Integra is apparently a descendent of Professor Abraham Van Helsing, one of the major characters from Bram Stoker's novel, Dracula.

In the novel, Van Helsing is a genius living in Amsterdam: he has a variety of degrees and honors, and he is a doctor, philosopher, metaphysician, and "one of the most advanced scientists of his time." Although he calls himself an old man, he is described as having "iron nerve", the "temper of the ice brook", "indomitable resolution", "self-command", "toleration exalted from virtues to blessings", and "the kindest and truest heart that beats." Even though his English is imperfect, he is an eloquent and passionate speaker. He is somewhat reserved around strangers, but he is always polite and kind.

Physically, Van Helsing is of medium height, strongly built, and has red hair and blue eyes. Mina Harker, in her journal, has a good description of his physical appearance.

Van Helsing is the close friend and former teacher of Dr. John Seward. At Seward's request, Van Helsing is called to England to examine Lucy Westenra after she falls mysteriously ill. He recognizes that Lucy has lost a significant amount of blood, and although he forms some suspicions about her illness after seeing two puncture marks on her neck, he refuses to explain anything to Seward. However, everything that Van Helsing does is for a reason. Van Helsing, of course, suspects that Lucy is being attacked by a vampire.

His fight to save Lucy's life is an uphill/downhill battle. Every time he seems to be succeeding, something sets him back. He has four men, including himself and the three men who love Lucy, give her blood transfusions at separate times to save her. For protection, he has Seward watch over her during the night (Seward, on the third night, fails to do so, and Lucy becomes ill) and places garlic in her room (Lucy's mother, on the first night of this, opens Lucy's window and removes the garlic). His battle, however, is a losing one, and eventually, Van Helsing recognizes that Lucy has become a vampire herself. He tells everyone that she will die soon, and she does.

One of Van Helsing's most notable traits is his open-mindedness. Van Helsing is willing to believe that there are things in this world that cannot be explained by science or other means. Although Seward and the others think he is crazy, as he tells Seward, "I want you to believe.... To believe in things that you cannot." Thus, Van Helsing correctly recognizes that he is dealing with vampires and the "Un-Dead." He has learned much from folk lore and legend, so he knows what vampires can do (can assume the shapes of dogs, bats, and mist; are super strong; are sly and cunning; have no reflection), what they fear and hate (garlic, crucifixes, the daytime), and how to kill them, (one must remove their hearts or drive a wooden stake through them, then cut off their heads and stuff their mouths with garlic).

Later, reports appear about children being led away by the "Bloofer Lady," only to be found later with twin puncture marks in their neck. Van Helsing realizes that Lucy is at work. He explains to Seward his conclusions, then leads Seward to Lucy's tomb, where they discover that her body is missing from her coffin; the next day, her body has mysteriously returned, but it looks as if she were alive. Van Helsing then explains to Quincey Morris and Arthur Holmwood the same, and although they, too, believe he's mad, they reluctantly accompany him to her tomb. Again, her body is missing, and while they wait outside her tomb, they see Lucy appear holding a child, her mouth covered in blood. Lucy's expression is completely changed - it's demonic, evil, and she tries to seduce Arthur but Van Helsing intervenes. She returns to her tomb. The next day, the four men return and kill her, returning her body to normal and releasing her soul.

Afterwards, the four men meet with Jon and Mina Harker. Jon was the first to meet Dracula in Transylvania; he escaped, but the ordeal left him nearly broken. Mina was Lucy's best friend who also unknowningly saw Dracula bite Lucy the first time. They all agree to destroy Dracula to prevent him from creating more victims. More events occur, and while the men are busy, they somehow fail to see the obvious signs that Dracula has targeted Mina.

Van Helsing eventually accompanies Mina to Transyvlania, and the other men go after Dracula himself. At Dracula's castle, Van Helsing stakes the three vampire sisters and takes appropriate steps to prevent Dracula from returning to the lair. Van Helsing and Mina meet up with the others, and in the final few pages, Harker and Morris manage to kill Dracula, although Morris dies. Mina goes back to normal, Dracula is no more, and everyone is happy.

It seems a little odd that Integra is a descendent of Van Helsing, considering he's a widower and his son died before reaching manhood. (He tells Seward that he loves Holmwood because Holmwood looks exactly like his dead son would have.) But, then again, Hellsing is only inspired by Dracula. Furthermore, apparently the character whom Integra is supposed to represent from Dracula is actually Mina Harker.