%0 Journal Article %T Helicobacter pylori Infection and Light Chain Gammopathy %A Jos¨¦ A. Gir¨®n %A Shawn L. Shah %J Journal of Immunology Research %D 2013 %R 10.1155/2013/348562 %X Objective. Helicobacter pylori provokes a host of immune alterations upon colonizing the gastric mucosa. Design. We report 22 individuals with confirmed Helicobacter pylori infection who were also managed for the concurrent elevation of immunoglobulin free light chain (kappa and lambda) levels. Result. Of the 22 patients, 15 patients (68.2%) had elevated free light chain levels: 6 patients (40%) had only kappa chain elevation, 2 patients (13.3%) had only lambda chain elevation, and 7 patients (46.7%) had both kappa and lambda chain elevation. Twenty out of the 22 patients (90.9%) were microbiologically confirmed cured with 3 patients being lost to follow-up for repeat levels. Of the 3 patients who were lost to follow-up, 1 patient had only kappa chain elevation, 1 patient had only lambda chain elevation, and 1 patient had both kappa and lambda chain elevation. For those who were cured (19 patients), 5 patients with kappa elevation had normalized values, 4 patients with lambda elevation had normalized values, and 2 patients with combined kappa and lambda elevation had normalized values. For 6 out of the 19 patients, the light chain levels remained elevated. Conclusion. We speculate that the Helicobacter pylori infection disrupts the immunoglobulin system with potential implications being discussed below. 1. Introduction Helicobacter pylori is one of the most pervasive bacterial pathogens worldwide and is associated with an increased risk of gastritis, gastric and duodenal ulcers, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue (MALT) lymphoma [1, 2]. Indeed, it has been nearly three decades since the Australian physicians Warren and Marshall first isolated the pathogen and elucidated its association with gastric and duodenal ulcers as well as gastritis, leading to significant research towards the treatment of these gastrointestinal disorders [3]. While the incidence of the H. pylori infection varies largely by socioeconomic status, geographic region, age, and race, approximately one-half of the world¡¯s population has been estimated to be infected, with the prevalence ranging from 30 to 40 percent in the United States [4, 5]. In fact, in the United States, the prevalence increases from less than 20% at 20 years of age to nearly 50% at 50 years of age [6]. Today, with the advent of the newer concomitant quadruple therapy, the eradication of H. pylori has experienced success rates greater than 90 percent [7, 8]. In a patient with light chain deposition disease, a transient increase in light chain levels was observed upon H. pylori %U http://www.hindawi.com/journals/jir/2013/348562/