Mp19-05 Cryptospermia Is Associated With Significantly Higher Sperm Retrieval Rates When Compared to Patients With Azoospermia

Abstract

Non-obstructive azoospermia (NOA) is classified upon histology. However, significant heterogeneity exists within each testis. We hypothesize that histological evaluation misdiagnoses numerous men based upon a more comprehensive genetic phenotype. The objective of this study was to evaluate the discrepancies among histologic and genetic phenotyping of NOA patients.METHODS: In a prospective blinded study, 54 men presenting with NOA underwent testis biopsy at the time of surgical sperm retrieval. Tissue was sent for histology or RNA sequencing. Histological classification was performed by examining 9 discrete regions by 2 fellowshiptrained GU pathologists, at a tertiary care facility. RNA libraries were created and bulk next-generation RNA sequencing was performed using an Illumina HiSeq 2000 platform. Reads were mapped using TopHat (v2.0.8), quantified with Cufflinks, and normalized as FPKMs. Results underwent principal component analysis (PCA), and hierarchical clustering analysis using iDEP 0.42 to evaluate the relatedness of genomic phenotypes compared to histologic phenotypes.RESULTS: 21879 transcripts were mapped among the specimens. PCA demonstrated that Sertoli Cell Only (SCO) patients group tightly together, while early and late maturation arrest (MA) both group together. However, Klinefelter Syndrome (KS) grouped between SCO and normal (NL) while hypospermatogenesis (HS) was extremely variable, and was distributed among SCO, NL and MA groupings. Hierarchical clustering demonstrated significant heterogeneity between and within histologic classes. 4 second order hierarchical branches were identified. The first cluster contained 9 normal specimens, 3 HS and 1 late MA. The second cluster was comprised of 1 KS and 1 HS patient. The third cluster was predominantly SCO and was comprised of 10 SCO, 6 KS, and 3 HS patients. The fourth cluster was largely defined by maturation arrest with 11 early MA, 4 late MA, 3 HS, 1 normal and 1 SCO.CONCLUSIONS: Our results suggest that NOA subtypes broadly cluster together; however, a significant number of discrepancies exists between genomic clustering compared to conventional histologic classification. These findings identify the need for further research in refining the precision and reproducibility of sub-classification in NOA.