Objective: We evaluated the effect of packed red cell transfusion (PCTx) on serum concentrations of gonadotropins luteinizing hormone and follicle-stimulating hormone (LH and FSH) and testosterone (T) levels and measured sperm parameters in young adults with sickle cell disease (SCD) CTSB on top-up transfusion (TTx) and those on exchange transfusion (ETx) regimen. last 4-5 years. Ten patients were on TTx and eight were on ETx regimen. BCX 1470 Results: PCTx significantly increased hemoglobin (Hb) from 8.5 ± BCX 1470 1.17 g/dl to 10.5 ± 0.4 g/dl T from 12.3 ± 1.24 nmol/L to 14.23 ± 1.22 nmol/L and gonadotropins’ concentrations. Sperm parameters improved significantly after PCTx including: total sperm count from 87.4 ± 24.6 BCX 1470 million/ml to 146.2 ± 51.25 million/ml total progressive sperm motility (TPM) from 40.8 ± 11.1 million/ml to 93.4 ± 38.3 million/ml rapid progressive sperm motility (RPM) progressive motility from 29.26 ± 8.75 million/ml to 67.4 ± 29 million/ml. After PCTx the total sperm count TPM and RPM were significantly better in the ETx group versus the TTx group. Before and after PCTx T concentrations were correlated significantly with sperm total count volume TPM and RPM (= 0.53 0.55 0.42 and 0.38 respectively < 0.01). Hb concentrations were correlated significantly with sperm count TPM RPM and % of sperms with normal morphology (= 0.60 0.69 0.66 and 0.86 respectively < 0.001). Conclusion: Our study suggests that in males with SCD blood transfusion is associated with significant acute enhancement of sperm parameters and with increased concentrations of serum T LH and FSH. Improvement of sperm parameters were significantly better in the ETx group verses the TTx group. These “acute” effects on spermiogenesis are reached with an unknown mechanism/s and suggest a number of pathways that need further human and/or experimental studies. < 0.05 was chosen as the limit of significance). RESULTS All patients with SCD (= 18 age 20.7 ± 2.9 year) had a normal sexual development (Tanner's stage 5) with normal secondary sex characteristics normal testicular volume (17.4 ± 3.1 ml) and were able to ejaculate. None of the 18 patients had oligospermia asthenozoospermia teratospermia or asthenoteratozoospermia. After PCTx significant increase of Hb from 8.5 ± 1.2 g/dl to 10.5 ± 0.4 g/dl was associated with increased concentrations of T BCX 1470 (from 12.3 ± BCX 1470 1.2 nmol/L to 14.2 ± 1.2 nmol/L) LH (from 4.4 ± 0.9 U/L to 5.7 ± 0.85 U/L) and FSH (from 5.4 ± 1.46 U/L to 6.6 ± 1.8 U/L). Total sperm count increased significantly from 87.4 ± 24.6 million/ml to 146 ± 51 million/ml and rapid progressive sperm motility (RPM) increased from 29.3 ± 8.75 million/ml to 67.4 ± 29.1 million/ml [Table 1]. Table 1 Hormonal and sperm parameters in patients with sickle cell disease before and after transfusion Comparison between the two study groups (ETx vs. TTx) revealed that after PCTx patients on ETx had significantly better semen parameters including total sperm count total progressive sperm motility (TPM) RPM and percentage of sperms with normal morphology [Table 1]. Gonadotrophins and T concentrations did not differ among the two groups. Before and after PCTx T concentrations were correlated significantly with sperm total count volume TPM and RPM (= 0.53 0.55 0.42 and 0.38 respectively P: 0.01). Before and after PCTx Hb concentrations were correlated significantly with Sperm count TPM RPM and percentage of sperms with normal morphology (= 0.60 0.69 0.66 and 0.86 respectively < 0.001) [Figures ?[Figures11 and ?and22]. Figure 1 Regression of sperm parameters on hemoglobin (Hb) levels: (a) Regression of total sperm count on Hb levels. (b) Regression of total progressive sperm motility on Hb levels. (c) Regression of rapid progressive sperm motility on Hb levels. (d) Regression ... Figure 2 Regression of sperm parameters on testosterone (t) levels: (a) Regression of total sperm count on T levels. (b) Regression of total progressive sperm motility on T levels. (c) Regression of rapid progressive sperm motility on T levels. (d) Regression ... DISCUSSION Infertility is a major problem in SCD patients especially in males. In addition to low serum T other abnormalities involving the accessory sex organs such as the seminal vesicles and the prostate gland as well as marked decrease in ejaculate volume and sperm parameters may be BCX 1470 observed in male patients.[3 4 5 6 7 8 9 10 11 12 13 14 15 26 Recently some data showed that blood transfusion produce significant acute changes in the hormonal milieu and sperm parameters of patients with chronic hemolytic anemia.[27 28 29 Therefore we studied the acute effects of PCTx on spontaneous spermatogenesis and pituitary testicular axis in young eugonadal males with transfusion-requiring SCD (10 were on TTx and eight were on ETx). Significant.