C3d-Targeted factor H inhibits tissue complement in disease models and reduces glomerular injury without affecting circulating complement.

Complement-mediated diseases can be treated using systemic inhibitors. However, complement components are abundant in circulation, affecting systemic inhibitors' exposure and efficacy. Furthermore, because of complement's essential role in immunity, systemic treatments raise infection risk in patients. To address these challenges, we developed antibody fusion proteins combining the alternative-pathway complement inhibitor factor H (fH1-5) with an anti-C3d monoclonal antibody (C3d-mAb-2fH). Because C3d is deposited at sites of complement activity, this molecule localizes to tissue complement while minimizing circulating complement engagement. These fusion proteins bind to deposited complement in diseased human skin sections and localize to activated complement in a primate skin injury model. We further explored the pharmacology of C3d-mAb-2fH proteins in rodent models with robust tissue complement activation. Doses of C3d-mAb-2fH >1 mg/kg achieved >75% tissue complement inhibition in mouse and rat injury models while avoiding circulating complement blockade. Glomerular-specific complement inhibition reduced proteinuria and preserved podocyte foot-process architecture in rat membranous nephropathy, indicating disease-modifying efficacy. These data indicate that targeting local tissue complement results in durable and efficacious complement blockade in skin and kidney while avoiding systemic inhibition, suggesting broad applicability of this approach in treating a range of complement-mediated diseases.

A time-continuous land surface temperature (LST) data fusion approach based on deep learning with microwave remote sensing and high-density ground truth observations.

Land surface temperature (LST) is a crucial parameter in the circulation of water, exchange of land-atmosphere energy, and turbulence. Currently, most LST products rely heavily on thermal infrared remote sensing, which is susceptible to cloud and rain interference, leading to inferior temporal continuity. Microwave remote sensing has the advantage of being available "all-weather" due to strong penetration capability, which provides the possibility to simulate time-continuous LST data. In addition, the continuous increase in high-density station observations (>10,000 stations) provides reliable measured data for the remote sensing monitoring of LST in China. This study aims to adopt the "Earth big data" generated from high-density station observation and microwave remote sensing data to monitor LST based on deep learning (U-Net family) for the first time. Given the significant spatial and temporal variability of LST and its sensitivity to various factors according to radiation transmission equations, this study incorporated climatic, anthropogenic, geographical, and vegetation datasets to facilitate a multi-source data fusion approach for LST estimation. The results showed that the U-Net++ model with modified skip connections better minimized the semantic discrepancy between the feature maps of the encoder and decoder subnetworks for 0.1° daily LST mapping across China than the U-Net and U2-Net deep learning models. The accuracy of the LST simulation exhibited favorable outcomes in the spatial and temporal dimensions. The station density met the requirements of monitoring air-ground integration monitoring in China. Additionally, the temporal change in the simulation accuracy fluctuated in a W-shape owing to the limited simulation capability of deep learning in extreme scenarios. Anthropogenic factors had the largest influence on LST changes in China, followed by climate, geography, and vegetation. This study highlighted the application of deep learning in remote sensing monitoring against the background of "big data" and provided a scientific foundation for the response of climate change to human activities, ecological environmental protection, and sustainable social and economic development.

Defective C3d caused by C3 p.W1034R in inherited atypical hemolytic uremic syndrome.

INTRODUCTION: Atypical hemolytic uremic syndrome (aHUS) is a rare form of thrombotic microangiopathy. Personal genome analyses have revealed numerous aHUS-causing variants, mainly complement-related genes. However, not all aHUS-causing variants have been functionally validated. METHODS: An exome sequence analysis of a Japanese multiplex family composed of three patients diagnosed with aHUS in infancy and showing frequent relapses clustered in a dominant transmission mode was performed. Protein interaction between the C3d and C-terminal domains of factor H was analyzed using a quartz crystal microbalance. RESULTS: Following filtering by heterozygous variants, amino acid substitutions, and allele frequency, the analysis revealed eight rare variants shared by the affected individuals. Variant prioritization listed C3 p.W1034R as the most likely candidate gene mutation in the affected individuals, despite being classified as a variant of uncertain significance. Binding of recombinant C3d harboring 1034R to recombinant short consensus repeats 15 to 20 of factor H was significantly suppressed compared with that of C3 with 1034W. CONCLUSION: C3 p.W1034R results in an inherited form of aHUS that often presents with recurrent episodes, possibly because of impaired interactions between the C3d and C-terminal domains of factor H. Following comprehensive genomic analysis, functional validation of C3 p.W1034R strengthens the molecular basis for aHUS pathophysiology.

