The goal of this observational study is to learn about loin pain in people with Immunoglobulin A nephropathy (IgAN). The main question it aims to answer is: What changes occur in the kidneys, urine, and blood when people with IgAN experience loin pain? Participants will have MRI scans of their kidneys, provide urine and blood samples, and have their latest kidney function test results reviewed. For participants who experience loin pain, these assessments will be carried out during a pain episode and again when they are pain-free, so the results can be compared.
Some people with Immunoglobulin A nephropathy (IgAN) experience loin pain, or pain around the kidneys, but the underlying cause of this pain is not well understood. Current treatment options often do not provide effective pain relief, and a better understanding of the mechanisms involved may support the development of more targeted treatments in the future and help understand what this pain may mean for the disease state. This observational study will investigate whether loin pain in IgAN is associated with changes in the kidneys, kidney function, and biological markers in blood and urine. Participants will undergo magnetic resonance imaging (MRI) of the kidneys to assess whether there are structural or tissue-related differences during episodes of pain compared with pain-free periods. The study will also assess the renal pelvis, the urine-collecting part of the kidney, to explore whether it may be involved in the development of pain. Blood and urine samples will be collected to investigate whether biological molecules differ during pain episodes and pain-free periods. Urine samples will also be examined under the microscope to assess for the presence of blood cells or other features that may suggest kidney injury or inflammation. Participants' most recent kidney function test results will also be reviewed to explore whether kidney function is associated with the presence or severity of loin pain. Together, these assessments aim to provide a better understanding of what happens in the kidneys and biological samples of people with IgAN when they experience loin pain.
Study Type
OBSERVATIONAL
Enrollment
40
University Hospitals of Leicester
Leicester, Leicester, United Kingdom
Change in MRI-derived total kidney volume between active pain and follow-up assessments in participants with episodic loin pain
Differences in total kidney volume (mL)
Time frame: Within 72 hours of active loin pain onset and at follow-up assessment at least 2 weeks after the first visit.
Change in MRI-derived renal cortical volume between active pain and follow-up assessments in participants with episodic loin pain
Differences in renal cortical volume (mL)
Time frame: Within 72 hours of active loin pain onset and at follow-up assessment at least 2 weeks after the first visit.
Change in MRI-derived renal medullary volume between active pain and follow-up assessments in participants with episodic loin pain
Differences in renal medullary volume (mL)
Time frame: Within 72 hours of active loin pain onset and at follow-up assessment at least 2 weeks after the first visit.
Change in MRI-derived renal T1 relaxation time between active pain and follow-up assessments in participants with episodic loin pain
Difference in renal T1 relaxation time (ms)
Time frame: Within 72 hours of active loin pain onset and at follow-up assessment at least 2 weeks after the first visit.
Presence of renal pelvis abnormality on renal MRI in participants with episodic loin pain and participants with no history of loin pain
Presence of renal pelvis abnormality, including renal pelvis dilatation
Time frame: Within 72 hours of active loin pain onset and at follow-up assessment at least 2 weeks after the first visit.
Difference in MRI-derived total kidney volume between participants with episodic loin pain and participants with no history of loin pain
Difference in total kidney volume (mL)
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Time frame: Within 72 hours of pain onset for participants with episodic loin pain and baseline assessment after enrolment for participants with no history of loin pain.
Difference in MRI-derived renal cortical volume between participants with episodic loin pain and participants with no history of loin pain
Difference in renal cortical volume (mL)
Time frame: Within 72 hours of pain onset for participants with episodic loin pain and baseline assessment after enrolment for participants with no history of loin pain.
Difference in MRI-derived renal medullary volume between participants with episodic loin pain and participants with no history of loin pain
Difference in renal medullary volume (mL)
Time frame: Within 72 hours of pain onset for participants with episodic loin pain and baseline assessment after enrolment for participants with no history of loin pain.
Difference in MRI-derived renal T1 relaxation time between participants with episodic loin pain and participants with no history of loin pain
Difference in T1 relaxation time (ms)
Time frame: Within 72 hours of pain onset for participants with episodic loin pain and baseline assessment after enrolment for participants with no history of loin pain.
Assessment of organ-level changes between pain-prone patients and those with no history of loin pain using structural renal magnetic resonance imaging (MRI)
Presence of renal pelvis abnormality, including renal pelvis dilatation
Time frame: Within 72 hours of pain onset for participants with episodic loin pain and baseline assessment after enrolment for participants with no history of loin pain.
Untargeted Liquid Chromatography-Tandem Mass spectrometry (LC-MS/MS) analysis to analyse differences in the urinary proteome between an active pain episode and when it subsides
Differences in abundance ratios
Time frame: Within 72 hours of active loin pain onset and at follow-up assessment at least 2 weeks after the first visit
Untargeted Liquid Chromatography-Tandem Mass spectrometry (LC-MS/MS) analysis to analyse the differences in the urinary proteome between pain-prone patients and those with no history of loin pain
Differences in abundance ratios
Time frame: Within 72 hours of pain onset for participants with episodic loin pain and baseline assessment after enrolment for participants with no history of loin pain.
Assessing the difference in molecules of interest between an active pain episode and when it subsides using enzyme-linked immunosorbent assay (ELISA) in urine, serum, and plasma
Differences in concentrations (w/v)
Time frame: Within 72 hours of active loin pain onset and at follow-up assessment at least 2 weeks after the first visit
Assessing the difference in molecules of interest between pain-prone patients and those who do not have a history of loin pain using enzyme-linked immunosorbent assay (ELISA) in urine, serum, and plasma.
Differences in concentrations (w/v)
Time frame: Within 72 hours of pain onset for participants with episodic loin pain and baseline assessment after enrolment for participants with no history of loin pain.
Comparing the presence of urinary factors that indicate active intra-renal injury between an active pain episode and when it subsides using urine microscopy
Difference in abundance (count per high magnification field)
Time frame: Within 72 hours of active loin pain onset and at follow-up assessment at least 2 weeks after the first visit
Comparing the presence of urinary factors that indicate active intra-renal injury between an pain-prone patients and those with no history of loin pain using urine microscopy
Difference in abundance (count per high magnification field)
Time frame: Within 72 hours of pain onset for participants with episodic loin pain and baseline assessment after enrolment for participants with no history of loin pain.
Comparing the presence of urinary factors that indicate active intra-renal injury between an active pain episode and when it subsides using the urine dipstick test
Difference in presence (Yes/No)
Time frame: Within 72 hours of active loin pain onset and at follow-up assessment at least 2 weeks after the first visit
Comparing the presence of urinary factors that indicate active intra-renal injury between an pain-prone patients and those with no history of loin pain using the urine dipstick test
Difference in presence (Yes/No)
Time frame: Within 72 hours of pain onset for participants with episodic loin pain and baseline assessment after enrolment for participants with no history of loin pain.