Tango Optimo

[efg21]

Hello all,

 

Just looking for some support on our Tango Optimo from biotest.  I have found that it does not always catch antibodies.  We have had it miss an E, and the screen cells have missed an Fya.   Has anyone else run into problems like this? Ive been searching the internet for awhile and havent got far so I'm trying a lab forum now so hopefully i can get some answers! 

 

also any tricks you have learned with the tango, anything at all to make me more efficient at it?

 

thanks!

[John C. Staley]

I won't be much help but keep in mind that no technology is 100% sensitive or 100% specific.  Your instrument will occasionally miss something.  I had a lot of problems from the corporate transfusion QA group when we first automated back in 1999.  They expected the instrument to be 100% and it simply was not.  Their expectations were far beyond the abilities of any technology.  I think it was the basic blood banker fear of change.  Luckily they got over it. 

 

It's always an excellent idea to check with other users for their experience and input.  I'm sure there will be a number of folks that can provide you with some real info and not just the philisophical drivel I provide. 

 

Good luck. 

[AMcCord]

Google for articles on Tango methodology and sensitivity - they're out there. I second the idea of checking with other users. 

 

John's philosophical 'drivel' is right on - nothing is going to be perfect. You'll have to consider whether or not the misses on antibody detection are excessive for the patient population you serve based upon your experiences.

[galvania]

Also - at least in terms of the E. What are you comparing against? Some methods are VERY sensitive at detecting E-like antibodies and cause no end of problems.

[tbostock]

Anti E is the only antibody that we "missed" on the Tango when doing our validation. It was only reacting at 1+ in gel. There are "enzyme-only" or E-like antibodies that gel are famous for picking up that other methods don't.

We have picked up plenty of Anti-E antibodies in our 2 years of using it, and as far as we know have not missed any that caused a patient any reaction.

We find that Anti-K and Anti-Fya and Anti-Fyb are stronger on the Tango. Anti-Jka can sometimes be one grade weaker. We don't detect cold agglutinins or rouleaux at all...really nice.

There is no perfect method or we would all be using it. I do like the Tango for its full menu, on board reagent storage for 7 days, ability to remove a sample from the analyzer, etc. Overall we are very happy with it, we use it for all tests including unit rechecks, DAT, Weak D, AHG crossmatch, antibody ID, and cord blood testing.

[profbaud]

We have had our Tango for 18 months and have not missed an antibody.  We did have some miscellaneous reactivity on one specimen that we had to repeat on the bench with tubes and 3 drops of patient plasma before we could identify the newly forming Anti-Jka.

I love my Tango.  We don't get the cold junk we used to get in Gel.

What help do you need?

[Malcolm Needs ☆]

I hate to be even more pedantic than normal (if that is possible) profbaud, but how do you know that you have not missed an antibody for 18 months?  If the tests are negative, then there may still be an antibody present, but you would not know, as the tests are negative.

[tbostock]

 

I hate to be even more pedantic than normal (if that is possible) profbaud, but how do you know that you have not missed an antibody for 18 months?  If the tests are negative, then there may still be an antibody present, but you would not know, as the tests are negative.

 

True, Malcolm. Patients tend to be discharged before they hit that 7-10 day window where we tend to start seeing a delayed hemolytic reaction. We pick up on one or two of these a year, but I wonder how many we never know about.

[David Saikin]

I like Malcolm's point . . . if your antbody screen is negative, how do you know if you've missed one - esp those that are not routinely on screening cells?  That's kind of like asking donor's if their sexual partner has engaged in sex for money or drugs, " how do you know"? 

[CAMLT]

I like Malcolm's point . . . if your antbody screen is negative, how do you know if you've missed one - esp those that are not routinely on screening cells?  That's kind of like asking donor's if their sexual partner has engaged in sex for money or drugs, " how do you know"? 

 

I agree. It is all about sensitivity. Any AB titter/strength less than the certain level, the analyser will not pick up. That is one factor to contribute the claim that transfusion is associated with risk for pt. Now, However, it is hard to get infor about the testing sensitivity for the reagents we use. Maybe it is because they cannot control the pt side since each pt is different. Now, if the company did not have a clue about testing sensitivity about their antisera, how can they be sure their reagents are potent enough in the real world? Well even they can prepare their controls to validate, but how low titter can go for these controls so they can be sure their antisera are potent enough? There must have some kind of guide line there for each company to make these reagents, but does FDA have this guideline?