Objective—To compare the ease of use and accuracy of 5 feline AB blood-typing methods: card agglutination (CARD), immunochromatographic cartridge (CHROM), gel-based (GEL), and conventional slide (SLIDE) and tube (TUBE) agglutination assays.
Sample Population—490 anticoagulated blood samples from sick and healthy cats submitted to the Transfusion or Clinical Laboratory at the Veterinary Hospital of the University of Pennsylvania.
Procedures—Sample selection was purposely biased toward those from anemic, type B, or type AB cats or those with autoagglutination. All blood samples were tested by use of GEL, SLIDE, and TUBE methods. Fifty-eight samples were also tested by use of CARD and CHROM methods. The presence of alloantibodies in all cats expressing the B antigen as detected by use of any method was also assessed.
Results—Compared with the historical gold-standard TUBE method, good to excellent agreement was achieved with the other typing tests: CARD, 53 of 58 (91% agreement); CHROM, 55 of 58 (95%); GEL, 487 of 490 (99%); and SLIDE, 482 of 487 (99%; 3 samples were excluded because of autoagglutination). Four of the samples with discordant test results originated from cats with FeLV-related anemia.
Conclusions and Clinical Relevance—Current laboratory and in-clinic methods provide simple and accurate typing for the feline AB blood group system with few discrepancies. Retyping after in-clinic typing with the GEL or TUBE laboratory methods is recommended to confirm any type B or AB cats.
Objective—To compare accuracy and ease of use of a card agglutination assay, an immunochromatographic cartridge method, and a gel-based method for canine blood typing.
Sample—Blood samples from 52 healthy blood donor dogs, 10 dogs with immune-mediated hemolytic anemia (IMHA), and 29 dogs with other diseases.
Procedures—Blood samples were tested in accordance with manufacturer guidelines. Samples with low PCVs were created by the addition of autologous plasma to separately assess the effects of anemia on test results.
Results—Compared with a composite reference standard of agreement between 2 methods, the gel-based method was found to be 100% accurate. The card agglutination assay was 89% to 91% accurate, depending on test interpretation, and the immunochromatographic cartridge method was 93% accurate but 100% specific. Errors were observed more frequently in samples from diseased dogs, particularly those with IMHA. In the presence of persistent autoagglutination, dog erythrocyte antigen (DEA) 1.1 typing was not possible, except with the immunochromatographic cartridge method.
Conclusions and Clinical Relevance—The card agglutination assay and immunochromatographic cartridge method, performed by trained personnel, were suitable for in-clinic emergency DEA 1.1 blood typing. There may be errors, particularly for samples from dogs with IMHA, and the immunochromatographic cartridge method may have an advantage of allowing typing of samples with persistent autoagglutination. The laboratory gel-based method would be preferred for routine DEA 1.1 typing of donors and patients if it is available and time permits. Current DEA 1.1 typing techniques appear to be appropriately standardized and easy to use.
To describe clinical findings, diagnosis, treatment, and survival in 18 cats with anemia of suspected immune-mediated origin (ASIMO) and conflicting results using FeLV diagnosis tests, and to suggest an accurate way to assess their FeLV diagnosis.
Medical records from 5 veterinary institutions were retrospectively reviewed to identify cats with ASIMO, positive results on p27 SNAP ELISA, and negative results on pro-virus PCR testing in peripheral blood, in the absence of other identified triggers. Follow-up was recorded from diagnosis to the time of writing, and survival analysis was performed to assess similarities with previous published data.
18 cats were enrolled from referral centers in Spain, Italy, and the United Kingdom. Both peripheral immune-mediated hemolytic anemia (IMHA; 12/18) and precursor targeted immune-mediated anemia (PIMA; 6/18) were described. When the SNAP ELISA test was rechecked in patients with disease control, SNAP ELISA positive results had become negative. Two cats had a relapse of the ASIMO, and the FeLV SNAP ELISA tested positive again. Other signs of FeLV disease did not appear in any of these patients despite immunosuppression. 14 cats (14/18 [78%]) were alive at the time of writing, and the mean estimated survival time was 769 days.
This study describes incongruent FeLV results in cats with ASIMO. It supports the necessity to confirm FeLV SNAP ELISA positive results using additional tools, such as pro-virus PCR testing, as different p27 point-of-care and external serological tests may be inconsistent.