Immunohistochemical Evaluation of C4d and C3d Markers in Bullous Pemphigoid as a Substitute for Direct Immunofluorescence Technique.

Background: There are several methods for the diagnosis of autoimmune bullous disease. Direct immunofluorescent (DIF) testing is an important diagnostic method in the diagnosis of immunobullous disease but requires skilled pathologist, fresh tissue and well-equipped laboratory to perform the procedure. The immunohistochemistry analysis of C4d and C3d is easily compared with other methods. This study was conducted to assess the value of immunohistochemistry (IHC) analysis for expressions of C3d and C4d in the diagnosis of bullous pemphigoid (BP). Aims and Objectives: This study was conducted to assess the value of immunohistochemistry (IHC) analysis for expressions of C3d and C4d in the diagnosis of bullous pemphigoid (BP). Materials and. Method: We applied C4d and C3d immunohistochemistry on formalin-fixed, paraffin-embedded tissue on 30 cases of bullous pemphigoid that was confirmed by direct immunofluorescence (DIF) evaluation as well as 16 cases in control group (12 cases of herpetiform dermatitis, 3 cases of linear IgA dermatosis and 3 cases of bullous lichen planus). Results: Mean and SD of age were 68.13 ± 14.00, female to male ratio was 1:3. In cases where both C3d and C4d staining were positive, the intensity of C3d staining was higher than C4d. Twenty-two cases showed C4d-positive staining in IHC study, such that in seven cases focal staining and in 15 cases diffuse staining were observed. Also 26 cases showed C3d-positive staining in IHC study such that in four cases focal staining and in 22 cases diffuse staining were observed. In cases with C3d-positive staining, there were 21 cases of deposition only on the bullous floor, one case on the bullous roof and four cases on the bullous roof and floor. In cases with C4d-positive staining, there were 17 cases of deposition on the bullous floor, two cases only on the bullous roof and three cases on the roof and floor. All control cases were negative for C3d and C4d staining in the dermoepidermal junction. For C3d immunohistochemical staining, sensitivity, specificity, positive predictive value and negative predictive value were 86.66%, 100%, 100% and 80%, respectively, and for C4d immunohistochemical staining, respectively, were 73.3%, 100%, 100% and 66.66%. Conclusion: The immunohistochemical specificity of C4d and C3d on tissue blocks is the same as that of direct immunofluorescence test on fresh tissue, but it is less sensitive, so positive results for C3d and C4d immunohistochemical staining on paraffin blocks can be used to confirm the diagnosis of bullous pemphigoid.

Fusion of the molecular adjuvant C3d to cleavage-independent native-like HIV-1 Env trimers improves the elicited antibody response.

An effective HIV vaccine likely requires the elicitation of neutralizing antibodies (NAbs) against multiple HIV-1 clades. The recently developed cleavage-independent native flexibly linked (NFL) envelope (Env) trimers exhibit well-ordered conformation and elicit autologous tier 2 NAbs in multiple animal models. Here, we investigated whether the fusion of molecular adjuvant C3d to the Env trimers can improve B- cell germinal center (GC) formation and antibody responses. To generate Env-C3d trimers, we performed a glycine-serine- based (G4S) flexible peptide linker screening and identified a linker range that allowed native folding. A 30-60- amino- acid- long linker facilitates Env-to-C3d association and achieves the secretion of well-ordered trimers and the structural integrity and functional integrity of Env and C3d. The fusion of C3d did not dramatically affect the antigenicity of the Env trimers and enhanced the ability of the Env trimers to engage and activate B cells in vitro. In mice, the fusion of C3d enhanced germinal center formation, the magnitude of Env-specific binding antibodies, and the avidity of the antibodies in the presence of an adjuvant. The Sigma Adjuvant System (SAS) did not affect the trimer integrity in vitro but contributed to altered immunogenicity in vivo, resulting in increased tier 1 neutralization, likely by increased exposure of variable region 3 (V3). Taken together, the results indicate that the fusion of the molecular adjuvant, C3d, to the Env trimers improves antibody responses and could be useful for Env-based vaccines against HIV.

