Affected children are susceptible to infection by Gram-positive and gram-negative bacteria and fungi, with Staphylococcus aureus being the most common infectious cause. Infections in CHS patients tend to be very serious and even life-threatening. Neuropathy often begins in the teenage years and becomes the most prominent problem. Few patients with this condition live to adulthood.Most children with Chédiak–Higashi syndrome ultimately reach a stage known as the "accelerated phase", or the "lymphoma-like syndrome", in which defective white blood cells divide uncontrollably and invade many of the bodys organs. The accelerated phase is associated with fever, episodes of abnormal bleeding, overwhelming infections, and organ failure. These medical problems are usually life-threatening in childhood. Causes
Mutations in the CHS1 gene (also called LYST) located on the chromosome 1q42-q43 have been found to be connected with Chédiak–Higashi syndrome. This gene provides instructions for making a protein known as the lysosomal trafficking regulator. Researchers believe that this protein plays a role in the transport (trafficking) of materials into lysosomes. Lysosomes act as recycling centers within cells. They use digestive enzymes to break down toxic substances, digest bacteria that invade the cell and recycle worn-out cell components. Although the lysosomal trafficking regulator protein is involved in the normal function of lysosomes, its exact role is unknown.In melanocytic cells, LYST gene expression may be regulated by MITF. Mutations in MITF are known to cause Waardenburg syndrome type 2 and Tietz syndrome, which result in depigmentation and deafness. Pathophysiology
CHS is a disease causing impaired bacteriolysis due to failure of phagolysosome formation.
Chronic bronchitis
Chronic bronchitis is a lower respiratory tract disease, defined by a productive cough that lasts for three months or more per year for at least two years. The cough is sometimes referred to as a smokers cough since it often results from smoking. When chronic bronchitis occurs together with decreased airflow it is known as chronic obstructive pulmonary disease (COPD). Many people with chronic bronchitis have COPD however, most people with COPD do not also have chronic bronchitis. Estimates of the number of people with COPD who have chronic bronchitis are 7 to 40%. Estimates of the number of people who smoke and have chronic bronchitis who also have COPD is 60%.The term "chronic bronchitis" was used in previous definitions of COPD but is no longer included in the definition. The term is still used clinically. While both chronic bronchitis and emphysema are often associated with COPD, neither is needed to make the diagnosis. A Chinese consensus commented on symptomatic types of COPD that include chronic bronchitis with frequent exacerbations.Chronic bronchitis is marked by mucus hypersecretion and mucins. The excess mucus is produced by an increased number of goblet cells, and enlarged submucosal glands in response to long-term irritation. The mucous glands in the submucosa secrete more than the goblet cells. Mucins thicken mucus, and their concentration  has been found to be high in cases of chronic bronchitis, and also to correlate with the severity of the disease.