HLA-G14bp ins/del polymorphism and post-transplant weight gain in kidney transplantation: potential implications beyond tolerance

The double-sided of human leukocyte antigen-G molecules in type 1 autoimmune hepatitis

The immunomodulatory effects of HLA-G expression and its role in cancers, human liver infections and liver transplantation are well documented, but so far, there are only a few reports addressing autoimmune liver diseases, particularly autoimmune hepatitis (AIH).

Biological Characteristics of HLA-G and Its Role in Solid Organ Transplantation

Organ transplantation is a lifesaving option for patients with advanced diseases. Rejection is regarded as one of the most severe risk factors post-transplantation. A molecule that contributes to immune tolerance and resisting rejection is human leukocyte antigen (HLA)-G, which belongs to the non-classical major histocompatibility complex class (MHC) I family. HLA-G was originally found to play a role during pregnancy to maintain immune tolerance between mother and child. It is expressed in the placenta and detected in several body fluids as soluble factor as well as different membrane isoforms on cells. Recent findings on HLA-G show that it can also play multifaceted roles during transplantation. This review will explain the general characteristics and biological function of HLA-G and summarize the views supporting the tolerogenic and other roles of HLA-G to better understand its role in solid organ transplantation (SOT) and its complications. Finally, we will discuss potential future research on the role of HLA-G in prevention, diagnosis, and treatment in SOT.

Weight gain after renal transplant: Incidence, risk factors, and outcomes

Background

Renal transplantation is the definitive treatment for patients with end-stage renal disease (ESRD). It is associated with better quality of life and patient survival. Nevertheless, these benefits come with rising concerns about weight gain and metabolic abnormalities, which adversely impact transplant outcomes.

Objective

The objective of this study is to estimate the incidence of weight gain in the first year post-renal transplant in addition to the assessment of potential risk factors and the resulting outcome of the graft.

Methods

We conducted a single-center retrospective cohort study of all 295 patients who underwent kidney transplantation at King Abdulaziz Medical City (KAMC) between January 2016 and December 2019. Clinical and laboratory variables were collected from electronic records. Continuous variables were reported as mean ± standard deviation. Comparison between groups was assessed by unpaired t-test or Mann-Whitney U test while follow-up data were compared using paired t-test and repeated measures ANOVA. Association between the potential risk factors and the weight gain was assessed by means of binary logistic regression analysis.

Results

Significant weight gain was observed in 161 (54.6%) patients. Females were 119 (40.30%) of the cohort. The mean age was 45.3±15.1 years. The prevalence of diabetes was 234 (79.6%), while hypertensives constituted 77 (26.3%). The comparison between patients who gained weight significantly and patients with stable weight showed a numerical higher prevalence of female gender in patients who had more weight gain (44.1% vs. 35.8%), higher diabetes, higher rate of a living donor, and statistically significant lower dialysis duration before transplant. Other clinical and laboratory variables were comparable between the two groups.

Conclusion

Our study showed a high incidence of clinically significant weight gain among patients post-renal transplantation. Patients with lower dialysis duration, a living kidney donor and those who are obese at baseline were at higher risk of gaining weight. Patients who underwent kidney transplantation should be monitored closely for weight gain and further studies are needed to determine the risk factors and appropriate interventions.

Decreased serum human leukocyte antigen-G levels are associated with gestational diabetes mellitus

AIM

This study was designed to determine serum human leukocyte antigen-G (HLA-G) levels and establish whether serum HLA-G level is related with gestational diabetes mellitus (GDM).

METHODS

Twenty-five GDM patients aged between 24 and 34 years and 24 healthy pregnant women aged between 22 and 33 years were included in this study. Health status of subjects was determined by medical history, physical, and obstetric examinations. Absence of family history for Type 2 diabetes mellitus, absence of diagnosis or clinical evidence of any major disease, and absence of medication use altering glucose metabolism constituted the inclusion criteria. GDM cases who are at their 24-28 weeks of pregnancy and who have not been using any oral hypoglycemic agents were included in GDM group. Control group consisted of healthy pregnant women at their 24-28 weeks of pregnancy.

RESULTS

Women with GDM had significantly lower levels of serum HLA-G than controls. HLA-G levels were negatively correlated with all parameters of glucose metabolism including insulin (r = - 0.14; p = 0.338), fasting blood glucose (r = - 0.220; p = 0.129), 1-h oral glucose tolerance test (OGTT) blood glucose (r = - 0.18; p = 0.271), 2-h OGTT blood glucose (r = - 0.314; p = 0.172), homeostasis model assessment (r = - 0.226; p = 0.119), HbA1C (r = -0.342; p = 0.108), and WBC (r = -0.149; p = 0.307). There was a negative correlation between HLA-G and BMI (r = -0.341; p = 0.016).

CONCLUSION

Decreased circulating HLA-G level is found to be associated with insulin resistance and GDM, in this study.