RESUMO
The presence of latent fibrin clots is a recognised pre-analytical factor that causes inaccurate immunoassay results. This report details a case of a patient with Graves' disease and congenital dysfibrinogenemia (CD) that had serum thyroid function test results (TFTs) that were not in keeping with clinical signs or symptoms. Analysis of plasma samples taken from the patient was shown to provide more accurate results than those obtained using serum samples. Further cases of patients with CD, all sharing the same genetic mutation of fibrinogen, and discordant TFTs are described, where TFTs measurement in serum samples proved to be unreliable. Despite evidence of fibrin effecting immunoassays, this is the first report of its kind linking CD to erroneous immunoassay results. The mechanism is postulated to be related to atypical forms of fibrinogen resulting in latent fibrin in serum samples blocking the antigen binding site and leading to incorrect results. Congenital dysfibrinogenemia is asymptomatic in most patients and therefore abnormal, albeit inaccurate, TFTs may be the first finding. Recognition of CD as a cause of discordant results is important when interpreting TFTs to avoid unnecessary investigations and inappropriate clinical interventions to those with the disorder and potentially identify undiagnosed cases.
RESUMO
OBJECTIVE: Symptomatic hypogonadism discourages men from stopping anabolic-androgenic steroids (AAS). Some men illicitly take drugs temporarily stimulating endogenous testosterone following AAS cessation (post-cycle therapy; PCT) to lessen hypogonadal symptoms. We investigated whether prior PCT use was associated with the normalization of reproductive hormones following AAS cessation. METHODS: Retrospective analysis of 641 men attending a clinic between 2015-2022 for a single, nonfasting, random blood test <36 months following AAS cessation, with or without PCT. Normalized reproductive hormones (ie, a combination of reference range serum luteinizing hormone, follicle-stimulating hormone, and total testosterone levels) were the surrogate marker of biochemical recovery. RESULTS: Normalization of reproductive hormones was achieved in 48.2% of men. PCT use was associated with faster biochemical recovery (13.0 (IQR8.0-19.0) weeks, PCT; 26.0 (IQR10.5-52) weeks, no-PCT; P < .001). Odds of biochemical recovery during multivariable analysis were: (1) higher with PCT (OR3.80) vs no-PCT (P = .001), in men stopping AAS ≤3 months previously; (2) reduced when 2 (OR0.55), 3 (OR0.46), or 4 (OR0.25) AAS were administered vs 1 drug (P = .009); (3) lower with AAS >6 vs ≤3 months previously (OR0.34, P = .01); (4) higher with last reported AAS >3 months (OR 5.68) vs ≤3 months (P = .001). PCT use was not associated with biochemical recovery in men stopping AAS >3 months previously. CONCLUSION: Without evidence-based withdrawal protocols, men commonly try avoiding post-AAS hypogonadism with PCT, which is illicit, ill-defined, and not recommended. Only half of men had complete biochemical testicular recovery after stopping AAS. The surprising association of self-reported PCT use with short-term biochemical recovery from AAS-induced hypogonadism warrants further investigation.