The Addis Count (HLM Test): Principles, Clinical Applications, and Diagnostic Value in Urinary Disorders
Aim
Assess the severity of glomerular renal disease , confirm a urinary tract infection , suspect urinary tuberculosis , interstitial nephropathy or urinary tract disease.
Principle
This test consists of counting red blood cells and leukocytes in urine collected over a limited and well-defined time, generally 3 hours or 180 minutes.
Practical implementation and sampling
The subject must be able to hold their urine for a few hours and urinate spontaneously (no catheter). This test should not be performed during menstruation in women.
After completely emptying the bladder and drinking 2 or 3 glasses of water, the subject remains lying down for 2 or 3 hours. After washing the meatus or glans, take a urine sample . The volume obtained is noted V (in liters).
Results and calculations
When counting by cell, the results are obtained in mm 3 , the number obtained is multiplied by 10 6 and the result is obtained in liters. This result is multiplied by the volume V obtained during the collection and then divided by the number of minutes during which the collection was carried out. We obtain the count in elements per minute.
Normally, less than 1,000 red blood cells and 1,000 white blood cells per minute should be found. In practice, only figures above 5,000 are considered pathological.
Causes of errors
Failure to adhere to the strict lying position during the test.
Interpretation and interest
This test is more accurate than the urine red blood cell and white blood cell count because it expresses a flow rate and not a concentration. Results around 5,000/min deserve confirmation.
A fundamental examination in the exploration of a glomerular disease, its importance is less great in urinary infections (leukocytes and red blood cells are evaluated by microscopic field during the Cyto-Bacteriological examination of Urine). However, it becomes necessary in the event of the absence of germs in the bacteriological examination (leukocyturia without germs: suspicion of tuberculosis or chlamydia infection).
This test is of no use in macroscopic hematuria.