Late-onset enteric virus infection associated with hepatitis (EVAH) in transplanted SCID patients

BACKGROUND

Allogenic hematopoietic stem cell transplantation (HSCT) and gene therapy (GT) are potentially curative treatments for severe combined immunodeficiency (SCID). Late-onset posttreatment manifestations (such as persistent hepatitis) are not uncommon.

OBJECTIVE

We sought to characterize the prevalence and pathophysiology of persistent hepatitis in transplanted SCID patients (SCIDH+) and to evaluate risk factors and treatments.

METHODS

We used various techniques (including pathology assessments, metagenomics, single-cell transcriptomics, and cytometry by time of flight) to perform an in-depth study of different tissues from patients in the SCIDH+ group and corresponding asymptomatic similarly transplanted SCID patients without hepatitis (SCIDH-).

RESULTS

Eleven patients developed persistent hepatitis (median of 6 years after HSCT or GT). This condition was associated with the chronic detection of enteric viruses (human Aichi virus, norovirus, and sapovirus) in liver and/or stools, which were not found in stools from the SCIDH- group (n = 12). Multiomics analysis identified an expansion of effector memory CD8+ T cells with high type I and II interferon signatures. Hepatitis was associated with absence of myeloablation during conditioning, split chimerism, and defective B-cell function, representing 25% of the 44 patients with SCID having these characteristics. Partially myeloablative retransplantation or GT of patients with this condition (which we have named as "enteric virus infection associated with hepatitis") led to the reconstitution of T- and B-cell immunity and remission of hepatitis in 5 patients, concomitantly with viral clearance.

CONCLUSIONS

Enteric virus infection associated with hepatitis is related to chronic enteric viral infection and immune dysregulation and is an important risk for transplanted SCID patients with defective B-cell function.

Glucagon-like peptide-1 effect on β-cell function varies according to diabetes remission status after Roux-en-Y gastric bypass

AIMS

The contribution of endogenous glucagon-like peptide (GLP)-1 to β-cell function after Roux-en-Y gastric bypass surgery (RYGB) is well established in normoglycaemic individuals, but not in those with postoperative hyperglycaemia. We, therefore, studied the effect of GLP-1 on β-cell function in individuals with varying degrees of type 2 diabetes mellitus (T2D) control after RYGB.

MATERIALS AND METHODS

Glucose, insulin secretion rates, β-cell glucose sensitivity and glucagon were measured during an oral glucose tolerance test before (saline only) and at 3, 12 and 24 months after RYGB with and without infusion of the GLP-1 receptor blocker exendin9-39 (EX9). The cohort was retrospectively classified based on T2D remission (REM) status at the latest study time point: REM (n = 5), persistent T2D (n = 8), or impaired glucose tolerance (n = 16).

RESULTS

EX9 blunted the increase in β-cell glucose sensitivity at 3 months (-44.1%, p < .001) and 12 months (-43.3%, p < .001), but not at 24 months (-12.4%, p = .243). EX9 enhanced postprandial glucagon concentrations by 62.0% at 3 months (p = .008), 46.5% at 12 months (p = .055), and 30.4% at 24 months (p = .017). EX9 counterintuitively decreased glucose concentrations at 3 months in the entire cohort (p < .001) but had no effect on glycaemia at 12 and 24 months in persistent T2D and impaired glucose tolerance; it minimally worsened glycaemia in REM at 12 months.

CONCLUSIONS

GLP-1 blockade reversed the improvement in β-cell function observed after RYGB, but this effect varied temporally and by REM status. GLP-1 blockade transiently and minimally worsened glycaemia only in REM, and lowered postprandial glucose values at 3 months, regardless of REM status.

