HLA and skin cancer

A simple approach for detecting HLA-A*02 alleles in archival formalin-fixed paraffin-embedded tissue samples and an application example for studying cancer immunoediting

The HLA system represents a central component of the antigen presentation machinery. As every patient possesses a defined set of HLA molecules, only certain antigens can be presented on the cell surface. Thus, studying HLA type-dependent antigen presentation can improve the understanding of variation in susceptibility to various diseases, including infectious diseases and cancer. In archival formalin-fixed paraffin-embedded (FFPE) tissue, the HLA type is difficult to analyze because of fragmentation of DNA, hindering the application of commonly used assays that rely on long DNA stretches. Addressing these difficulties, we present a refined approach for characterizing presence or absence of HLA-A*02, the most common HLA-A allele in the Caucasian population, in archival samples. We validated our genotyping strategy in a cohort of 90 samples with HLA status obtained by an NGS-based method. 90% (n = 81) of the samples could be analyzed with the approach. For all of them, the presence or absence of HLA-A*02 alleles was correctly determined with the method, demonstrating 100% sensitivity and specificity (95% CI: 91.40%-100% and 91.19%-100%). Furthermore, we provide an example of application in an independent cohort of 73 FFPE microsatellite-unstable (MSI) colorectal cancer samples. As MSI cancer cells encompass a high number of mutations in coding microsatellites, leading to the generation of highly immunogenic frameshift peptide antigens, they are ideally suited for studying relations between the mutational landscape of tumor cells and interindividual differences in the immune system, including the HLA genotype. Overall, our method can help to promote studying HLA type-dependency during the pathogenesis of a wide range of diseases, making archival and historic tissue samples accessible for identifying HLA-A*02 alleles.

The Immunogenetics of Non-melanoma Skin Cancer

Non-melanoma skin cancer (NMSC) is the most common malignancy seen in Caucasians and includes basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). The incidence of NMSC is showing an increasing trend which is attributed to the increased use of sunbeds, recreational sun exposure, aging population, and partly to improved screening and reporting. Ultraviolet (UV) radiation plays the most crucial role in the pathogenesis of both BCC and SCC by inducing DNA damage and mutagenic photoproducts. Other risk factors are fair skin, old age, genetic predisposition, immunosuppression, ionizing radiation, organic chemicals, and HPV infection. The role of genomic instability, genetic mutations/aberrations, and host immunity has been fairly illustrated in several studies. This chapter aims to discuss these aspects of NMSC in detail.

Computing Skin Cutaneous Melanoma Outcome From the HLA-Alleles and Clinical Characteristics

Human leukocyte antigen (HLA) are essential components of the immune system that stimulate immune cells to provide protection and defense against cancer. Thousands of HLA alleles have been reported in the literature, but only a specific set of HLA alleles are present in an individual. The capability of the immune system to recognize cancer-associated mutations depends on the presence of a particular set of alleles, which elicit an immune response to fight against cancer. Therefore, the occurrence of specific HLA alleles affects the survival outcome of cancer patients. In the current study, prediction models were developed, using 401 cutaneous melanoma patients, to predict the overall survival (OS) of patients using their clinical data and HLA alleles. We observed that the presence of certain favorable superalleles like HLA-B∗55 (HR = 0.15, 95% CI 0.034-0.67), HLA-A∗01 (HR = 0.5, 95% CI 0.3-0.8), is responsible for the improved OS. In contrast, the presence of certain unfavorable superalleles such as HLA-B∗50 (HR = 2.76, 95% CI 1.284-5.941), HLA-DRB1∗12 (HR = 3.44, 95% CI 1.64-7.2) is responsible for the poor survival. We developed prediction models using key 14 HLA superalleles, demographic, and clinical characteristics for predicting high-risk cutaneous melanoma patients and achieved HR = 4.52 (95% CI 3.088-6.609, p-value = 8.01E-15). Eventually, we also provide a web-based service to the community for predicting the risk status in cutaneous melanoma patients (https://webs.iiitd.edu.in/raghava/skcmhrp/).

Association between Human Leukocyte Antigen Type and Keratinocyte Carcinoma Risk in Renal Transplant Recipients

Keratinocyte carcinoma (KC), defined as squamous cell carcinoma and basal cell carcinoma, is the most common malignancy among white, non-Hispanic renal transplant recipients. Although recent genome-wide association studies reported that class II HLA is associated with KC risk, epidemiologic data on HLA type and KC risk in renal transplant recipients is limited. Using an institutional cohort of white, non-Hispanic renal transplant recipients transplanted between 1993 and 2017, we examined the association between pretransplant molecular HLA types and KC risk. Posttransplant KCs were captured using the International Classification of Diseases codes and validated using pathology reports. Cox proportional hazards regression models were used to estimate hazard ratios of incident KC, squamous cell carcinoma, and basal cell carcinoma, adjusting for age, male sex, history of KC, Charlson comorbidity index, HLA mismatch, transplant type, year of transplant, and the type of immunosuppression. Among 617 subjects (mean age 53 years, 67% male), 10% developed posttransplant KC. Multivariable Cox regression analyses showed HLA-DRB1∗13 was associated with KC risk (hazard ratio, 1.84; 95% confidence interval, 1.00-3.38) and squamous cell carcinoma risk (hazard ratio, 2.24; 95% confidence interval, 1.12-4.49), whereas HLA-DRB1∗14 (hazard ratio, 2.81; 95% confidence interval, 1.14-6.91) was associated with basal cell carcinoma risk. Our findings suggest that a subset of renal transplant recipients with specific HLA polymorphisms may be at increased KC risk.

