αβ and γδ T cell subsets in chronic renal failure in children on dialysis treatment

BACKGROUND: Impaired immunity, particularly cell-mediated, is one of the features of chronic renal failure. This also concerns impaired T cell dependent responsiveness. METHODS: The expression of T cell surface antigens (CD3, CD25, TCRalphabeta, TCRgammadelta) was evaluated on peripheral blood (PB) mononuclear cells using two-color flow cytometry in 10 children on continuous ambulatory peritoneal dialysis (CAPD) and in 13 children on maintenance hemodialysis (HD) with polysulfone and cuprophane dialysers. RESULTS: In HD children absolute numbers of leukocytes, lymphocytes, CD3+, alphabeta, gammadelta T cells and a percentage of gammadelta T cells were decreased versus healthy children. Also, we observed a relative increase of CD3+, CD3+/CD25+ and alphabeta T cells after sessions with cuprophane membranes, and an increase of CD3+/CD25+, alphabeta T cell percentages after sessions with the polysulfone membranes. Additionally we found a decrease of both relative and absolute numbers of gammadelta T cells after HD with polysulfone. In CAPD children we found declined absolute numbers of total lymphocytes, CD3+ and alphabeta T cells and higher relative values of CD3+ and alphabeta T cells versus controls. CONCLUSIONS: The T cell depletion in chronic renal failure (CRF) patients primarily results from uremic-related toxicities, rather than from CAPD or HD-related incompatibilities. We showed a significant decrease of gammadelta T cells in CRF patients on HD, that may be partly responsible for impaired T-dependent responsiveness in that group. The intradialytic changes of gammadelta Tcells may result from a different degree of biocompatibility during the application of various dialysis membranes.     

IL-6 and IL-10 promoter gene polymorphisms do not associate with the susceptibility for multiple myeloma

Multiple myeloma (MM) is a plasma cell malignancy characterised by bone marrow infiltration and the presence of a monoclonal protein in serum and/or urine. Interleukin-6 (IL-6) has been identified as one of the most important cytokines that contributes to myeloma cell survival and proliferation. Recent investigations suggest involvement of another cytokine, IL-10, in the activation of MM cells. The present study aimed to determine whether there is an association between the polymorphic features located within the promoter regions of IL-6 and IL-10 genes and progression the disease. IL-6 (-174 G/C) and IL-10 (-1082 A/G, -819 C/T, -592 A/C) promoter single nucleotide polymorphisms (SNPs) were determined by PCR-SSP technique using commercial primers. Our single centre results were compared with the data from literature and combined in cumulative analysis employing the Mantel-Haenszel method. In univariate analysis, only IL-10 ACC genotype tended to prevail in our (Polish) group of patients. None of IL-6 genotypes or IL-10 (-1082) alleles was found to associate with MM disease either in our single centre or in cumulative study. Among patients who died within 36 months of diagnosis, a significant prevalence (P < 0.05) of IL-6 heterozygous cases as opposed to IL-6 homozygotes was observed. IL-6 and IL-10 promoter gene polymorphisms were not found to associate with the susceptibility to the development of MM. However, the IL-6 polymorphic features appeared as factors that might affect the survival of MM patients. The latter observation warrants further study.     

Intracellular production of IL-2, IL-4 and IFN-γ by peripheral blood CD3+ cells in intermittent allergic rhinitis

Background: Allergic inflammation is mainly driven by type 2 T helper cells. The aim was to assess the changes in production of type 1 and 2 cytokines by CD3⁺ T cells dependent on natural exposure to allergens in subjects with intermittent allergic rhinitis (IAR) and in non-atopic subjects.Material: A total of 13 patients with IAR and 13 healthy non-atopics were recruited into the study. 11 patients with IAR were examined during the grass pollen season and 11 patients outside the season, 9 of them were assessed on both occasions.Methods: A flow cytometric assessment of intracellular expression of IL-2, IL-4 and IFN- by CD3⁺ cells was performed. For statistical analysis non-parametric tests were used.Results: A tendency to decreased production of IL-4 outside the season was observed (6.94% [3.42–13.33] in season vs. 2.06% [0.7–3.6] out of season). The production of IL-4 was higher in the rhinitic group in the season than in the control group (1.93% [1.07–4.97], p = 0.0034) and production of IL-2 was higher both in and outside the season (9.1% [3.94–15.09] and 10.0% [4.79–25.35] vs. 3.64% (2.64–5.03), p = 0.037 and 0.045, respectively). IL-4/IL-2 and IL-4/IFN- ratios were higher in the IAR group in the season than outside the season.Conclusion: A tendency towards a switch from a predominant type 2 response during natural allergen exposure to its suppression outside the season was found, together with a stable type 1 response.Received 22 July 2004; returned for revision 27 August 2004; accepted by M. J. Parnham 2 November 2004     

The long-term effectiveness of generic adult fixed-dose combination antiretroviral therapy for HIV-infected Ugandan children

Background

Access to pediatric antiretroviral formulations is increasing in resource-limited countries, however adult FDCs are still commonly used by antiretroviral therapy (ART) programs.

Objective

To describe long-term effectiveness of using adult FDC of d4T+3TC+NVP (Triomune) in children for HIV treatment.

Methods

Clinical, immunologic, and virologic outcomes of HIV-infected ART-naïve children aged six months to 12 years, were evaluated up to 96 weeks post-ART initiation.