Research on Anomaly Detection of Surveillance Video Based on Branch-Fusion Net and CSAM.

As the monitor probes are used more and more widely these days, the task of detecting abnormal behaviors in surveillance videos has gained widespread attention. The generalization ability and parameter overhead of the model affect how accurate the detection result is. To deal with the poor generalization ability and high parameter overhead of the model in existing anomaly detection methods, we propose a three-dimensional multi-branch convolutional fusion network, named "Branch-Fusion Net". The network is designed with a multi-branch structure not only to significantly reduce parameter overhead but also to improve the generalization ability by understanding the input feature map from different perspectives. To ignore useless features during the model training, we propose a simple yet effective Channel Spatial Attention Module (CSAM), which sequentially focuses attention on key channels and spatial feature regions to suppress useless features and enhance important features. We combine the Branch-Fusion Net and the CSAM as a local feature extraction network and use the Bi-Directional Gated Recurrent Unit (Bi-GRU) to extract global feature information. The experiments are validated on a self-built Crimes-mini dataset, and the accuracy of anomaly detection in surveillance videos reaches 93.55% on the test set. The result shows that the model proposed in the paper significantly improves the accuracy of anomaly detection in surveillance videos with low parameter overhead.

C3d-binding assay for the detection of complement activating HLA antibodies: A useful tool for allocation to highly sensitised recipients in the post-CDC era?

The CDC crossmatch test is being phased out in solid organ donor allocation, and standard luminex single antigen bead assays do not differentiate complement activating function of HLA antibodies. The current study investigated the LIFECODES C3d-binding assay to determine if it could accurately predict actual T and B cell CDC results in a cohort of highly sensitised patients. Nineteen serum samples from different highly sensitised solid organ patients were crossmatched against cells from 62 unique donors, with 174 total T and B cell crossmatches performed. The sera also underwent SAB assay using OLI and LC platforms, and C3d-binding assay. Complement activating ability of each unique HLA antibody specificity detected using SAB was assigned based on the actual CDC results, which was then used to determine the accuracy of the C3d-binding assay. The C3d-binding assay was found to be highly accurate, with sensitivity of 95%, specificity 89% and negative predictive value 97% for class I DSA and the T cell CDC crossmatch results. Furthermore, we found 100% accuracy for prediction of the complement activating function of HLA-C antibodies. Negative predictive value of above 90% was also found for HLA class II DSA. C3d-binding proved more accurate than virtual crossmatch alone to predict CDC results. This study confirms that the C3d-binding assay predicts actual CDC crossmatch results accurately. In particular, the high negative predictive value of the C3d-binding assay may be extremely useful to define HLA antibodies that do not activate complement in highly sensitised recipients.

Analyses of the clinical and immunological characteristics of patients with lupus erythematosus.

Background: Lupus erythematosus (LE) is a broad-spectrum, heterogeneous disease. At one end of the spectrum is the cutaneous LE (CLE) without systemic involvement, and at the other end is the systemic LE (SLE) with multisystem involvement. Analyses of clinical and immunological indicators and pathological examinations are helpful for early diagnosis, differential diagnosis, and prognosis of LE. Aim and Objectives: We described the clinical and laboratory characteristics of patients with LE and assessed the diagnostic value of immunohistochemical detection of C3d, C4d, IgG, IgG4, and CD123 in skin lesions of LE. Materials and Methods: Clinical and laboratory data of 62 patients with LE were collected. The expression levels of C3d, C4d, IgG, IgG4, and CD123 in skin lesions of LE were detected by immunohistochemistry (IHC). Results: Clinical manifestations such as hematological involvement, C3, C4, ESR, hematuresis, proteinuria, anti-Sm, anti-ribosomal P-protein, anti-U1-RNP, anti-histone, and anti-nucleosome antibodies are helpful for classificatory diagnosis of LE. The positive rate of C3d and/or C4d along the basement membrane zone in LE skin lesions by IHC was 74.6%, which was higher than that by direct immunofluorescence (47.5%) (P = 0.002). The expression of CD123 protein and the number of CD123+ plasmacytoid dendritic cells (PDCs) in skin lesions of patients with LE were higher than those of dermatomyositis (DM), while the distributed form of CD123 + PDCs in the dermis was different between LE and DM. Conclusions: The diagnosis of CLE and SLE requires a combination of clinical manifestations, laboratory indicators, and pathological examination. Immunohistochemical detection of C3d, C4d, and CD123 in skin lesions is important for the classificatory diagnosis of LE.

