Zsolt P. Nagy

Quality of frozen-thawed testicular sperm and its preclinical use for intracytoplasmic sperm injection into in vitro-matured germinal-vesicle stage oocytes.

OBJECTIVE To study the effects of cryopreservation on the quality of human testicular spermatozoa and the efficiency of intracytoplasmic sperm injection (ICSI) with frozen-thawed testicular sperm into metaphase II oocytes in vitro-matured from the germinal-vesicle stage oocyte. DESIGN Preclinical freezing study on supernumarary testicular spermatozoa after ICSI. SETTING Tertiary IVF center coupled with an institutional research environment. PATIENT(S) Twenty-nine patients undergoing excisional testicular biopsy for ICSI. INTERVENTION(S) Isolated testicular spermatozoa were cryopreserved and thawed; frozen-thawed motile testicular spermatozoa were microinjected. MAIN OUTCOME MEASURE(S) Prefreezing and post-thawing motility and viability, survival rate, fertilization rate, cleavage rate, and embryo quality after ICSI. RESULT(S) Mean percentage motility decreased from 21% before freezing to 6% after thawing. Vitality was impaired to a similar extent, decreasing from 68% to 22% (32% recovery rate). Injection of frozen-thawed testicular spermatozoa into in vitro-matured oocytes resulted in a fertilization rate of 50.9%. Cleavage rate was severely impaired. Half of the fertilized oocytes became arrested in the one-cell stage. CONCLUSION(S) Despite the low quality of the fresh testicular spermatozoa, a high percentage of prepared testicular sperm fractions showed survival and motility after the freezing and thawing process. Injection of frozen-thawed testicular sperm into matured oocytes resulted in fertilization rates comparable with these with fresh testicular sperm, but cleavage rates were severely impaired, which might be due to source of oocytes used for ICSI.

The use of testicular sperm for intracytoplasmic sperm injection in patients with necrozoospermia.

OBJECTIVE To investigate whether intracytoplasmic sperm injection (ICSI) using testicular spermatozoa from necrozoospermic patients results in acceptable fertilization and transfer rates. DESIGN Retrospective clinical study. SETTING Tertiary referral center. PATIENTS Five patients presenting consistently with 100% dead spermatozoa in their ejaculates. INTERVENTIONS In seven treatment cycles, an open testicular biopsy was performed to increase the chances for retrieving viable spermatozoa which were used for ICSI. MAIN OUTCOME MEASURES Sperm recovery, fertilization, and transfer rates. RESULTS Testicular sperm were recovered in all treatment cycles and fertilization occurred in six of seven cycles. Overall normal fertilization and transfer rates were 67% and 71%, respectively. One live birth was obtained after five ETs. CONCLUSION We recommend testicular sperm recovery for ICSI in patients who invariably or occasionally present with absolute necrozoospermia.

An improved treatment procedure for testicular biopsy specimens offers more efficient sperm recovery: Case series

OBJECTIVE To report an improved sperm recovery procedure from testicular biopsy specimens for intracytoplasmic sperm injection (ICSI). DESIGN Case series and controlled study. SETTING Procedures were performed in a tertiary IVF center. PATIENT(S) Nonobstructive azoospermic cases (15 patients) and obstructive azoospermic cases (5 patients). INTERVENTION(S) Intracytoplasmic sperm injection was carried out using testicular sperm isolated from a testicular biopsy specimen either with or without erythrocyte lysing buffer treatment. MAIN OUTCOME MEASURE(S) The time required to collect spermatozoa and the intactness and fertilization and developmental rates of oocytes. RESULT(S) In 7 of the 15 nonobstructive cases, it was possible to perform ICSI when, after shredding of the testicular tissue, no (or virtually no) sperm were present. There was no difference in the fertilization rates (83% and 68%) and developmental rates (87% and 89%) of the 54 sibling oocytes from another 5 patients in whom ICSI was carried out with sperm either treated or not treated with erythrocyte lysing buffer. CONCLUSION(S) Erythrocyte lysing buffer treatment of testicular biopsy specimens enhances the efficiency of sperm collection in those cycles in which spermatozoa are present and does not affect fertilization and embryo development.

Complementation of HLA-DQA and -DQB genes confers susceptibility and protection to insulin-dependent diabetes mellitus

Lack of an aspartic acid 57 in the HLA-DQ beta chain was introduced as a genetic marker of insulin-dependent diabetes mellitus (IDDM). Because 25% of the control population carries the same marker, we analyzed the DQ locus for the presence of more specific disease susceptibility markers, taking into account a possible role for the polymorphic DQA gene. We thereby identified the DQA3-DQB3.2/DQA4.1-DQB2 (DQA1*0301-DQB1*0302/DQA1*0501-DQB1*0201) genotype which was detected in 30% of the 268 typed IDDM patients and only in 1% of the 331 typed healthy controls, resulting in a relative risk of 35. This genetic marker was more frequent in patients with clinical onset before age 18 years (36%) than in patients diagnosed between age 18 and 40 years (22%) and was not observed in patients with non-IDDM. The new susceptibility genotype DQA3-DQB3.2/DQA4.1-DQB2 (DQA1*0301-DQB1*0302/DQA1*0501-DQB1*0201) may explain the well-known excess of DR3/DR4 heterozygous IDDM patients and is expected to help identify individuals at risk for developing the disease.