XMEN saved by magnesium

HLH and Recurrent EBV Lymphoma as the presenting manifestation of MAGT1 Deficiency: A Systematic Review of the Expanding Disease Spectrum

Magnesium transporter 1 (MAGT1) gene loss-of-function variants lead to X-linked MAGT1 deficiency with increased susceptibility to EBV infection and N-glycosylation defect (XMEN), a condition with a variety of clinical and immunological effects. In addition, MAGT1 deficiency has been classified as a congenital disorder of glycosylation (CDG) due to its unique role in glycosylation of multiple substrates including NKG2D, necessary for viral protection. Due to the predisposition for EBV, this etiology has been linked with hemophagocytic lymphohistiocytosis (HLH), however only limited literature exists. Here we present a complex case with HLH and EBV-driven classic Hodgkin lymphoma (cHL) as the presenting manifestation of underlying immune defect. However, the patient's underlying immunodeficiency was not identified until his second recurrence of Hodgkin disease, recurrent episodes of Herpes Zoster, and after he had undergone autologous hematopoietic stem cell transplant (HSCT) for refractory Hodgkin lymphoma. This rare presentation of HLH and recurrent lymphomas without some of the classical immune deficiency manifestations of MAGT1 deficiency led us to review the literature for similar presentations and to report the evolving spectrum of disease in published literature. Our systematic review showcased that MAGT1 predisposes to multiple viruses (including EBV) and adds risk of viral-driven neoplasia. The roles of MAGT1 in the immune system and glycosylation were highlighted through the multiple organ dysfunction showcased by the previously validated Immune Deficiency and Dysregulation Activity (IDDA2.1) score and CDG-specific Nijmegen Pediatric CDG Rating Scale (NPCRS) score for the patient cohort in the systematic review.

Malignancy-associated immune responses: Lessons from human inborn errors of immunity

It is widely understood that cancer is a significant cause of morbidity and mortality worldwide. Despite numerous available treatments, prognosis for many remains poor, thus, the development of novel therapies remains essential. Given the incredible success of many immunotherapies in this field, the important contribution of the immune system to the control, and elimination, of malignancy is clear. While many immunotherapies target higher-order pathways, for example, through promoting T-cell activation via immune checkpoint blockade, the potential to target specific immunological pathways is largely not well researched. Precisely understanding how immunity can be tailored to respond to specific challenges is an exciting idea with great potential, and may trigger the development of new therapies for cancer. Inborn Errors of Immunity (IEI) are a group of rare congenital disorders caused by gene mutations that result in immune dysregulation. This heterogeneous group, spanning widespread, multisystem immunopathology to specific immune cell defects, primarily manifest in immunodeficiency symptoms. Thus, these patients are particularly susceptible to life-threatening infection, autoimmunity and malignancy, making IEI an especially complex group of diseases. While precise mechanisms of IEI-induced malignancy have not yet been fully elucidated, analysis of these conditions can highlight the importance of particular genes, and downstream immune responses, in carcinogenesis and may help inform mechanisms which can be utilised in novel immunotherapies. In this review, we examine the links between IEIs and cancer, establishing potential connections between immune dysfunction and malignancy and suggesting roles for specific immunological mechanisms involved in preventing carcinogenesis, thus, guiding essential future research focused on cancer immunotherapy and providing valuable insight into the workings of the immune system in both health and disease.

The association of serum magnesium with infection in new-onset systemic lupus erythematosus patients

OBJECTIVE

To assess the association of serum magnesium with infection in new-onset systemic lupus erythematosus (SLE) patients.

METHODS

We conducted a single-center retrospective cohort study of new-onset SLE patients from 2012 to 2021. The hospitalized SLE patients were divided into infection and noninfection groups. Logistic regression analysis was conducted to examine the association of hypomagnesemia with infection.

RESULTS

A total of 476 new-onset SLE patients were included, with 299 cases in the infection group and 177 cases in the noninfection group. The patients were mostly females (81.7%). The average age at diagnosis was 43.7 years. The median duration was 1.0 month. The prevalence of hypomagnesemia (<0.70), normomagnesemia (0.70-1.10), and hypermagnesemia (>1.10) in new-onset SLE patients was 14.3%, 83.4%, and 2.3%, respectively. The prevalence of hypomagnesemia was 18.4% in the infection group and 7.3% in the noninfection group (p = .001). The baseline value of serum magnesium was 0.819 mmol/L, with values of 0.799 mmol/L in the infection group and 0.854 mmol/L in the noninfection group (p = .000). The following clinical variables were significantly different between the two groups (p < .05): age, duration, hospitalization stay, fever, serositis, and SLE Disease Activity Index 2000 (SLEDAI 2K). The laboratory parameters, including hemoglobin, white blood cell count, albumin level, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), procalcitonin, and complement C3 were also significantly different between the two groups (p < .05). The mortality was 4.4% (21/476), with 20 cases occurring in the infection group. Logistic regression analysis showed that hypomagnesemia was associated with an increased risk of infection (p = .001) and poor prognosis (p = .015).

CONCLUSION

Hypermagnesemia was rare in new-onset SLE patients. Hypomagnesemia was common and was associated with an increased risk of infection in new-onset SLE patients.

Immune checkpoints in T cells during oncogenic γ-herpesvirus infections

Epstein-Barr virus (EBV) and Kaposi sarcoma-associated herpesvirus (KSHV) are two persistent oncogenic γ-herpesviruses with an exclusive tropism for humans. They cause cancers of lymphocyte, epithelial and endothelial cell origin, such as Burkitt's and Hodgkin's lymphoma, primary effusion lymphoma, nasopharyngeal carcinoma, and Kaposi sarcoma. Mutations in immune-related genes but also adverse events during immune checkpoint inhibition in cancer patients have revealed molecular requirements for immune control of EBV and KSHV. These include costimulatory and coinhibitory receptors on T cells that are currently explored or already therapeutically targeted in tumor patients. This review discusses these co-receptors and their influence on EBV- and KSHV-associated diseases. The respective studies reveal surprising specificities of some of these receptors for immunity to these tumor viruses, benefits of their blockade for some but not other virus-associated diseases, and that EBV- and KSHV-specific immune control should be monitored during immune checkpoint inhibition to prevent adverse events that might be associated with their reactivation during treatment.