Background:

- This research is being done to describe the types of bacteria found in the mouths of patients who have severe aplastic anemia (SAA) and are treated with drugs that suppress the immune system or with stem cell transplant. People with SAA who receive these treatments are more likely to get infections. Studies show that there might be a link between the bacteria in your mouth and those bacteria that can cause infections. The bacteria found in the mouths of patients with SAA will be described.

Objectives:

- To understand the changes in mouth bacteria that are related to treatment and to describe the oral bacterial environment.

Eligibility:

• Adults at least 18 years of age who are going to be treated for SAA.
• Healthy volunteers at least 18 years of age.

Design:

• Participants will answer questions about their medical history and dental care. Their mouths will be examined.
• Participants with SAA will be tested during treatment for their disease, over the course of 1 year. All participants with SAA will be tested at 3 scheduled appointments. Any participants who require a breathing tube will receive additional tests.
• Healthy volunteers will be tested during 1 visit.
• Participants will give two samples each time. A saliva sample will be taken with a disposable padded tool. Skin cells will be collected from the tongue with a small plastic brush.

The mouth is a complex biological ecosystem normally containing over 700 different species of bacteria. Some of these bacteria live in an exopolysacchride matrix biofilm and occupy specific niches in this complex oral environment. Understanding the oral environment and the microbiota that inhabit it will assist in determining their impact on health and disease. There are several studies in critically ill patients demonstrating changes in oral bacteria related to acute illness. Identification of respiratory pathogens in the mouth has led researchers to hypothesize that a relationship exists between the oral cavity and pulmonary infections. This descriptive study will characterize the oral microbiota of patients who have severe aplastic anemia (SAA). Patients will be followed for 1 year after treatment for development of respiratory symptoms that require intubation. A difference in the oral microbiome will be identified in specimens collected before and after treatment.

• All adult patients who are scheduled to receive treatment for SAA will be screened for this protocol. These patients will be recruited from the numerous protocols that are actively accepting new research participants at the Clinical Center, NIH.

INCLUSION CRITERIA

Any adult patient (greater than or equal to18 years of age), diagnosed with SAA.

EXCLUSION CRITERIA

Any SAA patient found to have significant tooth loss from decay or is edentulous are excluded. This exclusion criteria will be assessed by the PI or her representative prior to signing the informed consent.