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The prevalence of the disease is unknown but most cases have been from North African and Middle Eastern/Mediterranean countries and have been associated with poor sanitation. There have been more than 400 cases reported in the world literature.

Alpha-HCD has a predilection for young age groups (20-30 years). Patients present with symptoms of malabsorption. Diarrhea, weight loss and abdominal pain are common. Parasitic infections are often present. Infiltration of the jejunal mucosa with plasmacytoid cells is the most frequent pathologic feature. Immunoblastic lymphoma occurs as the disease progresses.

The exact cause of alpha-HCD is unknown. The lymphoplasmacytic infiltration of the intestinal mucosa is felt to be a response of the alimentary tract immune system to prolonged luminal antigenic stimulation by intestinal organisms.

The diagnosis of alpha-HCD is based on identification of free alpha-heavy chains without associated light chains. Truncated alpha-heavy chains can be detected in biological fluids (serum, urine, jejunal secretions) by immunoelectrophoresis, immunoselection, or immunofixation.

Alpha-HCD disease must be differentiated from non-Hodgkin lymphoma (NHL; see this term), although this is an uncommon diagnosis in the age range typical of alpha-HCD. Other causes of small bowel malabsorption need to be considered, especially celiac disease (see this term).

Initial treatment consists of eradication of any concurrent infection (e.g., parasites, viruses, Helicobacter pylori, Campylobacter jejuni) with appropriate antibiotics. For patients with symptomatic disease not responding adequately to antibiotics, chemotherapy similar to that used to treat NHL is recommended. Surgical resection is sometimes needed when bulky masses are present.

The disease course of alpha-HCD is variable and long-term prognosis of the disease is imprecise. Without antibiotics and chemotherapy the disease progresses rapidly and prognosis is poor.