Polly: Sudhir Gupta, MD, a prominent immunologist, gave a lecture at the DAN! 2000 Conference on the immune system in autism. Here are some notes from that lecture. In a preliminary trial of immunoglobulins taken intravenously, some of the autistic recipients improved significantly. One of the immunoglobulins, called IgA, is of particular interest. IgA is the most predominant type of antibody that is found covering the gut mucosa, and IgA is low or absent in a fair number of autistic individuals. IgA keeps toxins and bacteria from binding to the cells that line the intestines. Without enough IgA, the intestines become inflamed, and the lymphoid tissue in the gut swells. (Andrew Wakefield found lymphoid nodular hyperplasia in the autistic children he examined. Other researchers have found this in ADD children too. The changes in the gut are similar to, but not exactly like Crohns and colitis. )
IgA is also important because it lines the mucosa of the lungs and urinary tract and protects these from infections and allergens. The good news is that IgA does not need to be given intravenously. It can be given orally or intranasally. The oral IgA has been used in Europe to treat multiple sclerosis and various diseases. Unfortunately, it is not currently available in the US. Dr. Gupta will be working on getting it approved for some trials here.
One source of immunoglobulins is colostrum, or mother’s first milk. The IgA in colostrum helps the correct bacteria get established and prevents infection by viruses. However, colostrum from cows will not be as effective as human colostrum in fighting disease because the cows have not been exposed to the same bacteria and viruses that we have. Yet there is enough of an overlap that these colostrum supplements may benefit some people. Kirkman Labs carries a casein free colostrum. I have spoken with people who find very big differences in the effectiveness of different brands of colostrum. The most effective colostrums are made from unadulterated first milkings. Typical doses are 3,000 to 4,000 mg per day, or usually 6 to 8 capsules for an adult. The capsules are best administered by opening them up and rubbing them on the inside of the mouth. (Lactoferrin should be administered this way too.) The colostrum should be split into two doses per day. If interested, this is a very good small book on colostrum, Colostrum: Mother Nature’s Healthy Hope for Autism through Nutrition The Health Forum—Book 5 32 Alternative for Every Generation by Lance Wright, MD. 
One of the mothers at the conference mentioned that music therapy can increase IgA production. See http://www.MusicTheraphy.org or phone (301) 589-3300. Bifidobacterium longum, a probiotic bacteria, increases IgA.  So does the Bb-12 (lactis) strain of Bifidobacterium and the soil-based bacteria called B. Subtilis.  Egg yolks contain IgA, and light cooking will not destroy it. If appropriate, undenatured whey will provide IgA. The amino acid glutamine will increase secretory IgA. Natural progesterone increases IgA. Avoid omega-6 oils because rats given omega-6 fatty acids produce less IgA.  (Omega-6 oils are high in most seed oils like corn, safflower, soybean and cottonseed.)
Jock posted these two links to articles about IgA deficiency and testing. The first is from the Jeffry Modell Foundation and the National Primary Immunodeficiency Resource Center.
The next article is from a laboratory, Diagnos- Techs, Inc. in Washington. This lab does testing for IgA, phone (800) 878-3787.
Deficiencies of IgA can be caused by exposure to Rubella, protozoan infection, cytomegalavirus (CMV) or the drugs penicillamine or the antiepileptic drug Dilantin. Genetics may also cause an IgA deficiency. Candida Albicans secretes an enzyme that breaks down IgA and also albumin, collagen, keratin and hemoglobin. 
Tumor Necrosis Factor
Polly: High levels of Tumor Necrosis Factor (TNF) down-regulate the production of glutathione and decrease the blood flow to the brain’s cerebrum and to the extremities. When there is inflammation in the gut, you will also find increased production of TNF. Lowering TNF seems to reduce the inflammation. (The anti-TNF-alpha drug Remicade is presently used on an experimental basis to treat the inflammation in Crohns disease.) Coconut oil and fish oil can lower TNF.  The DPP IV enzyme will degrade (lower) TNF.  Glycine can lower TNF. Serotonin will raise TNF.  Just the DNA from probiotic bacteria lowers TNF. Magnesium will help keep TNF under control.