Management of immune-related adverse events resulting from immune checkpoint blockade

Introduction: Immune checkpoint inhibitors (ICI) are now a standard of care in the treatment of many cancers leading to durable responses in patients with metastatic disease. These agents are generally well tolerated but may lead to the occurrence of immune-related adverse events (irAEs). As any organ may be affected, clinicians should be aware of the broad range of clinical manifestations and symptoms and keep in mind that toxicities may occur late, at any point along a patient’s treatment course. Although the most common irAEs are rarely severe, some of them may be associated with great morbidity and even become life-threatening. The rate of occurrence, type and severity of irAEs may vary with the type of ICI; thus, grade 3 and 4 irAEs are reported in more than 55% of patients treated with the combination of ipilimumab 3 mg/kg and nivolumab 1 mg/kg.

Area covered: This review presents the management of irAEs resulting from checkpoint blockade, with a focus on rare irAEs.

Expert commentary: With the development of immuno-oncology and the expanding role of ICI, physicians have learnt to diagnose and treat most of the irAEs that can occur. This review provides an overview of current guidelines, previously published studies and our multidisciplinary team based practices.     

Complications occurring during conservative management of splenic trauma in children.

AIM: Conservative management of splenic rupture in haemodynamically stable children is now generally accepted. However, during follow-up, many complications can occur. The aim of this study was to describe the complications we observed and to propose a standardised follow-up adapted to them. METHODS: Between March 1992 and December 2002 we managed 65 children (aged between 3 and 15 years old) with accidental splenic rupture. Follow-up and treatment consisted of a 10-day bed rest with sonogram and Doppler controls on the 5th and 10th day and subsequently every month until complete healing. Complications included secondary haemorrhage in 3 cases, cystic evolution in 5 cases, and pseudo-aneurysm in 2 cases. All were treated by renewed bed rest. Three of the cysts resolved spontaneously, the other two underwent cystic resection and epiploplasty by laparotomy (n = 1) or laparoscopy (n = 1) and both pseudo-aneurysms were selectively embolised. There were no splenectomies. CONCLUSIONS: Complications essentially occurred in older children and were not related to gender, type of fracture, or extent of bleeding. Cystic evolution of the sub-capsular haematomas can appear up to 1 month after trauma. Peripheral pseudo-aneurysms which could be responsible for secondary haemorrhages were selectively embolised. We favour the use of the Doppler sonogram for follow-up until total recovery of these patients, even in low-grade traumas. Considering the number of complications encountered we do not believe the American evidence-based guidelines are suitable for our population.     

Amygdaloid control over interspecies and shock-induced aggression in the rat (author's transl)]

The effect of lateral amygdala or stria terminalis lesions on two different kinds of aggressive behavior have been studied in the rat. The lateral amygdala lesion does not change the non-killing rat's behavior towards mice; but it markedly reduces the shock-induced intraspecific aggression, without changing the flinch and jump thresholds to the electric shocks. A bilateral interruption of the stria terminalis elicits aggressive reactions in previously non killing rats. This initiation of mouse killing behavior is clearly facilitated through a prior food deprivation for 3 days. The interruption of the stria terminalis changes neither the shock induced aggression, nor the response thresholds. As the stria is the main efferent pathway of the cortico-medial nuclei of the amygdala, these results are in accordance with previous conclusions that tentatively localized in this part of the amygdala an essential component of a mechanism which inhibits muricide behavior in the non killing rat, probably through interactions with the olfactory input. This system is largely independent of amygdaloid structures which facilitate shock-induced intraspecific aggression.     

Initiation of mouse-killing behavior following amygdaloid lesions in the rat(author's transl)]

Long-Evans hooded rats were tested for emotionality and observed by pairs in an open field for 6 consecutive days. Postoperative observations indicated that both emotionality and social cohesiveness were dramatically altered by ventromedial and anterolateral hypothalamic lesions. Tegmental, interpeduncular and habenular lesions were shown to have no effect on these behaviors. Alterations in behavior observed following hypothalamic ablations were related to septal and amygdaloid effects, and the possibility of separate projection systems for emotionality and social cohesiveness was discussed.     

Dorsal tegmentum kindling in rats.

Electrical stimulations were applied daily for 40 days to the dorsal tegmentum in 9 rats through chronically implanted bipolar electrodes. The intensity of current (2 s trains of 50 Hz, 1 ms monophasic square waves) necessary to trigger a full tonic seizure was determined and applied for all further stimulations. Initial stimulations induced a tonic seizure with a low voltage fast electrocorticographic activity. After repeated stimulations, high amplitude spike and wave discharges developed over the cortex, their duration exceeding 50 s at the 40th stimulation. Simultaneously, the tonic seizures evolved into tonic-clonic fits with bilateral myoclonias following the tonic phase. These EEG and behavioral modifications persisted for 30 days after the last stimulus. These results demonstrate that kindling may be obtained from brainstem structures.     

Optimization of an elispot assay to detect cytomegalovirus-specific CD8+ T lymphocytes

Various arguments suggest that CD8+ T lymphocytes play a major role in the control of cytomegalovirus (CMV) infection. The detection of CMV-specific CD8+ T cells may therefore provide additional information about CMV virus detection to predict the risk of development of CMV disease, especially in immunodepressed transplant recipients. We compared and tested various experimental conditions to optimize an enzyme-linked immunospot assay (Elispot) assay for the detection of CMV-specific CD8+ T lymphocytes. The indirect Elispot assay with one six-day in vitro sensitization step was found to be the most sensitive method to detect CMV-specific CD8+ T cells compared to direct Elispot with unfractionated peripheral blood mononuclear cells or purified CD8+ T cells. We showed that low doses of interleukin-2 during the in vitro culture enhanced the sensitivity of this test, and tetramer staining was performed to verify the high efficiency of this in vitro stimulation step. We directly loaded the specific CMV peptide during the Elispot assay and demonstrated that the use of T2 cells did not improve its sensitivity. Elispot for the detection of interferon-gamma appears to be more sensitive and reliable than measurement of tumor necrosis factor alpha or granzyme B. This technique was successfully applied to detect CMV-specific CD8+ T cells in human leukocyte antigen A2 (HLA-A2) and HLA-B7 healthy patients and in one lymphopenic post-transplant patient with positive CMV serology. This highly sensitive test may be a useful tool to assess T-cell immunity directed against CMV in immunodepressed patients.