An observational study in Rhinosinusitis, sponsored by University of Alabama at Birmingham. Recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-03-17.
Sponsored by University of Alabama at Birmingham · Observational
The purpose of this study is to determine if acquired (partial) Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) deficiency contributes substantially to the pathogenic mechanisms underlying Chronic Rhinosinusitis (CRS), creating a localized environment that impairs mucociliary clearance (MCC).
Nasal Potential Difference (NPD) measurements will be conducted on participants. The NPD measurement, is a bioelectric assay of CFTR-dependent ion transport that has been used in a variety of protocols designed to detect CFTR function. A 4-Step protocol will be utilized. The nasal cavities will be perfused in a step-wise fashion with the following solutions: 1) Ringer's solution, 2) Ringer's solution + amiloride 100μM, 3) Low-Cl--containing solution, and 4) Low-Cl- + isoproterenol (10 µM). The potential difference will be monitored in nasal epithelium in comparison to an agar filled reference butterfly electrode placed in the volar aspect of the forearm, and connected via a calomel cell to a high impedance voltmeter.
Following placement of the subcutaneous reference bridge, the nasal probe will be secured 1-3 cm within the inferior meatus and secured in position at the most polarizing position. Each nare will then be sequentially perfused with Ringer solution. All nasal potential difference tracings will be scored independently by a single reviewer.
The investigator and an internal committee comprised of Gregory Fleming James Associate Scientists will oversee the safety of the study. Our internal committee is a multidisciplinary group consisting of physician and subspecialists who, collectively, have experience in treatment patients with cystic fibrosis and other airway disease in the conduct of randomized clinical trials. The primary responsibility of this committee is to protect the safety and welfare of subjects consenting to the investigator's procurement of remnant tissue during endoscopic sinus procedure. Members are responsible for reviewing procedural conduct, including acquisition of consents and materials, to protect patient well-being. An interim data safety review will be conducted on a yearly basis. The committee will consist of at least 3 members with clinical trials experience in airway diseases. During annual review, issues relating to the safety and process for acquiring human tissues will be reviewed. Summary reports from each annual meeting will be prepared and will address concerns about the procurement of tissue or any other information deemed pertinent to the review.
251 studies on the registry are indexed under Rhinosinusitis; 69 are open to participants now.
This study's planned enrollment of 20 is below the median of 120 across 61 observational studies indexed under Rhinosinusitis.
Browse Rhinosinusitis studies →University of Alabama at Birmingham is the lead sponsor of 1,421 studies on the registry; 277 are open to participants now.
Of its 164 completed or terminated interventional studies of FDA-regulated products, 130 (79%) have results posted.
Counted across the registry records on this site, refreshed daily.
Patients presenting to UAB for evaluation of CRS
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
The patient eligibility criteria are designed to limit enrollment to healthy individuals and patients who clearly have CRS based on Sinus and Allergy health partnership criteria, but who are sufficiently well (both in terms of CRS and in terms of concomitant illness, such as asthma) to safely participate in study procedures and provide interpretable results.
Inclusion Criteria:
a. Patients with CRS will be diagnosed according to Sinus and Allergy Health Partnership symptom-based and objective criteria as follows: i. Duration of disease is qualified by continuous symptoms (≥ 2 major factors or at least 1 major factor \& 2 minor symptoms; Table 2) for ≥ 12 consecutive weeks or ≥ 12 weeks of physical findings. ii. One of these signs of inflammation must be present and identified in association with ongoing symptoms.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Measurable Difference in CFTR function
A \>-5 mV increase in total chloride secretion (change in NPD following nominal Cl- solution + amiloride + isoproterenol) is typically designated as evidence of measurable difference in CFTR function. Results of NPD measurements between CRS patients and healthy controls will be examined.
Time frame: One Year
Started Jan 2015 (actual). Primary completion is estimated for Dec 2026, 143 months after the start.
Of 22 observational studies under Rhinosinusitis, half reached primary completion within 27 months of starting (the median), counting those still running; a quarter within 15 and three quarters within 71. This study's planned 143 months is above that.
How these figures are worked out, and which studies are left out of them.
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University of Alabama at Birmingham →