The important influence of gender in non-tuberculous mycobacterial infections, also referred to as MAC, is reflected in the name that has been given to this disorder: "Lady Windermere's Syndrome." In 1992 two physicians published a medical article describing six older women with infection of their lungs by the germ, Mycobacterium avium. These were otherwise healthy women who developed a chronic infection involving the middle portions of their lungs by a germ that was thought rarely to cause infection in persons with normal immune systems.
The authors of this article thought that the reason for this unusual infection had partly to do with bronchial anatomy (making it harder to clear secretions from these parts of the lungs) and partly with the genteel behavior of these women, whose "proper manners" made them less likely to cough and expectorate mucus from their lungs. They coined the expression, "Lady Windermere's Syndrome," naming it after a character in an Oscar Wilde play (Lady Windermere's Fan) whose Victorian-era manners prevented her from coughing and spitting.
These physicians were probably totally wrong about why some people are prone to developing persistent lung infection with this family of germs, the mycobacteria, but the observation was correct that it is more common in women than in men. Curiously, it is particularly common in middle-aged and older women of thin body type. No one knows why there is this unusual susceptibility, but many believe that it has more to do with the immune system than manners! For instance, speculation has focused on reduced production of the germ-fighting protein, interferon-gamma, leading to an increased vulnerability to this germ.
The most common of these non-tuberculous mycobacterial infections is Mycobacterium avium-intracellulare, also called Mycobacterium avium complex. Hence the abbreviations, MAI or MAC. Although tuberculosis, or TB, is also a mycobacterial infection, these infections are not a form of tuberculosis, and importantly, they are not contagious in the way that tuberculosis is. They can infect persons with pre-existing lung conditions, such as emphysema or bronchiectasis, but most often they occur in otherwise healthy people, especially women.
Non-tuberculous mycobacterial infections are slow-growing infections that can cause cough and phlegm, weight loss, fevers, coughing of blood, shortness of breath, and chest pains. Treatment, when needed, is often difficult, requiring multiple medications for many months. Management of non-tuberculous mycobacterial infection truly "takes a village," a team that often includes a pulmonary specialist, infectious disease specialist, nutritionist, and social worker. Our team at Brigham and Women's Hospital includes Drs. Manuela Cernadas and Christopher Fanta (Pulmonary Medicine), with collaborations in multiple other disciplines, as needed.
Mycobacterial germs can cause injury to the bronchial tubes, leaving the walls weakened and bowed out ("-ectatic"), without the normal defense mechanisms, including loss of the hair-like structures (cilia) that sweep mucus out of the lungs. These dilated bronchial tubes become pockets where germs and mucus can accumulate, leading to chronic infection and often to a daily cough with thick, discolored sputum production. This condition is called bronchiectasis (bronk'-ee-eck"-ta-sis).
There are many causes of bronchiectasis, including inherited conditions such as cystic fibrosis, immotile cilia syndrome, and alpha-1 antitrypsin deficiency. Other patients acquire a condition of impaired immune defenses leading to bronchial infection and bronchiectasis, such as hypogammaglobulinemia or rheumatoid arthritis.
Because bronchiectasis is both a chronic infection and a disease of the bronchial tubes, it makes sense that care is often provided via collaboration between an infectious disease expert and an pulmonologist. Gender-sensitive care for bronchiectasis is available at WoRLD, utilizing the immense resources in Infectious Diseases and Pulmonary Medicine at Brigham and Women's Hospital.