Incidence, risk factors and outcomes of checkpoint inhibitor-induced liver injury: A 10-year real-world retrospective cohort study

Background & Aims

Checkpoint inhibitors (CPI) account for increasing numbers of drug-induced liver injury (DILI) cases. We aimed to determine the incidence rate and risk factors associated with checkpoint inhibitor-induced liver injury (ChILI).

Methods

Prescription event monitoring was performed on all melanoma and renal cancer patients who received CPI at a tertiary centre between 2011 and 2021. ChILI cases were identified using the definitions, grading, and causality assessment methods validated for DILI. We assessed risk factors associated with ChILI in CPI-naive patients using multivariable logistic regression model. Consecutive patients with suspected ChILI from two other tertiary centres were adjudicated and combined for case characterisation and outcomes of ChILI.

Results

Out of 432 patients who received CPI over 10 years, ChILI occurred in 38 (8.8%) with an overall incidence rate of 11.5 per 1,000 person-months (95% CI 8.2-15.8). Probability of ChILI was highest in combination therapy (32%) and no new events occurred beyond 135 days of treatment. Risk factor analysis showed that combination therapy, female sex, higher baseline alanine transferase level and lower baseline alkaline phosphatase level were independently associated with higher risk of ChILI. In total, 99 patients were adjudicated to have ChILI from three centres. Although Common Terminology Criteria for Adverse Events classified 20 patients (20.2%) to have 'life-threatening' grade 4 hepatitis, ChILI severity was graded as mild in 45 (45.5%) and moderate in the remaining 54 (54.5%) cases.

Conclusions

The real-world risk of ChILI is higher than previously reported. Among patients receiving dual CPI, this risk falls markedly after 4.5 months. As Common Terminology Criteria for Adverse Events overestimates its clinical severity, case-definition, evaluation and management of ChILI should be revised to harmonise care.

Impact and implications

Using prescription event monitoring over a 10-year period, the incidence rate of checkpoint inhibitor induced liver injury (ChILI) based on established case definitions for drug-induced liver injury (DILI) is 11.5 per 1,000 person-months. Formal causality assessment identified an alternative cause in 19% of patients with suspected ChILI highlighting the importance of systematic evaluation by clinicians to minimise unnecessary immunosuppression. Intensity of monitoring in patients receiving combination therapy regime after 4.5 months of therapy can be reduced as the risk of new onset ChILI beyond this point is minimal. Current Common Terminology Criteria for Adverse Events (CTCAE) grading overestimates clinical severity of ChILI and hence contributes to avoidable hospitalisation.

Aortic Slimgraft: ex vivo and in vivo study

In this article we describe a method for assembling an endovascular graft within the aorta with a graft and then a stent introduced sequentially over a guidewire as separate components. In the ex vivo study, an endovascular graft that was 25 mm in diameter was introduced through a 9F introducer. In the in vivo study, smaller endovascular grafts were placed in the aortas of four healthy pigs and five pigs with aortic aneurysms. Our data suggest that this very low profile system may have significant clinical implications because it converts aortic repair into a percutaneous procedure.

Intrathoracic lymphadenopathy in patients with empyema

PURPOSE

Our goal was to determine the prevalence of intrathoracic lymphadenopathy on chest CT in patients with empyema.

METHOD

We retrospectively identified 27 patients (14 men, 13 women, mean age 43 years) with nontuberculous empyema examined with chest CT. All scans were reviewed by two of three board-certified radiologists for the presence of intrathoracic lymphadenopathy (> or = 1 cm, short axis) in an American Thoracic Society (ATS) nodal station or the internal mammary region. Differences were resolved by consensus.

RESULTS

Thirteen (48%) patients with empyema had lymphadenopathy on chest CT. The mean number of enlarged lymph nodes for the patients with lymphadenopathy was 3.2 (SD +/-2.3, range 1-8). The mean size of the largest lymph node was 1.4 cm (range 1.0-2.5 cm). The lymphadenopathy was unilateral and ipsilateral to the empyema in seven (54%), bilateral in five (38%), and unilateral contralateral to the empyema in one. The distribution of lymphadenopathy according to ATS nodal stations was 4R (n = 8), 7 (n = 6), 10R (n = 5); n = 2 each 2R, 10L, 11L; and n = 1 each 11R, 2L, 4L, and 6. Four patients had internal mammary lymphadenopathy. Pleural fluid and smooth pleural thickening were present in each case. Four patients had follow-up CT after treatment. There was a decrease or resolution of the lymphadenopathy in each case.

CONCLUSION

Intrathoracic lymphadenopathy is a common CT finding in patients with empyema and occurred in 48% of this series. In patients with smooth pleural thickening and pleural effusion, intrathoracic lymphadenopathy should not be used as a criterion to differentiate empyema from malignant or tuberculous pleural effusion.