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Frequently Asked Questions

1. Will the ME/CFS patients satisfy the Canadian Consensus criteria?

Yes, all patients will meet the Canadian Consensus criteria. All patients will be objectively tested for post-exertional malaise (PEM). Additionally, patients will be screened with validated functional scales to ensure that only patients with significant severity of symptoms are enrolled in the study.

2. Why is the focus of the study on only post-infectious ME/CFS patients?

This cohort has a clear, acute precipitating factor of their ME/CFS and would represent a uniform group of patients. The current study will conduct very extensive neuro/immune/microbial studies on an inpatient basis over several days to help identify a select number of parameters that could then be used to conduct a longitudinal study in a larger cohort with patients who have ME/CFS.

3. Why have recovered post-Lyme patients been included as controls?

Since we have focused on the PI-ME/CFS cohort, it would be useful to compare them against a cohort that also had an infection but then fully recovered. Many Lyme patients have already been evaluated at NIH.

4. Will there be additional control group?

There are many other potential control groups that can strengthen the science of the study through comparison. There is ongoing discussion about whether an additional control group or control groups should be included.

5. Why is the duration from onset for the PI-ME/CFS patients limited to 5 years?

It appears that some of the immune parameters and clinical manifestations may be duration-dependent. Hence, at this time, we are including patients who have had ME/CFS for greater than 6 months and less than 5 years. While it is our hope that we will recruit a homogeneous group, the extensive neuroimmune studies will allow us to look for duration-dependent parameters within this time range.

6. Will ME/CFS experts be involved in selecting patients to enroll?

Clinical experts will be reviewing the selection of patients at three different times in the enrollment process. Most patients will be recruited from well-established ME/CFS clinics that are being supported by the CDC in the Multi-site Clinical Assessment of CFS study ( Diagnostic validity will be reviewed as well by an executive committee, which include experts such as Dr. Elizabeth Unger from the CDC and Dr. W. Ian Lipkin from Columbia University. A final assessment of diagnostic validity will be performed by a team of clinical experts at NIH, including Drs. Fred Gill, Leorey Saligan, and Brian Walitt.

Follow these links for further information about the individuals mentioned:
Dr. Elizabeth Unger (
Dr. W. Ian Lipkin (
Dr. Fred Gill (
Dr. Leorey Saligan (
Dr. Brian Walitt (

7. When will the study start enrolling patients?

We anticipate that patients will start enrolling in the summer of 2016.

8. What is the role of the Lead Associate Investigator in the study?

The Lead Associate Investigator (LAI) will be assisting Dr. Nath with the oversight of the day to day clinical operations of the protocol. The LAI will work with the CDC and the NIH ME/CFS executive committee to coordinate screening of potential participants for the study. He will ensure that participants are provided with clear details of the research study prior to enrollment and that the informed consent process meets NIH standards. He will coordinate care with the local medical providers for participants. He will help integrate the work of all of the multidisciplinary experts who are collaborating in this complex undertaking and to provide clinical oversight for the study participants during their testing and work-up at the NIH Clinical center.

9. Will there be changes made to the current protocol?

The protocol is a process in evolution. Currently we are soliciting comments from the community and accordingly making amendments to the protocol. Our plan is to initially start the study by recruiting healthy volunteers to help us refine the study test procedures before we enroll the first patients with PI-ME/CFS. All changes to the protocol require approval from the Institutional Review Board (IRB).

10. When will more information be made available?

We plan to periodically update this website to provide information about this research study to the public. When the research protocol and informed consent forms are finalized and approved by the IRB, they will be made publically available.