Sensitive LH and FSH assays for monitoring low serum levels in men undergoing steroidal contraception.
OBJECTIVE
Current immunoassays for detecting serum FSH and LH are not sufficiently sensitive to detect the markedly reduced levels in men undergoing steroidal hormonal treatment for contraceptive purposes. The purpose of this study was to increase the sensitivity of available LH and FSH immunofluorometric (Delfia) assays in order to allow a better understanding of the importance of gonadotrophin suppression in achieving the optimal suppression of sperm count.


METHODS
Assay conditions were modified by increasing serum sample volume, the inclusion of either FSH- or LH-depleted serum to reduce the resulting matrix effects and extending incubation times. The microassays were applied to serum from 10 men administered testosterone enanthate with or without depot medroxyprogesterone acetate for 12 weeks as part of a contraceptive trial.


RESULTS
The assay sensitivities were increased to 0.005 IU/l for LH and 0.010 IU/l for FSH, representing a five- to six-fold increase in sensitivity compared with existing assays. In the clinical trial, serum LH levels were suppressed to near or below the level of assay detection (mean 0.014 IU/l < 0.4% of pretreatment values) while in eight of 10 men, plasma FSH levels were detectable (0.04-0.07 IU/l, 1-5% of pretreatment values). These FSH levels would not have been detected by current assays.


CONCLUSIONS
The increased sensitivities of the LH and FSH assays enabled the detection of gonadotrophins that were < 0.4% of pretreatment serum levels. Using these methods, serum LH was suppressed to nondetectable or near nondetectable levels while serum FSH was highly suppressed but still detectable in the majority of men undergoing steroidal treatment for contraceptive purposes.
Robertson
D M
DM
Prince Henry's Institute of Medical Research, Monash Medical Centre, Clayton, Victoria, Australia. david.robertson@med.monash.edu.au
Pruysers
E
E
Stephenson
T
T
Pettersson
K
K
Morton
S
S
McLachlan
R I
RI
D003272:Contraceptive Agents, Male / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D015200:Fluoroimmunoassay / Q000379:methods; D005640:Follicle Stimulating Hormone / Q000097:blood*; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood* / Q000187:drug effects; D008297:Male; D017258:Medroxyprogesterone Acetate / Q000494:pharmacology; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D013076:Sperm Count; D013739:Testosterone / Q000031:analogs & derivatives / Q000494:pharmacology*
D003272:Contraceptive Agents, Male; D011933:Reagent Kits, Diagnostic; D013739:Testosterone; C004648:testosterone enanthate; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D017258:Medroxyprogesterone Acetate