Immunoproliferative small intestinal disease: Description, Causes and Risk Factors:
Immunoproliferative small intestinal disease (IPSID) is a pre-lymphomatous process that is unusual among persons native to the United States. It has distinct epidemiological and histological features and commonly develops into a frank lymphoma that extends throughout the small intestinal subepithelial tissues from the lamina propria to the muscular layers and eventually to the mesenteric nodes.
The etiology of this disease remains unclear, although various parasitic, genetic, and toxic mechanisms have been proposed. Environmental factors appear to be important, because there is a significant association with poor hygienic standards, endemic parasitic infestation, and infantile infectious enteritis. It has been postulated that chronic stimulation from bacterial or parasitic antigenic particles may cause an overproliferation of the intestinal lymphoid system, eventually developing into a monoclonal proliferation once frank lymphoma occurs. Environmental exposures early in life may be particularly important; for instance, IPSID is less prevalent in Jews born in Israel than in Jews born in Africa who had immigrated later to Israel, where living standards are higher. On the other hand, monoclonal gene rearrangements in early disease suggest to some that IPSID is neoplastic from the outset. Given that Immunoproliferative small intestinal disease is relatively uncommon despite the extensive bacterial and parasitic exposure in underdeveloped countries, genetic factors are likely to play a role as well. This is supported by a possible association between IPSID and human leukocyte antigen types Aw19, B12, and A9, as well as with blood group B. One study has shown high concordance rates of this condition among blood relatives, even when living apart. In addition, unusually high levels of serum alkaline phosphatase from intestinal sources are found both in patients and in healthy first degree relatives
Stages: The stage A (benign) shows overwhelming plasmacytic infiltrate with only few CD20 positive marginal zone B cells. Stage B (intermediate) is characterized by lymphoid aggregates and variable villous atrophy and atypical large immunoblast like cells. The infiltrate usually extend beyond mucosa. In stage C (malignant) high grade lymphomas of large B-cell type with prominent plasmacytoid differentiation originate in a background of low stage IPSID, which are strong positive for CD20.
IPSID may be a major public health issue in developing countries, where it is more common. With the increasing number of immigrants from the Third World living in the United States.
Patients with IPSID usually present with malabsorption syndrome
, diarrhea, weight loss, and abdominal pain of months to years duration. Features of malnutrition like peripheral edema
, clubbing, or abdominal mass is often evident. The patient also have anemia and vitamin deficiencies.
The diagnosis of IPSID depends on an extensive analysis of the intestinal histology, although radiographic and endoscopic studies may often provide clues. Radiographs reveal a serrated pattern at the edge of mucosal folds, especially in the presence of lymphomatous involvement. Endoscopy often shows a nodular pattern due to diffuse thickening and infiltration of mucosal folds. Diagnosis is confirmed by characteristic findings on peroral biopsy; if positive, a staging exploratory laparotomy is mandatory to examine the mesenteric lymph nodes because of the frequent discrepancies between intestinal and mesenteric lymph nodes with regard to lymphomatous foci. Immunoproliferative small intestinal disease must also be distinguished from celiac sprue, tropical sprue, AIDS enteropathy, and Whipple's disease, because all of these can be associated with villus changes and increased infiltration of the lamina propria with round cells.
On immunohistochemistry, lymphoid cells were positive for leukocyte common antigen (LCA) and CD20while plasma cells were positive for CD79a, CD138, IgA and sometimes for IgG and IgM. SerumIgA levels were also raised in most cases.
Because of the unclear etiology of this illness, therapy has been empirical and only indifferently successful. Some experts approach IPSID as an infectious disease and recommend antibiotics; others regard it as a pre-malignant condition and prefer cancer chemotherapy. Tetracycline has been reported to induce clinical, histological, and immunological remission in up to 40% of patients with pre-lymphomatous Immunoproliferative small intestinal disease.
NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.