[Artificial intelligence fluorescence method versus traditional flow cytometry for detection of sperm DFI in...

To explore the influence of oligospermia (OS) on the detection of sperm DNA fragmentation index (DFI) by fluorescence method based on artificial intelligence (AI) recognition and flow cytometry-based sperm chromatin structure assay (SCSA).

We collected semen samples from 201 males, including 50 azoospermia (AS) patients as negative controls, 90 OS patients (sperm concentration >0×10⁶/ml and <15×10⁶/ml), and 61 normal men (sperm concentration ≥15×10⁶/ml). Then we subdivided the OS patients into a mild OS (sperm concentration ≥10×10⁶/ml and <15×10⁶/ml), a moderate OS (sperm concentration ≥5×10⁶/ml and <10×10⁶/ml) and a severe/extremely severe OS group (sperm concentration >0×10⁶/ml and <5×10⁶/ml), with 30 cases in each group, and compared the results of DFI detection between the AI fluorescence method and traditional flow cytometry.

The DFI value detected by AI fluorescence method showed statistically significant difference from that detected by flow cytometry in the AS, moderate OS and severe/extremely severe OS groups (P<0.01), the former even lower than the latter, but not in the normal control and the mild OS groups (P > 0.05). In the AS group, a dramatically lower rate of non-0 results was achieved by AI fluorescence method than by flow cytometry (8% vs 100%, P<0.01). The DFI values detected by AI fluorescence method exhibited a good linear correlation to those obtained by flow cytometry in the normal control and mild OS groups (R2 = 0.7470; R2 = 0.7180), but a poor linear correlation in the OS full-sample, moderate OS and severe/extremely severe OS groups (R2 = 0.3092; R2 = 0.3558; R2 = 0.2147).

The AI fluorescence method has a higher specificity and is more suitable than flow cytometry for detection of sperm DFI in OS patients. The DFI values obtained by the two methods are consistent with sperm concentration ≥10×10⁶/ml, but the accuracy of the results of detection may be affected with sperm concentration >0×10⁶/ml and <10×10⁶/ml.