Precision medicine for pancreatic diseases

Unraveling the immunological landscape in acute pancreatitis progression to sepsis: insights from a Mendelian randomization study on immune cell traits

Background

Acute pancreatitis (AP) is a severe digestive system disorder with a significant risk of progressing to sepsis, a major cause of mortality. Unraveling the immunological pathways in AP is essential for developing effective treatments, particularly understanding the role of specific immune cell traits in this progression.

Methods

Employing a bidirectional two-sample Mendelian Randomization (MR) approach, this study first examined the causal relationship between AP and 731 immune cell traits to identify those significantly associated with AP. Subsequently, we explored the causal associations between 731 immune cell traits and sepsis. The analysis utilized extensive genome-wide association studies (GWAS) summary datasets, with a focus on identifying common immune cell traits with statistically significant causal associations between AP and sepsis.

Results

Our investigation identified 44 immune cell traits unidirectionally associated with AP and 36 traits unidirectionally associated with sepsis. Among these, CD127 on CD28+ CD45RA- CD8+ T cells emerged as a common mediator, accounting for 5.296% of the increased risk of sepsis in AP patients. This finding highlights the significant role of specific memory CD8+ T cells in the pathophysiology of AP and its progression to sepsis.

Conclusion

This study elucidates the critical role of specific immune cell traits, particularly CD127hi memory CD8+ T cells, in the progression of AP to sepsis. Our findings provide a foundation for future research into targeted immune-modulatory therapies, potentially improving patient outcomes in AP-related sepsis and offering new insights into the complex immunological dynamics of this condition.

Severe Pain in Chronic Pancreatitis Patients: Considering Mental Health and Associated Genetic Factors

Pain is the most distressing and disruptive feature of recurrent acute pancreatitis (RAP) and chronic pancreatitis (CP) resulting in low quality of life (QOL) and disabilities. There is no single, characteristic pain pattern in patients with RAP and CP. Abdominal imaging features of CP accurately reflect morphologic features but they do not correlate with pain. Pain is the major driver of poor quality of life (QOL) and it is the constant pain, rather than intermittent pain that drives poor QOL. Furthermore, the most severe constant pain experience in CP is also a complex condition. The ability to target the etiopathogenesis of severe pain requires new methods to detect the exact pain mechanisms in an individual at cellular, tissue, system and psychiatric levels. In patients with complex and severe disease, it is likely that multiple overlapping mechanisms are simultaneously driving pain, anxiety and depression. Quantitative sensory testing (QST) shows promise in detecting alterations in central processing of pain signals and to classify patients for mechanistic and therapeutic studies. New genetic research suggests that genetic loci for severe pain in CP overlap with genetic loci for depression and other psychiatric disorders, providing additional insights and therapeutic targets for individual patients with severe CP pain. Well-designed clinical trials that integrate clinical features, QST, genetics and psychological assessments with targeted treatment and assessment of responses are required for a quantum leap forward. A better understanding of the context and mechanisms contributing to severe pain experiences in individual patients is predicted to lead to better therapies and quality of life.

Constant-severe pain in chronic pancreatitis is associated with genetic loci for major depression in the NAPS2 cohort

BACKGROUND

Pain is the most debilitating symptom of recurrent acute pancreatitis (RAP) and chronic pancreatitis (CP) and often requires chronic opioids or total pancreatectomy with islet autotransplantation to manage. Pain is a complex experience that can be exacerbated by depression and vice versa. Our aim was to test the hypothesis that depression-associated genes are associated with a constant-severe pain experience in RAP/CP patients.

STUDY

A retrospective study was done using North American Pancreatitis Study II (NAPS2) genotyped RAP and CP patients with completed case report forms (n = 1,357). Subjects were divided based on pattern of pain and pain severity as constant-severe pain (n = 787) versus not constant-severe pain (n = 570) to conduct a nested genome-wide association study. The association between reported antidepressant medication use and depression gene loci was tested.

RESULTS

Constant-severe pain was reported in 58% (n = 787) of pancreatitis patients. No differences in sex or alcohol consumption were found based on pain severity. Antidepressant use was reported in 28% (n = 223), and they had lower SF-12 mental quality of life (MCS, p < 2.2 × 10^- 16). Fifteen loci associated with constant-severe pain (p < 0.00001) were found to be in or near depression-associated genes including ROBO2, CTNND2, SGCZ, CNTN5 and BAIAP2. Three of these genes respond to antidepressant use (SGCZ, ROBO2, and CTNND2).

CONCLUSION

Depression is a major co-factor in the pain experience. This genetic predisposition to depression may have utility in counseling patients and in instituting early antidepressant therapy for pain management of pancreatitis patients. Prospective randomized trials are warranted.

CLINICAL TRIALS REGISTRATION

Clinicaltriasl.gov.# NCT01545167.