The Hypoosmotic Swelling Test (HOS test) is used to check male infertility as well as to assess sperm cell membrane function.
Water permeability is an important physiological property of all cell membranes including spermatozoa membranes. The membranes allow the selective transfer of fluids and molecules through them and in addition, the membrane of the spermatozoa seems to play a very important role during the fertilization process.
The Hypoosmotic Swelling Test is based on the ability of live spermatozoa to withstand moderate hypoosmotic stress. At moderate hypoosmotic stress, the membranes swell and reach a steady-state, and then any amount of fluid entering the cells is pumped out of the intact functional membrane. Spermatozoa swell to varying degrees at this stage but do not rupture. Dead spermatozoa whose membranes are not intact and functional do not swell in hypotonic media.
Low values in the HOS test are strongly correlated with an increased rate of damaged sperm DNA, as measured by the DNA fragmentation index (DFI). The test of hypoosmotic swelling of the spermatozoa can be used as an additional indicator of the vitality of the spermatozoa as well as for the diagnosis of abnormalities such as e.g. the immotile cilia syndrome.
The test of the hypoosmotic swelling of the spermatozoa is the most reliable indicator for the selection of the spermatozoon during the in vitro fertilization with the ICSI technique. There is a significant correlation between the percentage of spermatozoa that swell during the HOS test and the percentage of oocytes that are successfully fertilized.
Many recent studies suggest that high values in the HOS test are positively correlated with all key sperm quality factors (concentration, morphology, and sperm motility).
The results of laboratory tests are the most important parameter for the diagnosis and monitoring of all pathological conditions. 70-80% of diagnostic decisions are based on laboratory tests. The correct interpretation of laboratory results allows the doctor to distinguish "health" from "disease".
The results of laboratory tests should not be interpreted as the numerical result of an individual analysis. Test results should be interpreted in relation to individual and family history, clinical findings, and the results of other laboratory tests and information. Your GP can explain the importance of your test results.
At Diagnostiki Athinon we answer your every question regarding the examinations you do in our laboratory and we contact your doctor in order to have the best possible medical care.