Hello,
This is really a difficult situation to diagnose and as your physician advised the best way to reach the diagnosis is by kidney biopsy.
However, I would like to give you a list of some of the possible causes that might help you be sure that all possible causes have been excluded by conventional investigations as you mentioned.
-Blood clots in urine usually indicate a cause below the kidney.
-Frank hematuria due to kidney glomerular causes is not painful.
-Urinary tract infection presents with dysuria,
fever, pelvic
pain and hematuria.
-An early-morning periorbital edema, dark-colored concentrated urine are seen in kidney glomerular cause.
-Hematuria and
anemia with low platelt count is seen in hemolytic uremic syndrome.
-Post infectious glomerulonephritis usually occur after sore throat or skin infection.
-Systemic conditions like
SLE and Henoch-Schönlein purpura are usually associated with joint
pain, skin rash
-Familial disease are suspected when a positive family history of renal disease is found like collagen vascular diseases, stones, or polycystic kidney disease.
-Autoimmune diseases characterized by increase level of IGA are diagnosed by serology blood testing and kidney biopsy.
So,
CBC and blood film (smear), complement tests, IgA level,
ESR,
LDH ASO, ANA, DsDNA, and urine analysis and culture are among the essential investigations.
When results are not conclusive, kidney biopsy is essential for diagnosis and proper treatment.
Hope you find this information useful.
I advise you to follow up with your Doctor and to discuss with him your concerns.
Please keep us updated.
Best regards.
This answer does not substitute for direct medical consultation.
Dr. Safaa Mahmoud.
MB BCh, MSc Internal Medicine. MD Medical Oncology.
PhD Experimental Medicine and Biochemical Science.