Latent Autoimmune Diabetes in Adults: Current Status and New Horizons

Autoimmune diabetes is a heterogeneous disease which can arise at any age. Subjects with adult-onset autoimmune diabetes who do not necessitate insulin-therapy for at least 6 months after diagnosis are demarcated as having latent autoimmune diabetes in adults (LADA). This condition is more heterogeneous than young-onset autoimmune diabetes and shares clinical and metabolic characteristics with both type 2 and type 1 diabetes. Patients with LADA are considered by having highly variable β-cell destruction, different degrees of insulin resistance and heterogeneous titre and pattern of islet autoantibody, suggesting different pathophysiological pathways partially explaining the heterogeneous phenotypes of LADA. To date the heterogeneity of LADA does not allow to establish a priori treatment algorithm and no specific guidelines for LADA therapy are available. These subjects are mostly treated as affected by type 2 diabetes, a factor that might lead to the progression to insulin-dependency quickly. A personalised medicine approach is necessary to attain optimal metabolic control and preserve β-cell function to decrease the risk of long-term diabetes complications. Recent data concerning the use of oral antidiabetic agents as dipeptidyl peptidase 4 inhibitors and glucagon-like peptide 1 receptor agonists indicate up-and-coming results in term of protect C-peptide levels and improving glycaemic control. This review summarises current knowledge on LADA, emphasising controversies regarding its pathophysiology and clinical features. Moreover, we discuss data available about novel therapeutic approaches that can be considered for prevention of β-cell loss in LADA.

Effect of GLP-1 and GIP on C-peptide secretion after glucagon or mixed meal tests: Significance in assessing B-cell function in diabetes

BACKGROUND

The aim of the study was to investigate the different B-cell responses after a glucagon stimulation test (GST) versus mixed meal tolerance test (MMTT).

METHODS

We conducted GST and MMTT in 10 healthy people (aged 25-40 years) and measured C-peptide, gastric inhibitory peptide (GIP) and glucagon-like peptide-1 (GLP-1) at different time points after the administration of 1 mg i.v. glucagon for GST or a liquid mixed meal for MMTT.

RESULTS

The GST stimulated C-peptide showed a mean increase of 147.1%, whereas the mean increase of MMTT stimulated C-peptide was 99.82% (Δincrease = 47.2%). Maximum C-peptide level reached with the MMTT was greater than that obtained with the GST (C-pept max MMTT = 2.35 nmol/L vs C-pep max GST = 1.9 nmol/L). A positive and linear correlation was found between the GST incremental area under the curve C-peptide and the MMTT incremental area under the curve C-peptide (r = 0.618, P = .05). After GST, there was no increment of GIP and glucagon like peptide-1 levels compared to baseline levels. A positive and linear correlation between GIP and C-peptide levels was observed only for the MMTT (r = 0.922, P = .008) indicating that in the GST, the C-peptide response is independent of the incretin axis response.

CONCLUSIONS

Although the 2 stimulation tests may elicit a similar response in C-peptide secretion, B-cell response to MMTT depends on a functionally normal incretin axis. These results may have implications when investigating the B-cell response in people with diabetes and for studies in which stimulated C-peptide secretion is used as primary or secondary outcome for response to therapy.

How Cancers Escape Immune Destruction and Mechanisms of Action for the New Significantly Active Immune Therapies: Helping Nonimmunologists Decipher Recent Advances

With the Food and Drug Administration and other worldwide regulatory authorities' approval of ipilimumab (Yervoy), sipuleucel-T (Provenge), nivolumab (Opdivo), and pembrolizumab (Keytruda), oncologic therapy has now moved into noncancer cell targets within the immune system. For many nonimmunologists, understanding how these vastly different therapies work to improve survival, like no other therapies have in the past, is a challenge. The present report reviews the normal function of the immune system, how cancers escape the normal immune system, and how these new therapies improve immune system reactions against cancers.

IMPLICATIONS FOR PRACTICE

Oncologists have tremendous experience with therapies that target the cancer cells. New biologic agents have been rapidly introduced recently that target not cancer cells, but the patient's immune cells. The mechanisms of action of these immune-based biologic agents are within the host immune system. To understand these new biologic therapies, basic knowledge of normal and abnormal immune function is essential. The present report explains the up-to-date basic immune normal and abnormal function and prepares the oncologist to understand how the new drugs work, why they work, and why there are associated adverse events.