Development and Optimization of Bifunctional Fusion Proteins to Locally Modulate Complement Activation in Diseased Tissue.

Sustained complement activation is an underlying pathologic driver in many inflammatory and autoimmune diseases. Currently approved anti-complement therapies are directed at the systemic blockade of complement. Consequently, these therapies provide widespread inhibition of complement pathway activity, beyond the site of ongoing activation and the intended pharmacodynamic (PD) effects. Given the essential role for complement in both innate and adaptive immunity, there is a need for therapies that inhibit complement in diseased tissue while limiting systemic blockade. One potential approach focuses on the development of novel fusion proteins that enable tissue-targeted delivery of complement negative regulatory proteins. These therapies are expected to provide increased potency and prolonged tissue PD, decreased dosing frequency, and the potential for improved safety profiles. We created a library of bifunctional fusion proteins that direct a fragment of the complement negative regulator, complement receptor type 1 (CR1) to sites of tissue injury. Tissue targeting is accomplished through the binding of the fusion protein to complement C3 fragments that contain a surface-exposed C3d domain and which are covalently deposited on tissues where complement is being activated. To that end, we generated a fusion protein that contains an anti-C3d monoclonal antibody recombinantly linked to the first 10 consensus repeats of CR1 (CR11-10) with the intention of delivering high local concentrations of this complement negative regulatory domain to tissue-bound complement C3 fragments iC3b, C3dg and C3d. Biochemical and in vitro characterization identified several fusion proteins that inhibit complement while maintaining the C3d domain binding properties of the parent monoclonal antibody. Preclinical in vivo studies further demonstrate that anti-C3d fusion proteins effectively distribute to injured tissue and reduce C3 fragment deposition for periods beyond 14 days. The in vitro and in vivo profiles support the further evaluation of C3d mAb-CR11-10 as a novel approach to restore proper complement activation in diseased tissue in the absence of continuous systemic complement blockade.

Staphylococcal Complement Evasion Protein Sbi Stabilises C3d Dimers by Inducing an N-Terminal Helix Swap.

Staphylococcus aureus is an opportunistic pathogen that is able to thwart an effective host immune response by producing a range of immune evasion molecules, including S. aureus binder of IgG (Sbi) which interacts directly with the central complement component C3, its fragments and associated regulators. Recently we reported the first structure of a disulfide-linked human C3d17C dimer and highlighted its potential role in modulating B-cell activation. Here we present an X-ray crystal structure of a disulfide-linked human C3d17C dimer, which undergoes a structurally stabilising N-terminal 3D domain swap when in complex with Sbi. These structural studies, in combination with circular dichroism and fluorescence spectroscopic analyses, reveal the mechanism underpinning this unique helix swap event and could explain the origins of a previously discovered N-terminally truncated C3dg dimer isolated from rat serum. Overall, our study unveils a novel staphylococcal complement evasion mechanism which enables the pathogen to harness the ability of dimeric C3d to modulate B-cell activation.

Potential Involvement of Complement Activation in Kidney Vascular Lesions of Arterionephrosclerosis.

