I. Clinical manifestations Chronic graft-versus-host disease is a multisystemic disease affecting almost all tissues and organs with diverse clinical manifestations and features similar to those of autoimmune and other immune diseases, such as: scleroderma, dry syndrome, primary biliary cirrhosis, wasting disease, occlusive fine bronchitis, immune hemocytopenia, and chronic immunodeficiency. The tissues and organs most commonly involved in cGVHD include: skin, oral cavity, eye, liver, lung, gastrointestinal tract, hematopoietic and immune system. 1. The skin may show lichenoid changes (erythema, papules), deep sclerotic features (thick, hard, taut skin), skin heterochromatosis (hyperpigmentation or hypopigmentation), sweat gland damage, and poor skin regulation to temperature changes. The mouth is dry, white film, ulcers. Eyes may exhibit dryness, photophobia, Schimer test ≤ 5mm/5min, plus symptoms of one other organ. 2. The liver shows cholestasis with elevated bilirubin, glutamic aminotransferase, glutamic aminotransferase, and alkaline phosphatase. 3, lung cGVHD clinical symptoms include cough, mostly dry, dyspnea, rare manifestations include pneumothorax, mediastinal emphysema, subcutaneous emphysema. Blood gas analysis: hypoxemia, pulmonary function tests: obstructive or restrictive ventilation dysfunction. HRCT: hairy glass-like changes, lamellar and nodular shadow, bronchial dilatation and other manifestations. Scattered expiratory croup and diffuse inspiratory bursts can be heard on lung auscultation. There are also other organ cGVHD manifestations. 4. Gastrointestinal cGVHD manifests as anorexia, nausea, vomiting, diarrhea, and weight loss. The wasting syndrome may be a manifestation of cGVHD. Endoscopic examination reveals mucosal edema, erythema or local erosion. 5. The musculoskeletal system mainly presents with damaged fascia, joint stiffness or periarticular contracture, and limited movement of the extremities. Myositis with tenderness and elevated muscle enzymes may also be seen. Arthralgia and arthritis are rare. 6. Abnormal hematopoietic system with reduced blood cells, such as thrombocytopenia. Autoimmune hemolytic anemia. 7. Other rare manifestations are: plagiocele, pericardial or pleural effusion, peripheral nerve disease, myasthenia gravis, nephrotic syndrome, and cardiac involvement. II. Classification According to the damaged organs and scope, it is divided into limited type and extensive type. 1. limited cGVHD: 1 or both of the following: (1) limited skin lesions; (2) liver function abnormalities due to cGVHD 2. extensive cGVHD: either of the following: (1) extensive skin lesions; (2) limited skin lesions and/or liver function abnormalities due to cGVHD; plus either of the following: (1) liver biopsy showing chronic progressive hepatitis, pontine necrosis or cirrhosis; (2) Schirmer test for ocular involvement