Histomorphological view of the cornea investigated by laser confocal microscopy in keratoplasty

Introduction. Corneal transplantation is the most successful and commonly performed allotransplantation procedure as compared with other organs and tissues. Over 100,000 corneal transplantations are performed worldwide every year.Purpose. This study investigated whether in vivo confocal microscopy (IVCM) can aid in the diagnosis of a graft rejection reaction by detecting changes in cellular structures and density of immune cells after penetrating keratoplasty.Materials and methods. The study included thirty-four eyes of 34 patients who underwent penetrating keratoplasty (7 eyes with corneal graft rejection, 27 without rejection). The average age of patients is 51.1 ± 13.6 years (from 23 to 76 years). The follow-up period ranged from 12 to 36 months (24.5 ± 4.84 months). Follow-up was performed at 1, 3, 6, 12 months and annually after PKP. To study the morphology of the cornea all patients underwent IVCM to assess the basal epithelium, subbasal layer, stroma and endothelium. Immune cells were identified and evaluated for the shape, length of the processes and their density.Results. Patients with corneal graft rejection demonstrated significant accumulation of corneal dendritic-like immune cells compared to patients with non-rejected grafts. In addition, the cells acquired a more mature morphology (grade 2–3). The density of dendritic cells (DC) was 809.17 ± 342.19 (p < 0.001). A positive correlation was found between DC density and graft rejection (p < 0.001). As well the patients showed signs of endothelial failure with low endothelial cell density and pleomorphism, increased light scattering and hyperreflectivity of the stroma.Conclusions. In a complex of diagnostic measures, confocal microscopy may provide a valuable clinical adjunctive tool in diagnosis and management of early corneal graft rejection.

Computational Prediction of Biomarkers, Pathways, and New Target Drugs in the Pathogenesis of Immune-Based Diseases Regarding Kidney Transplantation Rejection

BackgroundThe diagnosis of graft rejection in kidney transplantation (KT) patients is made by evaluating the histological characteristics of biopsy samples. The evolution of omics sciences and bioinformatics techniques has contributed to the advancement in searching and predicting biomarkers, pathways, and new target drugs that allow a more precise and less invasive diagnosis. The aim was to search for differentially expressed genes (DEGs) in patients with/without antibody-mediated rejection (AMR) and find essential cells involved in AMR, new target drugs, protein-protein interactions (PPI), and know their functional and biological analysis.Material and MethodsFour GEO databases of kidney biopsies of kidney transplantation with/without AMR were analyzed. The infiltrating leukocyte populations in the graft, new target drugs, protein-protein interactions (PPI), functional and biological analysis were studied by different bioinformatics tools.ResultsOur results show DEGs and the infiltrating leukocyte populations in the graft. There is an increase in the expression of genes related to different stages of the activation of the immune system, antigenic presentation such as antibody-mediated cytotoxicity, or leukocyte migration during AMR. The importance of the IRF/STAT1 pathways of response to IFN in controlling the expression of genes related to humoral rejection. The genes of this biological pathway were postulated as potential therapeutic targets and biomarkers of AMR. These biological processes correlated showed the infiltration of NK cells and monocytes towards the allograft. Besides the increase in dendritic cell maturation, it plays a central role in mediating the damage suffered by the graft during AMR. Computational approaches to the search for new therapeutic uses of approved target drugs also showed that imatinib might theoretically be helpful in KT for the prevention and/or treatment of AMR.ConclusionOur results suggest the importance of the IRF/STAT1 pathways in humoral kidney rejection. NK cells and monocytes in graft damage have an essential role during rejection, and imatinib improves KT outcomes. Our results will have to be validated for the potential use of overexpressed genes as rejection biomarkers that can be used as diagnostic and prognostic markers and as therapeutic targets to avoid graft rejection in patients undergoing kidney transplantation.

To Compare the Graft Uptake in Permeatal versus Postaural Approaches in Myringoplasty

Objective: To compare the graft uptake in permeatal versus postaural approaches in myringoplasty. Study design: Cross sectional comparative Place and Duration of Study: Department of ENT, Head and Neck Surgery, Pakistan Institute of Medical Sciences/Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad Pakistan from 1st March 2018 to 31st December 2018. Methodology: Seventy two patients were classified into two equal groups. Thirty six patients underwent myringoplasty by permeatal approach and thirty six patients underwent postaural approach. Those patients were included who had mucosal type moderate central perforation with inactive disease with age 15-42 years and those patients were excluded who had small, subtotal, total, squamosal type atticoantral tympanic membrane perforation, with comorbidities and pregnancy. Results: Thirty seven were (51.4 %) males and 35 (48.6%) were females. In both the groups the success of graft uptake was 52 (72.2%) patients and graft rejection in 20 (27.8%) patients. In each group there were 36 patients. The graft uptake in permeatal approach was 30 patients (83.3%), while the graft uptake in postaural approach was 22 (61.1%) patients. The overall graft uptake in permeatal approach is more as compared to postaural approach (p=0.035). Conclusion: The permeatal approach is better than the postaural approach in terms of graft uptake in medium sized central perforations in myringoplasty. Key words: Myringoplasty, Tympanoplasty, Permeatal, Postauricular

