CONTEXT.—: Glucose-6-phosphate dehydrogenase (G6PD) activity is used in the evaluation of hemolysis risk in patients being assessed for G6PD deficiency. A long-acting 8-aminoquinoline drug (tafenoquine) used in malaria treatment is contraindicated in patients with G6PD deficiency (<70% normal G6PD activity). The current state of G6PD reporting practices to support clinical eligibility assessment is poorly understood. OBJECTIVE.—: To assess clinical laboratory reporting practices for G6PD testing. DESIGN.—: In October 2019 and October 2020, voluntary questionnaires were distributed to 327 and 324 laboratories participating in the College of American Pathologists G6PD proficiency testing (PT). RESULTS.—: Two hundred fifty-seven and 119 laboratories responded to the 2019 and 2020 questionnaires, respectively. Few laboratories have received clinical questions about average normal G6PD activity (US/Canada, 2.0% [3 of 149]; international, 8.4% [9 of 107]), whereas slightly more have determined the average normal G6PD activity for their own assay and patient populations (US/Canada, 6.7% [10 of 149]; international, 19.4% [21 of 108]). Few laboratories report G6PD activity in percent of normal format (US/Canada, 2.7% [4 of 149]; international, 8.3% [9 of 108]). The most common unit of measurement in use for quantitative G6PD reporting is unit per gram of hemoglobin. Reference intervals vary based on assay, reaction temperature, and participant laboratory and demonstrate moderate correlation (r = .46-.51) to G6PD activity measured from a "normal" PT challenge specimen. Nearly half of participants (47.8% [85 of 178]) categorized a quantitatively "intermediate" G6PD PT challenge as "normal" when using qualitative assays. CONCLUSIONS.—: Percent of normal G6PD activity reporting would facilitate patient eligibility assessment for drugs, such as tafenoquine. Quantitative assays are better able to differentiate "intermediate" specimens than qualitative assays.

CONTEXT.—: Glucose-6-phosphate dehydrogenase (G6PD) activity is used in the evaluation of hemolysis risk in patients being assessed for G6PD deficiency. A long-acting 8-aminoquinoline drug (tafenoquine) used in malaria treatment is contraindicated in patients with G6PD deficiency (<70% normal G6PD activity). The current state of G6PD reporting practices to support clinical eligibility assessment is poorly understood. OBJECTIVE.—: To assess clinical laboratory reporting practices for G6PD testing. DESIGN.—: In October 2019 and October 2020, voluntary questionnaires were distributed to 327 and 324 laboratories participating in the College of American Pathologists G6PD proficiency testing (PT). RESULTS.—: Two hundred fifty-seven and 119 laboratories responded to the 2019 and 2020 questionnaires, respectively. Few laboratories have received clinical questions about average normal G6PD activity (US/Canada, 2.0% [3 of 149]; international, 8.4% [9 of 107]), whereas slightly more have determined the average normal G6PD activity for their own assay and patient populations (US/Canada, 6.7% [10 of 149]; international, 19.4% [21 of 108]). Few laboratories report G6PD activity in percent of normal format (US/Canada, 2.7% [4 of 149]; international, 8.3% [9 of 108]). The most common unit of measurement in use for quantitative G6PD reporting is unit per gram of hemoglobin. Reference intervals vary based on assay, reaction temperature, and participant laboratory and demonstrate moderate correlation (r = .46-.51) to G6PD activity measured from a "normal" PT challenge specimen. Nearly half of participants (47.8% [85 of 178]) categorized a quantitatively "intermediate" G6PD PT challenge as "normal" when using qualitative assays. CONCLUSIONS.—: Percent of normal G6PD activity reporting would facilitate patient eligibility assessment for drugs, such as tafenoquine. Quantitative assays are better able to differentiate "intermediate" specimens than qualitative assays.

Comment in J Urol. 2022 Feb;207(2):464-465.

Comment in Arch Pathol Lab Med. 2022 Jan 2;146(2):141b-143.

CONTEXT.—: Seminal vesicle invasion (SVI) as pT3b prostate cancer generally, but not uniformly, indicates poor prognosis. OBJECTIVE.—: To determine the clinical impact of pT3a lesions (ie, extraprostatic extension other than seminal vesicle or bladder invasion [EPE], microscopic bladder neck invasion [mBNI]), as well as unilateral (Uni) versus bilateral (Bil) SVI), in pT3b disease. DESIGN.—: We assessed radical prostatectomy findings and long-term oncologic outcomes in 248 consecutive patients with pT3b disease. RESULTS.—: Focal EPE, nonfocal EPE, mBNI, Uni-SVI, and Bil-SVI were identified in 13 (5.2%), 206 (83.1%), 48 (19.4%), 109 (44.0%), and 139 (56.0%) cases, respectively. Of possible combinations, we eventually divided our cases into 3 cohorts-Group 1: Uni/Bil-SVI and EPE-/mBNI- (n = 28; 11.3%); Group 2: Uni-SVI and EPE or mBNI (n = 103; 41.5%); and Group 3: Bil-SVI and EPE or mBNI (n = 70; 28.2%) or Uni/Bil-SVI and EPE+/mBNI+ (n = 47; 19.0%). Group 3 patients showed significant adverse histopathologic findings, compared with Group 1 or Group 2 patients. Kaplan-Meier analysis revealed that the prognosis was worse in the following order: Group 1, Group 2, and Group 3; and the differences in progression-free survival between any 2 groups were statistically significant. These significant differences were also seen in subgroups, such as those without or with adjuvant therapy before recurrence and those without lymph node metastasis. Additionally, Group 3 patients had a significantly higher risk of cancer-specific mortality than Group 2 patients. In multivariate analysis (Group 2 as a reference), Group 1 (hazard ratio [HR] = 0.169, P = .01) and Group 3 (HR = 1.620, P = .04) showed significance for progression. CONCLUSIONS.—: From these significant findings, we propose a novel pT3b subclassification, namely pT3b1 (Group 1), pT3b2 (Group 2), and pT3b3 (Group 3), which more accurately stratifies its prognosis.