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Treatment of Non-Segmental Vitiligo with Narrowband UVB Phototherapy (311 Nm): Clinical Efficacy and Mechanisms of Action
摘要： Objective: To estimate efficacy of narrowband UVB phototherapy (311 nm) in non-segmental vitiligo and its effect on subpopulations of T-cells and dendritic cells in vitiligo lesions. Methods: 56 patients with progressive non-segmental vitiligo underwent narrowband UVB phototherapy (311 nm). 11 patients had biopsies before and after therapy from lesional (depigmentation area), marginal, and perilesional skin for immunohistochemical studies of CD4+, CD8+, CD1a+ and CD83+ cells in epidermis and derma. Results: Median number of UVB procedures per course was 71, median total radiation dose-91.8 J/cm2, median percent of repigmentation-49%. Repigmentation of >25% of the affected area was reached in 67.9% of patients and repigmentation of 76-100% in 19.6% . VIDA index decreased from 2 to 1 post-treatment (P<0.035). In a subgroup who underwent immunohistochemical studies median number of UVB procedures per course was 88, median total dose of radiation-140.2 J/cm2, and median percent of repigmentation-50%. Significant activation of T-cellular immune reactions was found in lesions before treatment. There was a statistically significant increase in CD8+ lymphocytes and CD1a+ dendritic cells in marginal and perilesional normally pigmented skin in epidermis. There was an increase in CD4+ and CD8+ lymphocytes and CD83+ dendritic cells in all three zones in derma. Normalization of CD8+ and CD1+ cells in epidermis of the affected skin was observed post-treatment. There was only partial reduction of CD4+, CD8+ and CD1+ cells in dermis. Conclusions: Narrowband UVB phototherapy (311 nm) is an effective method of treatment of nonsegmental vitiligo. T-lymphocytes and Langerhans cells play a critical immunoregulatory role in narrowband UVB phototherapy (311 nm)-induced immune suppression. Lack of full normalization of immunological parameters in the skin after treatment indicates a need for optimization of narrowband UVB phototherapy (311 nm): conduction of longer courses including 150-200 procedures, or combinations of this treatment with immunosuppressive drugs.
关键词： Dendritic cells,Narrowband UVB phototherapy (311 nm),T-lymphocytes,Vitiligo,Immunohistochemical analysis
更新于2025-09-23 15:21:01
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Differences between Neutrophilic Granulocytes and Lymphocytes in Fixation of Quantum Dots of Different Composition
摘要： Studies by flow cytometry, scanning electron microscopy, and X-ray microanalysis have shown that fixation/internalization of quantum dots differ in lymphocytes and neutrophilic granulocytes. Punctate fixation of quantum dots to cell surface is characteristic of lymphocytes, while phagocytosis with perinuclear location of quantum dot aggregations is characteristic of neutrophils. The presence of complex functional groups on the surface of quantum dots can inhibit significantly the fixation/internalization of quantum dots by blood cells.
关键词： lymphocytes,neutrophilic granulocytes,internalization,quantum dots,phagocytosis
更新于2025-09-11 14:15:04
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Simplified Dynabeads Method Using Light Microscopy for Enumerating TCD4+ Lymphocytes in Resource-Limited Settings
摘要： Background: We demonstrated feasibility of implanting the Dynabeads method for CD4+ T lymphocyte enumeration in resource-poor settings (ANRS 1226 study). However, as this technique requires a fluorescence microscope which is not usually available in these settings, WHO has encouraged to simplify the method allowing TCD4+ lymphocyte counting under a light microscope. Methods: TCD4+ lymphocytes enumeration was assessed using Dynabeads after staining cells nuclei with non-fluorescent dyes and readings under light microscope (DLM). A total of 305 triple of values of CD4 cells counts were generated by both Dynabeads method using a light microscopy (DLM), Dynabeads method using a fluorescent microscope (DFM) and the single-platform flow cytometry technique (FCM). The accuracy of DLM was analyzed using 4 fresh blood samples showing 200, 400, 500 and 1000 cells/μl in FCM respectively. Correlations have been studied between the 3 methods. The DLM was then evaluated for its ability to correctly segregate absolute TCD4+ lymphocyte values at the thresholds of 200 cells/μl and 350 cells/μl. Findings: Cells nuclei staining with Sternheimer-Malbin, Turck1, and Giemsa allows TCD4+ lymphocytes enumeration using DLM. FCM has shown the greatest standard deviations and amplitudes. The reproducibility of DLM was better than FCM. The correlation coefficient between FCM and DFM was 0.975 and it was 0.973, 0.972 and 0.969 with DLM using Sternheimer-Malbin, Turck1 and Giemsa, respectively. The ability of DLM to correctly segregate TCD4+ lymphocyte values at the threshold of 200 cells/μl and 350 cells/μl was good. Conclusion: Reliable TCD4+ enumeration can be obtained with DLM. These results will contribute in resource-limited-settings to further reduce the cost of TCD4+ lymphocytes counting and make it more widely available in peripheral laboratories and even in central laboratories that face problems with maintenance and stock-out of reagents for flow cytometers.
关键词： Dynabeads method,Flow Cytometry,Resource-limited settings,Fluorescence microscopy,Light microscopy,TCD4+ lymphocytes enumeration
更新于2025-09-11 14:15:04