Results

From March 2004 to June 2006, 104 children were followed with a median age of 5.4 years, median CD4 cell percent and HIV-1 RNA were 11.0% (IQR 6.7–13.9) and 348,846copies/mL (IQR 160,941–681,313) respectively at baseline. Using Kaplan-Meir estimates, 75% of children had undetectable viral loads (<400copies/mL) at 96weeks of ART. Children with a baseline CD4 cell percent >15% were 3 times more likely to achieve viral load <400copies/mL than those with baseline CD4 cell percent <5% after adjusting for baseline age {aHR = 3.03 (1.10–8.32), p=0.03}; no difference was found among those with CD4 cell percent >5–14.9% and <5%.

Conclusion

Treatment with generic adult FDC for HIV-infected Ugandan children led to sustained clinical, immunologic and virologic response during 96 weeks of ART. Early initiation of ART is key to achieving virological success.     

Suppression of CFTR premature termination codons and rescue of CFTR protein and function by the synthetic aminoglycoside NB54

Certain aminoglycosides are capable of inducing "translational readthrough" of premature termination codons (PTCs). However, toxicity and relative lack of efficacy deter treatment with clinically available aminoglycosides for genetic diseases caused by PTCs, including cystic fibrosis (CF). Using a structure-based approach, the novel aminoglycoside NB54 was developed that exhibits reduced toxicity and enhanced suppression of PTCs in cell-based reporter assays relative to gentamicin. We examined whether NB54 administration rescued CFTR protein and function in clinically relevant CF models. In a fluorescence-based halide efflux assay, NB54 partially restored halide efflux in a CF bronchial epithelial cell line (CFTR genotype W1282X/F508del), but not in a CF epithelial cell line lacking a PTC (F508del/F508del). In polarized airway epithelial cells expressing either a CFTR-W1282X or -G542X cDNA, treatment with NB54 increased stimulated short-circuit current (I (SC)) with greater efficiency than gentamicin. NB54 and gentamicin induced comparable increases in forskolin-stimulated I (SC) in primary airway epithelial cells derived from a G542X/F508del CF donor. Systemic administration of NB54 to Cftr-/- mice expressing a human CFTR-G542X transgene restored 15-17% of the average stimulated transepithelial chloride currents observed in wild-type (Cftr+/+) mice, comparable to gentamicin. NB54 exhibited reduced cellular toxicity in vitro and was tolerated at higher concentrations than gentamicin in vivo. These results provide evidence that synthetic aminoglycosides are capable of PTC suppression in relevant human CF cells and a CF animal model and support further development of these compounds as a treatment modality for genetic diseases caused by PTCs.     

Inactivation of Exonuclease 1 in mice results in DNA mismatch repair defects,increased cancer susceptibility,and male and female sterility

Exonuclease 1 (Exo1) is a 5'-3' exonuclease that interacts with MutS and MutL homologs and has been implicated in the excision step of DNA mismatch repair. To investigate the role of Exo1 in mammalian mismatch repair and assess its importance for tumorigenesis and meiosis, we generated an Exo1 mutant mouse line. Analysis of Exo1(-/-) cells for mismatch repair activity in vitro showed that Exo1 is required for the repair of base:base and single-base insertion/deletion mismatches in both 5' and 3' nick-directed repair. The repair defect in Exo1(-/-) cells also caused elevated microsatellite instability at a mononucleotide repeat marker and a significant increase in mutation rate at the Hprt locus. Exo1(-/-) animals displayed reduced survival and increased susceptibility to the development of lymphomas. In addition, Exo1(-/-) male and female mice were sterile because of a meiotic defect. Meiosis in Exo1(-/-) animals proceeded through prophase I; however, the chromosomes exhibited dynamic loss of chiasmata during metaphase I, resulting in meiotic failure and apoptosis. Our results show that mammalian Exo1 functions in mutation avoidance and is essential for male and female meiosis.     

Nanostructured magnetizable materials that switch cells between life and death

Development of biochips containing living cells for biodetection, drug screening and tissue engineering applications is limited by a lack of reconfigurable material interfaces and actuators. Here we describe a new class of nanostructured magnetizable materials created with a femtosecond laser surface etching technique that function as multiplexed magnetic field gradient concentrators. When combined with magnetic microbeads coated with cell adhesion ligands, these materials form microarrays of 'virtual' adhesive islands that can support cell attachment, resist cell traction forces and maintain cell viability. A cell death (apoptosis) response can then be actuated on command by removing the applied magnetic field, thereby causing cell retraction, rounding and detachment. This simple technology may be used to create reconfigurable interfaces that allow users to selectively discard contaminated or exhausted cellular sensor elements, and to replace them with new living cellular components for continued operation in future biomedical microdevices and biodetectors.     

Analysis of procalcitonin and CRP concentrations in serum of patients with chronic spontaneous urticaria

Background

Our previous findings showed the importance of analysing the peripheral markers of acute phase response (APR) activation, C-reactive protein (CRP) and IL-6 in the context of urticaria activity and severity. However, these biomarkers do not reliably differentiate between APR to infectious and the disease severity.

Aim

In order to investigate a possible association between the immune-inflammatory activation markers CRP and procalcitonin (PCT).

Methods

Serum PCT and CRP concentrations were measured in patients with CU of varying severity as well as in healthy subjects.

Results

Serum PCT and CRP concentrations were significantly increased in more severe CU patients when compared to healthy controls and mild CU, and within the CU population there was a significant correlation between concentrations of PCT and CRP. Serum PCT concentrations remained within normal ranges in most CU patients and were only slightly elevated in some severe CU cases.

Conclusions

PCT serum concentration may be only slightly elevated in some cases of severe CU. Upregulation of PCT synthesis accompanied by parallel changes in CRP concentration reflects a low-grade systemic inflammatory response in CU. PCT should be considered as a better marker than CRP to distinguish between APR to infection and an active non-specific urticarial inflammation.