Background: Complement dysregulation has been implicated in the pathogenesis of malignant nephrosclerosis with typical pathological manifestation as thrombotic microangiopathy (TMA) in recent studies. The aim of the present study was to evaluate the potential role of complement activation in arterionephrosclerosis, the major pathological change in benign hypertensive nephrosclerosis. Methods: Patients with biopsy-proven arterionephrosclerosis from 2010 to 2018 in our center were retrospectively enrolled in the present study. The clinical data were retrieved from the medical chart record. The pathological changes of renal biopsy were semiquantitatively evaluated. The ratio of inner-/outer-luminal diameter of the arterioles was calculated to evaluate the degree of arteriosclerosis. Immunohistochemical staining of CD34 and CD68 was adopted to evaluate peritubular capillary (PTC) density and macrophage infiltration, respectively. Complement components, including C3d, C4d, C1q, and C5b-9, were detected by immunohistochemical staining in paraffin-embedded sections. IgM and albumin were detected by immunofluorescence staining in frozen renal tissues. Results: Fifty-two patients were enrolled. The mean age was 45.0 ± 12.7 years, with 39 (75%) males. The median duration of hypertension was 66 months (IQR: 24-138 months). A total of 950 arterioles were evaluated, with a mean ratio of the inner/outer luminal diameter of 0.43 ± 0.05. The ratio of the inner-/outer-luminal diameter correlated with eGFR (r = 0.341, p = 0.013), sclerotic/ischemic glomerular lesions (r = -0.364, p = 0.008) and PTC density (r = 0.426, p = 0.002). Seventy-four percent (703/950) of the evaluated arterioles had C3d deposition with various patterns and intensities. The percentage of C3d-positive arterioles ranged from 63.6 to 100.0% in each specimen. The ratio of the inner/outer luminal diameter of arterioles correlated with the intensity of C3d deposition (r = -0.174, p = 0.001). Infiltration of macrophages was observed around C3d-positive arterioles. The percentage of C3d-positive arterioles was correlated with macrophage infiltration in each specimen (r = 0.330, p = 0.018). Occasional C4d-positive staining on arterioles was observed with no deposition of C1q or C5b-9 in arterionephrosclerosis specimens. Conclusion: Our findings provide evidence for potential complement activation in the pathogenesis of vascular lesions in arterionephrosclerosis.

Blood group discrepancy in mixed-type autoimmune hemolytic anemia in a pediatric patient.

Autoimmune hemolytic anemia (AIHA) is characterized by the presence of antibodies directed against self-antigens on red blood cells (RBCs) leading to progressive RBC destruction along with reduced red cell survival. Mixed-type AIHA is characterized by the presence of both warm and cold-autoantibodies. These autoantibodies may cause blood-group discrepancy or cross-match incompatibility leading to delay in arranging suitable blood unit for transfusion. The detection of autoantibodies by monospecific-direct antiglobulin test showing positive reaction on immunoglobulin G and C3d and presence of cold-agglutinins leads to the diagnosis. We report a rare case of mixed AIHA in a 15 years female showing severe anemia, blood group discrepancy, and cross-match incompatibility. She received transfusion of least incompatible packed RBCs without any untoward effect.

Insights Into the Structure-Function Relationships of Dimeric C3d Fragments.

Cleavage of C3 to C3a and C3b plays a central role in the generation of complement-mediated defences. Although the thioester-mediated surface deposition of C3b has been well-studied, fluid phase dimers of C3 fragments remain largely unexplored. Here we show C3 cleavage results in the spontaneous formation of C3b dimers and present the first X-ray crystal structure of a disulphide-linked human C3d dimer. Binding studies reveal these dimers are capable of crosslinking complement receptor 2 and preliminary cell-based analyses suggest they could modulate B cell activation to influence tolerogenic pathways. Altogether, insights into the physiologically-relevant functions of C3d(g) dimers gained from our findings will pave the way to enhancing our understanding surrounding the importance of complement in the fluid phase and could inform the design of novel therapies for immune system disorders in the future.

Illuminating the COP1/SPA Ubiquitin Ligase: Fresh Insights Into Its Structure and Functions During Plant Photomorphogenesis.

CONSTITUTIVE PHOTOMORPHOGENIC 1 functions as an E3 ubiquitin ligase in plants and animals. Discovered originally in Arabidopsis thaliana, COP1 acts in a complex with SPA proteins as a central repressor of light-mediated responses in plants. By ubiquitinating and promoting the degradation of several substrates, COP1/SPA regulates many aspects of plant growth, development and metabolism. In contrast to plants, human COP1 acts as a crucial regulator of tumorigenesis. In this review, we discuss the recent important findings in COP1/SPA research including a brief comparison between COP1 activity in plants and humans.