Tacrolimus trough levels in kidney transplant recipients

Background It is very important that kidney transplant recipients (KTRs) take immunosuppressive drugs to prevent graft rejection. This study aimed to identify the tacrolimus trough levels (TTL)-mean, TTL-standard deviation (SD), and TTL- coefficient of variation (CV) as well as factors affecting these values over a 2-year period in clinically stable patients > 5 years after kidney transplantation (KT). Methods This retrospective study analyzed data from 248 adult outpatients > 5 years after KT. Medical chart data, including TTL, graft rejection, and tacrolimus dose change during a 2-year period, between January 2017 and December 2018, were collected. Multivariable regression analyses were conducted to determine the factors influencing the TTL-mean, TTL-SD, and TTL-CV. Results The TTL-mean, TTL-SD, and TTL-CV were 6.00 ± 1.07 ng/mL, 1.51 ± 1.09 ng/mL, and 0.25 ± 0.14, respectively. The TTL-mean, TTL-SD, and TTL-CV did not differ according to sex, type of donor, retransplant, pretransplant kidney disease, body mass index, or posttransplant time; hence, they are stable in kidney transplant recipients > 5 years after KT. The higher the TTL-mean, the higher the TTL-SD. Age and the TTL-SD significantly predicted the TTL-mean (p < .001). Tacrolimus dose change and the TTL-mean significantly predicted the TTL-SD (p < .001). Tacrolimus dose change significantly predicted the TTL-CV (p = .008). Conclusion In clinically stable KTRs, TTL-SD and TTL-CV change sensitively in relation to tacrolimus dose changes. Therefore, changes in TTL-SD and TTL-CV in stable KTRs with no tacrolimus dose change require medical interest and attention.

Early Myeloid Derived Suppressor Cells (eMDSCs) Are Associated With High Donor Myeloid Chimerism Following Haploidentical HSCT for Sickle Cell Disease

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is a widely available curative option for patients with sickle cell disease (SCD). Our original non-myeloablative haplo-HSCT trial employing post-transplant (PT) cyclophosphamide had a low incidence of GVHD but had high rejection rates. Here, we aimed to evaluate immune reconstitution following haplo-HSCT and identify cytokines and cells associated with graft rejection/engraftment. 50 cytokines and 10 immune cell subsets were screened using multiplex-ELISA and flow cytometry, respectively, at baseline and PT-Days 30, 60, 100, and 180. We observed the most significant differences in cytokine levels between the engrafted and rejected groups at PT-Day 60, corresponding with clinical findings of secondary graft rejection. Of the 44 cytokines evaluated, plasma concentrations of 19 cytokines were different between the two groups at PT-Day 60. Factor analysis suggested two independent factors. The first factor (IL-17A, IL-10, IL-7, G-CSF, IL-2, MIP-1a, VEGF, and TGFb1 contributed significantly) was strongly associated with engraftment with OR = 2.7 (95%CI of 1.4 to 5.4), whereas the second factor (GROa and IL-18 contributed significantly) was not significantly associated with engraftment. Sufficient donor myeloid chimerism (DMC) is critical for the success of HSCT; here, we evaluated immune cells among high (H) DMC (DMC≥20%) and low (L) DMC (DMC&lt;20%) groups along with engrafted and rejected groups. We found that early myeloid-derived suppressor cell (eMDSC) frequencies were elevated in engrafted patients and patients with HDMC at PT-Day 30 (P&lt; 0.04 &amp; P&lt; 0.003, respectively). 9 of 20 patients were evaluated for the source of eMDSCs. The HDMC group had high mixed chimeric eMDSCs as compared to the LDMC group (P&lt; 0.00001). We found a positive correlation between the frequencies of eMDSCs and Tregs at PT-Day 100 (r=0.72, P &lt;0.0007); eMDSCs at BSL and Tregs at PT-Day 100 (r=0.63, P &lt;0.004). Of 10 immune regulatory cells and 50 cytokines, we observed mixed chimeric eMDSCs and IL-17A, IL-10, IL-7, G-CSF, IL-2, MIP-1a, VEGF, TGFb1 as potential hits which could serve as prognostic markers in predicting allograft outcome towards engraftment following haploidentical HSCT employing post-transplant cyclophosphamide. The current findings need to be replicated and further explored in a larger cohort.

Acute corneal graft rejection after anti-severe acute respiratory syndrome-coronavirus-2 vaccination: A report of four cases

Purpose This study intends to add to previous reports on acute corneal graft rejection following anti-severe acute respiratory syndrome-coronavirus-2 vaccination, providing data to corroborate a possible causative relationship between anti-COVID-19 immunization and corneal graft rejection, regardless of vaccine or graft type. Methods and Results This report describes 4 cases of acute-onset rejection as early as 5 days following the first dose of anti-severe acute respiratory syndrome-coronavirus-2 vaccine types not yet referred for corneal allograft. Patients were individually given the Moderna messenger RNA-1273 COVID-19 vaccine (2 patients) and the AstraZeneca COVID-19 vaccine, Vaxzevria, AZD1222 (2 patients). Conclusions Even though a direct causative effect is hard to prove, temporal proximity between anti-severe acute respiratory syndrome-coronavirus-2 vaccines of different types and consecutive reports of corneal graft rejection indicates the need for further investigation. Consistent advice must be given to corneal transplant patients regarding such risk.