Fortunato, who is not really the protagonist, has more in common with Poe than does Montresor. Fortunato most likely suffers from consumption, as did Poe's beloved young wife. Poe makes many references to Fortunato's coughing and inability to deal with the dampness of the passage. Additionally, Fortunato is drunk when Montresor leads him further into the catacombs. Poe writes that:
"[Fortunato] turned towards [Montresor], and looked into [his] eves with two filmy orbs that distilled the rheum of intoxication.
Poe himself was an alcoholic and seems to have realized the extremely negative effects that alcohol has on one's ability to reason. In "Cask," Fortunato is easily led to his death because of his intoxication. Similarly, in Poe's "The Black Cat," the narrator mentions that he is afflicted with the disease of alcohol.
If you need a comparison of Montresor and Poe, the most likely connection is that Montresor does mention that the wine that he drank himself starts to affect him as he leads Fortunato to his death.
Poe wrote “The Cask of Amontillado” in 1846 near the end of his life. His youth, besides being orphaned, was one of wealth, privilege and good fortune. After the collapse of his relationship with his foster father his life had changed, dramatically. He lived modestly if not in poverty throughout most of his life. In the story of “The Cask of Amontillado” there is two main characters Montresor and Fortunato both have similar backgrounds; wealthy aristocrats with similar hobbies. But yet their standing is different as Montresor states, “You are happy, as once I was. You are a man to be missed. For me it is no matter” (poe). This mirrors Poe’s life, once a wealthy southern gentleman and at the point he wrote this a failure living in poverty. Poe must have reflected on his life and realized that he had many opportunities in his life, that threw one of his vices he squandered them. Montresor was his present self and Fortunato was the fortunate young fool that wasted all the opportunities.