Clinically significant respiratory disease that requires mechanical ventilation support or % oxygen. Requiring mechanical ventilation Subjects requiring vasopressor or mechanical ventilation. Pulmonary failure (requiring mechanical ventilation) not due to active LCH. Adequate respiratory function defined as not requiring supplemental oxygen or mechanical ventilation; oxygen saturation % or higher on room air RETREATMENT WITH MODIFIED T-CELLS EXCLUSION CRITERIA: Patient requiring supplemental oxygen or mechanical ventilation Adequate respiratory function defined as not requiring supplemental oxygen or mechanical ventilation; oxygen saturation % or higher on room air Adequate respiratory function defined as not requiring supplemental oxygen or mechanical ventilation; oxygen saturation % or higher on room air Adequate respiratory function defined as not requiring supplemental oxygen or mechanical ventilation; oxygen saturation % or higher on room air Subject does not require supplemental oxygen or mechanical ventilation, and oxygen saturation by pulse oximetry is % or higher on room air. Require mechanical ventilation or vasopressors for hemodynamic support at the time of randomization. Not requiring supplemental oxygen or mechanical ventilation; oxygen saturation % or higher on room air; no dyspnea at rest ELIGIBILITY CRITERIA FOR T-CELL PRODUCT INFUSION: Not requiring supplemental oxygen or mechanical ventilation, oxygen saturation % or higher on room air and no dyspnea at rest RETREATMENT WITH MODIFIED T CELLS: Patient requiring supplemental oxygen or mechanical ventilation Endotracheal intubation and mechanical ventilation at any FiO ELIGIBILITY CRITERIA TO UNDERGO OPTIONAL T CELL ABLATION\r\n* Research participant has >= % CAR T cells in the peripheral blood\r\n* Pulmonary: not requiring supplemental oxygen or mechanical ventilation, oxygen saturation % or higher on room air\r\n* Cardiovascular: not requiring pressor support, no symptomatic cardiac arrhythmias, no acute coronary syndrome, or uncontrolled hypertension\r\n* Renal Function: serum creatinine did NOT increase by more than . fold from baseline (at time of screening)\r\n* Liver Function: adequate liver function defined as total bilirubin =< . mg/dl \r\n* AST =< x ULN, ALT =< x ULN\r\n* Neurological: research participant without clinically significant encephalopathy/new focal deficits\r\n* Infectious diseases: no clinical evidence of uncontrolled active infectious process Not requiring supplemental oxygen or mechanical ventilation, oxygen saturation % or higher on room air (ELIGIBILITY CRITERIA AT TIME OF INFUSION OF GENETICALLY MODIFIED AUTOLOGOUS T CELLS): Not requiring supplemental oxygen or mechanical ventilation, oxygen saturation % or higher on room air Not requiring supplemental oxygen or mechanical ventilation, oxygen saturation % or higher on room air Pulmonary: not requiring supplemental oxygen or mechanical ventilation, oxygen saturation % or higher on room air Pulmonary criteria: not requiring supplemental oxygen or mechanical ventilation, oxygen saturation % or higher on room air Require mechanical ventilation or vasopressors for hemodynamic support at the time of enrollment. Clinically significant respiratory disease that requires mechanical ventilation support or % oxygen. Patients on mechanical ventilation. Not requiring supplemental oxygen or mechanical ventilation, oxygen saturation % or higher on room air Mechanical ventilation, renal replacement therapy, admitted in intensive care until at time of enrollment Has been on mechanical ventilation for > days Currently on invasive mechanical ventilation or noninvasive positive pressure ventilation (CPAP or bilevel positive airway pressure) or requiring > LPM supplemental oxygen therapy to maintain O saturation > % due to hypoxemia Oxygenation index (OI) > , but < , for two consecutive blood gases which should be separated by at least one hour within hours of the initiation of mechanical ventilation. In the critical care unit, or use of mechanical ventilation or use of renal replacement therapy at any time post HCT and prior to administration of ibrutinib Respiratory failure requiring mechanical ventilation or non-invasive ventilation Requiring mechanical ventilation Requires mechanical ventilation or is hemodynamically unstable at the time of randomization Respiratory failure requiring greater than Lpm supplemental oxygen (O) by nasal cannula or mechanical ventilation within the past six weeks