Acid-fast stain test
A laboratory test that may be used to determine whether or not mycobacteria are present microscopically in tissue, bronchoscopy, or sputum samples. The acid-fast stain does not identify specific types of mycobacteria.

AFB
Acid fast bacilli (Mycobacteria are AFB).

ATS
American Thoracic Society. This group is responsible for developing diagnosis and treatment guidelines for nontuberculous mycobacteria (NTM) including MAC.

Bronchiectasis
A chronic lung disease characterized by permanent, irreversible progressive, abnormal dilation and destruction of the bronchi that results in poor clearance and pooling of mucus. This disorder also makes a person more susceptible to infections caused by bacteria such as Pseudomonas aeruginosa as well as nontuberculous mycobacteria (NTM) including MAC and Mycobacterium abscessus.

Bronchoscopy
Involves putting a tube down into the lungs to obtain specimens for culture or to perform a biopsy of the lung. This procedure may be necessary in cases where the patient is unable to cough up samples.

CD4 cells
Also known as T4 cells or T-helper cells. A specialized subgroup of T-lymphocytes that helps the body fight invading organisms. These helper cells are a crucial component of the immune system because they coordinate the activities of other cells involved in resisting or controlling infection.

COPD
Chronic obstructive pulmonary disease.

Cultures
Refers to the growth of microorganisms under laboratory conditions. When a person is tested for infection, organisms found in blood, sputum, or tissue samples are grown in the laboratory in order to be analyzed and identified.

Cystic Fibrosis (CF)
A hereditary disease associated with abnormal mucus production. Patients develop bronchiectasis, and some adolescents also develop NTM infections, including MAC.

Disseminated infection
An infection that is widely spread throughout the body, not contained in a single location. Disseminated MAC is seen almost exclusively in advanced HIV disease (AIDS).

Dyspnea
Shortness of breath.

Expectorate
Cough up sputum or phlegm.

FDA
Food and Drug Administration. This agency approves the use of medicines or medical aids in the U.S.A.

Fluorochrome stain
Fluorescent stain for AFB that allows visualization of the MAC organism directly in the sputum.

Hemoptysis
Coughing up of blood.

HRCT
High resolution computed tomography. A highly sensitive and specific technique specific for diagnosis of bronchiectasis and seeing the nodules of MAC infection.

Immune system
A combination of cells and proteins that work together in the body to fight foreign substances, including microorganisms such as bacteria and viruses.

Intermittent therapy
Treatment for MAC given 3 times weekly (usually Monday, Wednesday, Friday).

Kilogram (kg)
1 kg = 2.2 lbs.

LFTs
Liver function tests including measurement of blood levels of bilirubin (a by-product of red blood cell metabolism), and liver cell enzymes that include alkaline phosphatase (alk phos), gamma glutamyl transpeptidase (GGT), alanine aminotransferase (ALT or SGPT), and aspartate aminotransferase (AST or SGOT). These are monitored in patients taking MAC medicines by taking a small blood sample, especially over the first six months.

MAC
Mycobacterium avium complex

Macrophage
A type of white blood cell that lives in the tissues (especially the lung) that protects the body from infection by destroying bacteria and other foreign substances.

MAI
Mycobacterium avium-intracellulare. Same as Mycobacterium avium complex or MAC.

Monotherapy
Treatment with one drug.

Opportunistic
Pertaining to organisms such as viruses and bacteria that are common in nature and do not cause disease ordinarily, but that can cause serious illness in a person who has a weakened immune system. The infections they cause are also called opportunistic infections.

Placebo
A pill containing an inactive, harmless material (usually sugar) that is temporarily substituted for a medication in some people during drug evaluation studies so patients will not know if they are receiving the test drug or not.

Polymicrobial
Involving multiple species of organisms.

Pulmonary Function Tests (PFTs)
Involves blowing into a tube to determine the strength of your lungs. Allows one to quantitate damage done to your lung by infections such as MAC or bronchiectasis or smoking.

Regimen
Planned course of treatment.

Sputum
Phlegm; material that is coughed from the lungs, bronchi, and trachea through the mouth.

Sputum conversion
Three consecutive negative AFB cultures on drug therapy after being culture positive.

Tinnitus
Ringing in the ears. Sounds like roaring of the ocean, bells, or crickets – common toxicity with streptomycin or amikacin therapy.

Wasting syndrome
Severe weakness and weight loss.