B cell targeting by molecular adjuvants for enhanced immunogenicity.

INTRODUCTION: Adjuvants are critical components of vaccines to improve the quality and durability of immune responses. Molecular adjuvants are a specific subclass of adjuvants where ligands of known immune-modulatory receptors are directly fused to an antigen. Co-stimulation of the B cell receptor (BCR) and immune-modulatory receptors through this strategy can augment downstream signaling to improve antibody titers and/or potency, and survival in challenge models. AREAS COVERED: C3d has been the most extensively studied molecular adjuvant and shown to improve immune responses to a number of antigens. Similarly, tumor necrosis superfamily ligands, such as BAFF and APRIL, as well as CD40, CD180, and immune complex ligands can also improve humoral immunity as molecular adjuvants. EXPERT OPINION: However, no single strategy has emerged that improves immune outcomes in all contexts. Thus, systematic exploration of molecular adjuvants that target B cell receptors will be required to realize their full potential as next-generation vaccine technologies.

Gene testing for osteonecrosis of the femoral head in systemic lupus erythematosus using targeted next-generation sequencing: A pilot study.

BACKGROUND: Previous publications indicated that genetic predisposition might play important roles in the onset of osteonecrosis of the femoral head (ONFH) in systemic lupus erythematosus (SLE). Some gene loci such as complement C3d receptor 2 (CR2), nitric oxide synthase 3 (NOS3), collagen type II alpha 1 chain (COL2A1), protein tyrosine phosphatase non-receptor type 22 (PTPN22), and transient receptor potential cation channel subfamily V member 4 (TRPV4) were reported to be involved in this process. AIM: To investigate whether the risk of ONFH in SLE is associated with single nucleotide variations (SNVs) in these five genes. METHODS: SNVs in the CR2, NOS3, COL2A1, PTPN22, and TRPV4 genes were examined by using FastTarget and Illumina Miseq sequencing technologies in 49 cases of SLE with ONFH. Burrows-wheeler aligner was used to align the sequencing reads to hg19, and GATK and Varscan programs were used to perform SNV calling. PolyPhen-2, SIFT, and MutationTaster were used to assess the functional effects of non-synonymous SNVs. RESULTS: Six of the 49 patients were confirmed to have low frequency SNVs, including one patient with SNVs in NOS3 (exon 6: c.814G>A: p.E272K and exon 7: c.814G>A: p.E272K.), four in COL2A1 (rs41263847: exon 29: c.1913C>T: p.T638I, exon 28: c.1706C>T: p.T569I, and rs371445823: exon 8: c.580G>A: p.A194T, exon 7: c.373G>A: p.A125T), and one in CR2 (rs45573035: exon 2: c.200C>G: p.T67S). CONCLUSION: The onset of ONFH in SLE might be associated with the identified SNVs in NOS3, COL2A1, and CR2.

Radiotherapy for the treatment of pituitary adenomas: A dosimetric comparison of three planning techniques.

AIM: Our goal was to compare conformal 3D (C3D) radiotherapy (RT), modulated intensity RT (IMRT), and volumetric modulated arc therapy (VMAT) planning techniques in treating pituitary adenomas. BACKGROUND: RT is important for managing pituitary adenomas. Treatment planning advances allow for higher radiation dosing with less risk of affecting organs at risk (OAR). MATERIALS AND METHODS: We conducted a 5-year retrospective review of patients with pituitary adenoma treated with external beam radiation therapy (C3D with flattening filter, flattening filter-free [FFF], IMRT, and VMAT). We compared dose-volume histogram data. For OARs, we recorded D2%, maximum, and mean doses. For planning target volume (PTV), we registered V95%, V107%, D95%, D98%, D50%, D2%, minimum dose, conformity index (CI), and homogeneity index (HI). RESULTS: Fifty-eight patients with pituitary adenoma were included. Target-volume coverage was acceptable for all techniques. The HI values were 0.06, IMRT; 0.07, VMAT; 0.08, C3D; and 0.09, C3D FFF (p < 0.0001). VMAT and IMRT provided the best target volume conformity (CI, 0.64 and 0.74, respectively; p < 0.0001). VMAT yielded the lowest doses to the optic pathway, lens, and cochlea. The position of the neck in extreme flexion showed that it helps in planning mainly with VMAT by allowing only one arc to be used and achieving the desired conformity, decreasing the treatment time, while allowing greater protection to the organs of risk using C3D, C3DFFF. CONCLUSIONS: Our results confirmed that EBRT in pituitary adenomas using IMRT, VMAT, C3D, C3FFF provide adequate coverage to the target. VMAT with a single arc or incomplete arc had a better compliance with desired dosimetric goals, such as target coverage and normal structures dose constraints, as well as shorter treatment time. Neck extreme flexion may have benefits in treatment planning for better preservation of organs at risk. C3D with extreme neck flexion is an appropriate treatment option when other treatment techniques are not available.

