Chimeric antigen receptor T (CAR-T) cell therapy is a new pillar in cancer therapeutics; however, its application is limited by the associated toxicities. These include cytokine release syndrome (CRS) and neurotoxicity. Although the IL-6R antagonist tocilizumab is approved for treatment of CRS, there is no approved treatment of neurotoxicity associated with CD19-targeted CAR-T (CART19) cell therapy. Recent data suggest that monocytes and macrophages contribute to the development of CRS and neurotoxicity after CAR-T cell therapy. Therefore, we investigated neutralizing granulocyte-macrophage colony-stimulating factor (GM-CSF) as a potential strategy to manage CART19 cell–associated toxicities. In this study, we show that GM-CSF neutralization with lenzilumab does not inhibit CART19 cell function in vitro or in vivo. Moreover, CART19 cell proliferation was enhanced and durable control of leukemic disease was maintained better in patient-derived xenografts after GM-CSF neutralization with lenzilumab. In a patient acute lymphoblastic leukemia xenograft model of CRS and neuroinflammation (NI), GM-CSF neutralization resulted in a reduction of myeloid and T cell infiltration in the central nervous system and a significant reduction in NI and prevention of CRS. Finally, we generated GM-CSF–deficient CART19 cells through CRISPR/Cas9 disruption of GM-CSF during CAR-T cell manufacturing. These GM-CSFk/o CAR-T cells maintained normal functions and had enhanced antitumor activity in vivo, as well as improved overall survival, compared with CART19 cells. Together, these studies illuminate a novel approach to abrogate NI and CRS through GM-CSF neutralization, which may potentially enhance CAR-T cell function. Phase 2 studies with lenzilumab in combination with CART19 cell therapy are planned.

Sulfur mustard is an alkylating agent that reacts with ocular, respiratory, cutaneous, and bone marrow tissues, resulting in early and late toxic effects. We compare these effects based on the experience in Iranian veterans exposed to the agent during the Iran-Iraq conflict . The first clinical manifestations of sulfur mustard poisoning occurred in the eyes with a sensation of grittiness, lacrimation, photophobia, blepharospasm, and corneal ulceration. Respiratory effects appeared as rhinorhea, laryngitis, tracheobronchitis, and dyspnoea. Skin lesions varied from erythema to bullous necrotization. Initial leukocytosis and lymphopenia returned to normal within four weeks in recovered patients, but marked cytopenia with bone marrow failure occurred in fatal cases. Late toxic effects of sulfur mustard were most commonly found in lungs, skin and eyes. Main respiratory complications were chronic obstructive pulmonary disease, bronchiectasis, asthma, large airway narrowing, and pulmonary fibrosis. Late skin lesions were hyperpigmentation, dry skin, atrophy, and hypopigmentation. Fifteen of the severely intoxicated patients were diagnosed with delayed keratitis, having corneal vascularization, thinning, and epithelial defect. Respiratory complications exacerbated over time, while cutaneous and ocular lesions decreased or remained constant. Both the severity and frequency of bronchiectatic lesions increased during long-term follow-up. The only deteriorating cutaneous complication was dry skin. The maximum incidence of delayed kaeratitis was observed 15 to 20 years after initial exposure. Being suggested as the main cause ofassociated with malignancies and recurrent infections, natural killer cells were significantly lower 16 to 20 years after intoxication.

Sulphur mustard (SM) is regarded as one of the most important agents of chemical warfare because of its simple and cheap chemical synthesis that makes it readily available for both terrorist and military use. SM acts as an alkylating agent that induces disruption of nucleic acids and proteins, impairing cell homeostasis and eventually causing cell death. It rapidly reacts with ocular, respiratory and cutaneous tissues, as well as bone marrow and the mucosal cells of the gastrointestinal tract, resulting in several devastating long-term effects on human health, many of which are not clinically or pathologically well defined. In light of the possible threat of SM use against military and civilian populations, physicians should be aware of its grave effects and knowledgeable how to care for its victims. The pattern of immediate and long-term toxic effects following exposure to SM is reviewed in this article with special references to the recent data available from over 100,000 chemical casualties incurred during the Iran-Iraq conflict.