Keratinocyte Carcinomas: Current Concepts and Future Research Priorities

Cutaneous squamous cell carcinoma (cSCC) and basal cell carcinoma (BCC) are keratinocyte carcinomas, the most frequently diagnosed cancers in fair-skinned populations. Ultraviolet radiation (UVR) is the main driving carcinogen for these tumors, but immunosuppression, pigmentary factors, and aging are also risk factors. Scientific discoveries have improved the understanding of the role of human papillomaviruses (HPV) in cSCC as well as the skin microbiome and a compromised immune system in the development of both cSCC and BCC. Genomic analyses have uncovered genetic risk variants, high-risk susceptibility genes, and somatic events that underlie common pathways important in keratinocyte carcinoma tumorigenesis and tumor characteristics that have enabled development of prediction models for early identification of high-risk individuals. Advances in chemoprevention in high-risk individuals and progress in targeted and immune-based treatment approaches have the potential to decrease the morbidity and mortality associated with these tumors. As the incidence and prevalence of keratinocyte carcinoma continue to increase, strategies for prevention, including effective sun-protective behavior, educational interventions, and reduction of tanning bed access and usage, are essential. Gaps in our knowledge requiring additional research to reduce the high morbidity and costs associated with keratinocyte carcinoma include better understanding of factors leading to more aggressive tumors, the roles of microbiome and HPV infection, prediction of response to therapies including immune checkpoint blockade, and how to tailor both prevention and treatment to individual risk factors and needs.

Exposure and sun protection practices of university students

OBJECTIVE

to learn exposure and sun protection practices for university students.

METHOD

a descriptive, cross-sectional study performed at a university in São Paulo.

RESULTS

the sample consisted of 385 young and data collection conducted through a form. Of the total, 239 (62%) young people were classified as skin type III and IV and 69 (17.9%) affirmed to have a history of skin cancer in the family. Most affirmed exposure to the sun between 10 a.m and 04 p.m and for more than one hour; 112 (29.1%) informed not employ safeguards. Among those who use sunscreen, the minority does so regularly.

CONCLUSION

although the sample was made up of people with greater access to information, it was found exposure and sunscreen improperly. Education, individual and collective actions should be strengthened and prioritized given the incidence of skin cancer in the country.

The Influence of HLA and KIR Genes on Malignant Melanoma Development and Progression

Many studies have described the role of killer immunoglobulin-like receptors (KIRs) and their cognate human leukocyte antigen (HLA) class I ligands in the immune protection against melanoma, but the effect of these markers on intra-individual variations in tumor development and progression has remained less clear. We performed KIR, HLA, and KIR/ligand analysis in 283 patients with malignant melanoma in order to evaluate their integrated influence on disease stage and progression. The patients were grouped according to AJCC staging, histological type of the primary tumor, progression, and survival rate. Analysis of HLA class I alleles revealed positive association of HLA-C*14 (Pc = 0.026, OR = 5.99) and negative association of HLA-C*02 (Pc = 0.026, OR = 0.43) with the disease. Decreased frequency of KIR2DS5 was observed in patients with rapid progression, as compared to those with slow progression. KIR BB genotype was prevalent in patients with metastasis (p = 0.004, OR = 0.025). KIR AA genotype was nearly twice as frequent in rapidly progressive cases, but without statistical relevance (p = 0.055, OR = 2.6). Significantly increased frequency of KIR2DL2 in the presence of C1 ligand (strong inhibition) was found in patients with AJCC III and IV, as compared to individuals with AJCC I stage (p = 0.045, OR = 1.93). In summary, our data imply that KIR/ligand gene content in patients could modulate the disease course towards unfavorable tumor behavior.

Clinical Role of Human Leukocyte Antigen in Health and Disease

Most of the genes in the major histocompatibility complex (MHC) region express high polymorphism that is fundamental for their function. The most important function of human leukocyte antigen (HLA) molecule is in the induction, regulation of immune responses and the selection of the T cell repertoire. A clinician's attention is normally drawn to a system only when it malfunctions. The HLA system is no exception in this regard, but in contrast to other systems, it also arouses interest when it functions well - too well, in fact. Population studies carried out over the last several decades have identified a long list of human diseases that are significantly more common among individuals that carry particular HLA alleles including inflammatory, autoimmune and malignant disorders. HLA-disease association is the name of this phenomenon, and the mechanism underlying is still a subject of hot debate. Social behaviours are affected by HLA genes and preference for HLA disparate mates may provide 'good genes' for an individual's offspring. Also, certain HLA genes may be associated with shorter life and others with longer lifespan, but the effects depend both on the genetic background and on the environmental conditions. The following is a general overview of the important functional aspects of HLA in health and diseases.