Pelvic radiation therapy with volumetric modulated arc therapy and intensity-modulated radiotherapy after renal transplant: A report of 3 cases.

AIM: Describe characteristics and outcomes of three patients treated with pelvic radiation therapy after kidney transplant. BACKGROUND: The incidence of pelvic cancers in kidney transplant (KT) recipients is rising. Currently it is the leading cause of death. Moreover, treatment is challenging because anatomical variants, comorbidities, and associated treatments, which raises the concern of using radiotherapy (RT). RT has been discouraged due to the increased risk of urethral/ureteral stricture and KT dysfunction. MATERIALS AND METHODS: We reviewed the electronic health records and digital planning system of patients treated with pelvic RT between December 2013 and December 2018 to identify patients with previous KT. CASES DESCRIPTION: We describe three successful cases of KT patients in which modern techniques allowed full standard RT for pelvic malignances (2 prostate and 1 vaginal cancer) with or without elective pelvic nodal RT, without allograft toxicity at short and long follow-up (up to 60 months). CONCLUSION: When needed, RT modern techniques remain a valid option with excellent oncologic results and acceptable toxicity. Physicians should give special considerations to accomplish all OAR dose constraints in the patient's specific setting. Recent publications recommend KT mean dose <4 Gy, but graft proximity to CTV makes this unfeasible. We present 2 cases where dose constraint was not achieved, and to a short follow-up of 20 months renal toxicity has not been documented. We recommend the lowest possible mean dose to the KT, but never compromising the CTV coverage, since morbimortality from recurrent or progressive cancer disease outweighs the risk of graft injury.

C3d-positive donor-specific antibodies have a role in pretransplant risk stratification of cross-match-positive HLA-incompatible renal transplantation: United Kingdom multicentre study.

Anti-HLA-antibody characteristics aid to risk-stratify patients and improve long-term renal graft outcomes. Complement activation by donor-specific antibody (DSA) is an important characteristic that may determine renal allograft outcome. There is heterogeneity in graft outcomes within the moderate to high immunological risk cases (cross-match-positive). We explored the role of C3d-positive DSAs in sub-stratification of cross-match-positive cases and relate to the graft outcomes. We investigated 139 cross-match-positive living-donor renal transplant recipients from four transplant centres in the United Kingdom. C3d assay was performed on serum samples obtained at pretreatment (predesensitization) and Day 14 post-transplant. C3d-positive DSAs were found in 52 (37%) patients at pretreatment and in 37 (27%) patients at Day 14 post-transplant. Median follow-up of patients was 48 months (IQR 20.47-77.57). In the multivariable analysis, pretreatment C3d-positive DSA was independently associated with reduced overall graft survival, the hazard ratio of 3.29 (95% CI 1.37-7.86). The relative risk of death-censored five-year graft failure was 2.83 (95% CI 1.56-5.13). Patients with both pretreatment and Day 14 C3d-positive DSAs had the worst five-year graft survival at 45.5% compared with 87.2% in both pretreatment and Day 14 C3d-negative DSA patients with the relative risk of death-censored five-year graft failure was 4.26 (95% CI 1.79, 10.09). In this multicentre study, we have demonstrated for the first time the utility of C3d analysis as a distinctive biomarker to sub-stratify the risk of poor graft outcome in cross-match-positive living-donor renal transplantation.