Further, no one is certain that the immune disorder can be reversed. Many patients have survived a bout of pneumonia or other illness, only to succumb to another or to go on to develop Kaposi's sarcoma or some other fatal cancer. 'Natural' Immunity Suppressor

GRID resembles the failures of the immunological system that complicate the treatment of many chronic disorders with steroid and other drugs that suppress the immune system. The same problem occurs among recipients of transplanted kidneys and other organs who take the immunosuppressive drugs to help prevent rejection of the organ. With immunity suppressed, the body becomes vulnerable to a variety of problems, chiefly infections by organisms that otherwise rarely cause disease.

GRID, however, is the first naturally occurring outbreak of immune suppression to affect a community of free-living people, in contrast, for example,to an epidemic in a hospital. The degree of immunological suppression is extraordinary, far greater than usually observed in patients treated with immunosuppressive drugs, according to articles in medical journals and interviews with experts.

Those experts are now reporting finding a wider range of disorders than were associated with GRID when it first came to public attention last summer. These include eye damage, lupus, I.T.P. (idiopathic thrombocytopenic purpura), certain types of anemia, and other cancers, including Burkitt's lymphoma and cancers of the tongue and anus.

Doctors are also seeing many cases of a generalized lymph gland swelling throughout the body, together with weight loss, fever and thrush, a fungal infection often found in the mouth and throat.

So far, epidemiologists have found no evidence that the condition is spread from person to person like influenza or measles. Therefore, they say, the general public need not fear an epidemic. Many Causes Are Likely

Rather, Dr. Arthur S. Levine of the National Cancer Institute said, development of the syndrome seems to result from an accumulation of risk factors. Most experts say that if there is an infectious cause, it is not a single organism, but an organism acting together with another factor or factors, perhaps a drug.