Human Leukocyte Antigen Alleles and Cytomegalovirus Infection After Renal Transplantation

Background:

Several studies have been conducted on the relationship between a number of human leukocyte antigen (HLA) alleles and cytomegalovirus infection (CMV), in kidney transplant recipients, after transplantation. However, only a limited number of HLAs have been investigated, so far, and the results have been contradictory.

Objectives:

This study aimed to investigate the relationship between 59 HLA alleles and the CMV infection, in transplant recipients, after kidney transplantation.

Patients and Methods:

This retrospective cohort study was conducted on 200 patients, receiving a kidney transplant, in Baqiyatallah Hospital, in Tehran, during 2013. Throughout a one-year follow-up of kidney transplant recipients, in case of detecting the CMV antigen in patients’ blood, at any time, they were placed in the group of patients with CMV infection, whereas, if no CMV-specific antigen was developed, over a year, patients were placed in the group of patients without CMV infection, after transplantation. This study investigated the relationship between CMV infection in kidney transplant recipients and 59 HLA alleles, including 14 HLA-A, 28 HLA-B, and 17 HLA-DRB1 cases.

Results:

Of all participants, 104 patients (52%) were diagnosed with CMV infection. There was no significant difference between the two groups, with and without CMV infection, in terms of patient’s characteristics. The CMV infection, in patients receiving a transplanted organ from deceased donor, was significantly more prevalent than in those receiving kidney transplant from living donor (63% vs. 39%, respectively, P = 0.001). Recipients with HLA-B44 were more infected with CMV compared with patients without this allele (80% vs. 50%, respectively, P = 0.024); on the contrary, kidney recipients with HLA-DRB1-1 were less infected with CMV than patients without this allele (31% vs. 55%, respectively, P = 0.020). There was no significant relationship between CMV infection and other HLA alleles. Results of multivariate logistic regression analysis showed that deceased donor renal transplantation (OR = 3.018, 95%CI: 1.662 - 5.480, P < 0.001), presence of HLA-B44 (OR = 4.764, 95%CI: 1.259 - 18.032, P = 0.022) and lack of HLA-B8 (OR = 3.246, 95%CI: 1.030 - 10.230, P = 0.044) were the independent risk factors for developing CMV infection, after kidney transplantation.

Conclusions:

The findings of this study showed that deceased donor renal transplantation and the presence of HLA-B44 can make the kidney recipient susceptible to CMV infection after kidney transplantation; on the other hand, the presence of HLA-B8 can have a protective effect.

Changes in median ages at death from selected cancer types in relation to HLA-DRB1/DQB1

The median ages at death from cancers between 1985 and 2005 were calculated to demonstrate that inherent anticancer mechanisms may be a common pathway for different cancers. Seventy-eight patients with gastric, liver and lung cancers, were recruited in the solid cancer group. The leukemia group consisted of 31 patients with three main types of leukemia. The controls were 100 healthy individuals. The samples were typed using an HLA-DR/DQ PCR-SSP typing kit. The results showed that the median ages at death from all causes were 64.7 years in 1985 and 70.1 years in 2005. The range of the median ages at death from all cancers was similar to the corresponding value for deaths attributed to all causes. The frequency of DRB1*03 was 9.6% in the solid cancer group and 3.0% in the control group (p<0.05). The frequency of DRB1*04 in the leukemia group were significantly lower than that of the control (p<0.05). DRB1*13 and DQB1*06 frequencies in the leukemia group were significantly higher than those of the controls (p<0.05). It is suggested that inherent anti-cancer mechanisms may be a common pathway for different cancers and are associated with the immune system and HLA.

Giant cell tumor of bone

EDUCATIONAL OBJECTIVES As a result of reading this article, physicians should be able to: 1. Identify at-risk populations for giant cell tumor of bone. 2. Recognize the biology that drives giant cell tumor of bone. 3. Describe modern surgical and adjuvant techniques to effectively treat giant cell tumor of bone. 4. Recognize the complications associated with radiation therapy, poor resection, and adjuvant treatments. Giant cell tumor of bone (GCT) is a benign, locally aggressive bone tumor. Giant cell tumor of bone primarily affects the young adult patient population. The natural history of GCT is progressive bone destruction leading to joint deformity and disability. Surgery is the primary mode of treatment, but GCT has a tendency to recur locally despite a range of adjuvant surgical options. Pulmonary metastasis has been described. However, systemic spread of GCT rarely becomes progressive, leading to death. This review presents the clinicopathologic features of GCT and a historical perspective that highlights the current rationale and controversies regarding the treatment of GCT.