease. Immunization with live measles virus vaccine could be considered a mild form of the measles infection. Results of investigation of in vitro immune response after measles immunization with live attenuate vaccine have been conflicting. In this work we studied cellular immune parameters in children aged between 3 and 12 years. T cells, CD4+ and CD8+ subsets were analyzed by cytometry. CD3+ cells were significantly reduced compared to controls (p < 0.01) whereas CD4+/CD8+ ratio was normal. The in vitro proliferative response to polyclonal mitogen was significantly reduced (p < 0.01). This study confirms the presence of a mainly functional immunosuppression of cellular response in a cohort of children belonging to a developed area. These findings improve the understanding of the mechanism of immune response to virus measles and provide suggestions for the development of a better approach to immunization, taking account for the strain, vaccine titre, age and environmental conditions of the target population.

[Lactate dehydrogenase isoenzymes in HIV-positive children]. / Gli isoenzimi della lattico-deidrogenasi nei bambini HIV-positivi.

Considering that in the HIV infection there is a precocious deterioration of humoral immunity with rapid turn-over of cellular B clones, we have evaluated the conduct of serum lactate-dehydrogenase activity (LD, EC 1.1.1.27) and its isoenzymes in 21 children born from HIV-positive mother respect to a control group (30 subjects). Furthermore we have checked the existence of a probable correlation between those and other clinical and immunologic parameters (total lymphocytes, CD4/CD8, immunoglobulins, classification according to the Atlanta CDC). In seropositive children we saw, respect to those evolved towards P3 stage, a significantly raising of LD4 (also vs. control group) for likely pulmonary parenchyma's damage, LD3 for B immature lymphocytes' increase and a reduction of LD1 (also vs. control group) for mature clones' decrement. Furthermore in seropositive subjects there was the existence of a direct correlation between LD1 and CD4/CD8 values. As such, the evaluation of LD isoenzymes can establish an useful element in the clinical monitoring of seropositive children.