Adequate immune responses to vaccines after chemotherapy for leukaemia diagnosed in childhood.

AIM: The survival rate after treatment for childhood leukaemia has greatly improved, but could result in protracted immune deficiency. This study examined the immune status of children after chemotherapy and evaluated their responses to immunisation. METHODS: Subjects who had completed their treatment for acute lymphoblastic leukaemia at The Children's Hospital Reykjavík, Iceland, during 2011-2020 had blood drawn and were then immunised for influenza in October 2021. Blood was drawn again 4 weeks later and their humoral and cellular responses were measured with a haemagglutination inhibition assay and lymphocyte stimulation test. Antibodies to other immunisations were also evaluated. RESULTS: We studied 18 patients (10 male) who had completed their treatment at 3.7-20.3 years of age (mean 9.1), 11-84 months (mean 36.9) before enrolment. Conventional immunological evaluation did not reveal notable abnormalities. The responses to several childhood vaccinations, including the pneumococcal conjugate vaccination, were adequate in most patients. Humoral responses to the influenza vaccine confirmed adequate reactions in all but one patient. Considerable variations were observed in the lymphocyte stimulations tests. CONCLUSION: Most patients reacted adequately to immunisation, especially against annual influenza and Streptococcus pneumoniae, reiterating the usefulness of vaccinations. The most appropriate timing for vaccination after treatment still needs to be determined.

Profiling inflammatory response in lesions of cutaneous leishmaniasis patients using a non-invasive sampling method combined with a high-throughput protein detection assay.

BACKGROUND: Cutaneous leishmaniasis (CL) is an infection caused by Leishmania (L.) protozoa transmitted through the bite of infected sand fly. Previously, invasive sampling of blood and skin along with low throughput methods were used for determination of inflammatory response in CL patients. AIMS/METHODOLOGY: We established a novel approach based on a non-invasive adhesive tape-disc sampling combined with a powerful multiplexing technique called proximity extension assay for profiling 92 inflammatory cytokines, chemokines and surface molecules in the lesions of CL patients infected with L. tropica. Sample collection was done non-invasively by using adhesive tape-discs from lesion and normal skin of 33 L. tropica positive patients. RESULTS: Out of 92 inflammatory proteins, the level of 34 proteins was significantly increased in the lesions of CL patients compared to their normal skin. This includes the chemokines CCL2, CCL3, CCL4, CXCL1, CXCL5, CXCL9, CXCL10 and CXCL11, together with the interleukins IL-6, IL-8, IL-18, LIF and OSM. The remaining significantly changed inflammatory proteins include 7 surface molecules and receptors: CD5, CD40, CDCP1, 4E-BP1, TNFRSF9, IL-18R1 and OPG as well as 16 other cytokines and proteins: MMP-1, CSF-1, VEGFA, uPA, EN-RAGE, LAP TGF-ß1, HGF, MMP-10, CASP-8, TNFSF14, STAMPB, ADA, TRAIL and ST1A1. Further, 13 proteins showed an increasing trend, albeit not statistically significant, in the CL lesions, including TGF-α, CCL23, MCP-2, IL-12B, CXCL6, IL-24, FGF-19, TNFß, CD6, TRANCE, IL10, SIR2 and CCL20. CONCLUSION: We herein report a novel approach based on a non-invasive sampling method combined with the high-throughput protein assay for profiling inflammatory proteins in CL lesions. Using this approach, we could profile inflammatory proteins in the lesions from CL patients. This new non-invasive approach may have implications for studying skin inflammatory mediators in CL and other skin disorders.

Obesity in adolescents does not influence early immune responses to influenza vaccination.

BACKGROUND: Obesity has been linked to reduced vaccine responses against tetanus, hepatitis B and influenza. Data on the influence of paediatric obesity on influenza vaccine response is still lacking and this study aims to fill the gap. METHODS: A total of 30 children with obesity and 30 children with normal weight, aged 12-18 years, were recruited. Participants were vaccinated with a tetravalent influenza vaccine. Blood was collected prior to the vaccination and again four weeks later. The humoral response was assessed with haemagglutinin inhibition assay. The cellular response was assessed with T-cell stimulation assays measuring TNF-α, IFN-γ, IL-2 and IL-13. RESULTS: Of the 29/30 from the study group and 30/30 from the control group finished both visits. Seroconversion occurred for > 90% of participants in both groups for the A/H1N1, A/H3N2 and B/Victoria strains, but the B/Yamagata strain had lower seroconversion rates (93% in the study group and 80% in the control group). 97-100% of participants from both groups had adequate serological responses following vaccination. Cellular responses were similar between the two groups post-vaccination. CONCLUSIONS: Early humoral and cellular immune responses to influenza vaccinations are similar among adolescents with obesity and normal weight.