Faint ELISA FeLV+ kitten, PCR negative

[veguis]

Hello The Cat Site! New poster here!

A week ago, I decided to check if my kitten Nemo had leukemia because in the future he was going to live with another 10 month old cat that currently lives with my parents (Nemo is 4 months old). We already had a cat two years ago that died from complications derived from FeLV, she was our first pet and the pain we felt when we lost her was so intense that the mere possibility that Nemo could infect our other cat had us very worried.

Well, we received the news that Nemo was positive through a point-of-care ELISA test, although it was a very faint positive (a specific perspective and lighting was needed to see it). The test was an URANOTEST FeLV-FIV

Upon seeing the result, the veterinarian immediately recommended sending a blood sample to the laboratory to confirm the result, this time by PCR. Well, they just called me this morning to tell me that the result was totally negative, no trace of viral copies!

As I understand, in the case of having an abortive reaction to the virus he should not have tested positive in the first ELISA test (presence of p27 antigens, so the virus was there eventually). We rescued him from the street when he was only 2 months old, so he had been with me for 2 months at the time of the test (strictly indoor).

I'm going to talk to my vet this afternoon, but I guess I shouldn't put the two cats together until a retest in a few months. The other cat is fully vaccinated, but we don't want to take any chances.

About Nemo's health condition:
- No anemia. Pink gums with no trace of gingivitis or bad smell.
- Good appetite, he eats his daily rations and always has room for a little more. Perfect poop
- He always wants to play, either with toys or running around the house at full speed.
- Good coat, no trace of grease. When he gets tired of grooming himself, he takes the opportunity to groom me too.
- He weighs 2.4kg at 4 months of age (he is a mixed tabby).

So he doesn't seem to show absolutely no symptoms.

Have you heard of similar cases?
Could Nemo have beaten the virus, or is he in a regressive state?
I am from Spain, so the prevalence of the virus is quite low (2.6% according to a recent pan-European study). Could it even be a false positive?

FeLV is a disease for which there is no cure as of today, so I think any discussion about it can be useful for cat owners who find themselves in a similar situation. Best regards!

 

[Antonio65]

Hi and welcome to TCS.

A faint positive ELISA test and a negative PCR test might mean your cat could be negative. I rely on PCR tests more than ELISA tests, but your Nemo is still rather young and generally vets do not think an ELISA test is totally reliable before 6 months of age.
I would wait at least another moth beofre retesting him.

I know it's a different sotry, my cat tested positive to FIV when she was very young, she tested negative two months later, but we had to run a PCR test to make sure she was actually negative.

 

[fionasmom]

Welcome to The Cat Site! I am sorry that you have ended up in this gray area with your cat and it is worrisome. I would do exactly as was suggested and retest with the PCR. Many vets do not consider one positive on one FeLV test alone to definitively show that the condition exists. False positives are said to occur more frequently than false negatives.

 

[dolceshmolce]

My 7 month old kitten had 2 positive ELISA’s when he was younger and was deemed a true positive. I went to another vet and she ran a PCR which came out negative & then ran another ELISA last week which is still coming out positive. With this combo she believes he has a regressive infection, which basically means his immune system is strong enough to keep the virus “deactivated” in his bone marrow. When a FeLV cat has a regressive infection, it is very unlikely that they are contagious. She did say that if he is under stress or gets sick, there is a chance it can be reactivated and become a progressive infection. However, research is showing that the viral protein degrades over time, so as time goes on, he is less likely to become progressive and could even have a chance at clearing the virus!
My cat does have some chronic diarrhea that we are trying to figure out and battled some nasty giardia for the first few months of his life, but other than that, his blood work and other bio markers look great now. We actually have an older FeLV- cat (he is vaccinated) as well, which of course brings some extra risk, but we decided that we couldn’t part with our little guy. But that is a personal decision, of course.
I’m not saying this is exactly what is going on with your kitty, but I do say this to bring some hope Also, false positive ELISAs can definitely happen!