No. Altruism is, from its most fundamental definition, an imaginary concept.
"unselfish regard for or devotion to the welfare of others"
ALL acts have some positive effect for the one doing the action, regardless of how the effect takes place. Mental positive effects such as self-esteem boosts count. Sacrificing yourself by stepping in front of a bullet for someone? You feel good because you sacrificed yourself, doing the "right thing to do". Taking all the blame for something you had nothing to do with? Making someone else feel good makes you feel good. There is no escaping the impossibly seamless confines of self-benefit.
However, altruism exists in two other forms.
The first is a loose definition of the word. Total unselfishness is impossible... however there is weighing off cost vs gain. If you take the definition of unselfishness as merely "cost outweighing gain" rather than "all cost and no gain", then altruism is indeed possible. In fact, this "altruism", if it can be called that, happens every day. Many people, knowingly or unknowingly, cost themselves more than they gain. Regardless, this idea cannot be accepted as legitimate altruism, since even though you are adhering to the definition of the concept, you are bending the definition of a key point of the concept.
The second is the more theoretically perfect form of plausible altruism. You may not know it takes place, but it happens all the time. People have been complaining about it since the dawn of human communication. This debate we are all engaging in happens to utilize it in many forms.
Have you guessed it yet? The only actual altruism that exists is the opposite; selfishness.
Isn't it ironic that altruism only takes place as the inverse affect of its inverse? The limitation with personally inflicted altruism is that it always has personal benefits, as said before. But what if you are MAKING someone behave altruistically? Taking something important to them away, something they would NEVER give up? Let's say you love pokemon cards. Your friend has a holographic charizard or whatever the kids use these days. You DON'T. So you take his. Your friend was extremely fond of his charizard and would never give it to you for no reason, so he starts crying and then never talks to you again because of his hate of you.
Stop. Getting that charizard felt good, yes? Your conscience may give you regret, but say you think your friend is overreacting. Say, your friend accidentally ripped up a rare card you once had unknowingly, and you stayed angry at him while he went unawares that he damaged your feelings. So you find it to be fitting to take his card in return. But he knew nothing of hurting your feelings earlier. So you now feel good for taking his card, while he feels completely hurt by your actions and consumed with negativity.
Hmm, what's that? You feel good and your friend feels bad? Or rather, thinking from the perspective of the friend, you feel bad and your friend feels good. That sounds a bit like
"unselfish regard for or devotion to the welfare of others"
to me, doesn't it? Even if the regard is intentional or not, in YOUR charizard being in your FRIEND'S care, you are being completely unselfish. Your allowing of the charizard to be stolen, either by carelessness or trickery on your friends part, is unintentional regard for your friend's welfare (his agenda for his own welfare provides his positive benefit).
This can happen in other ways. Say you lose something very dear to you on the way to the bus stop. A picture of you and your long lost sister, whom you presume to be dead after a car accident a decade ago. You get on the bus and go home, then hours later realize it is missing. You go back but it is gone. You are gripped by the sadness of losing the only physical manifestation of your only family member you ever knew personally, your sister. You cry and cry and cry and sink into yourself.
Meanwhile, by incredible chance, your sister (who was supposedly dead) was the one who picked up the portrait near the bus stop. She becomes ecstatic with joy at the sight of the picture, as she had longed for many years to find some hint of you anywhere. She becomes a much happier person after that, and strives to try and find you (the story ends there).
So, your misfortune led to your sister's great happiness. What does this all mean? It means that true altruism, in its most pure and clear form, is only possible when the person to behave altruistically is doing it without knowledge of doing it. It means you can only be altruistic in BEING hurt, not hurting yourself. That makes all the difference.
Come to think of it, it kind of makes sense why many religions who take altruism as a "holy" characteristic hurt their followers, yes? "The greater good", I believe it is called.