CCR2 and hypersensitivity pneumonitis: We found that at all stages of pulmonary sarcoidosis including those with or without alveolitis and those on or off immunosuppressive therapy main cellular sources of CCR1, CCR2, and CCR3 were epithelioid histiocytes, multinucleated giant cells and other infiltrating mononuclear cells that formed the non-necrotizing granulomas (Figure 5).