The porphyrin pathway: the final common pathway?

When I was learning pathology a wise and knowledgeable mentor described a final common pathway that allows many diseases to overlap in their presentation. This pathway was never identified for it was unknown. Recent books by physicians have suggested that maintaining body balance and/or treatment by a substance could halt or repair damage caused by a wide array of diseases, once again suggesting a common thread amongst diseases. Again no mention was made regarding what was this common denominator. I have been interested in people who have more than one disease, feeling that there must be a link. My interest in the porphyrin pathway has strengthened that impression. Since finding Doss's list of diseases having porphyrin abnormalities unrelated to a porphyria, I have worked on models that would allow me to show a way where porphyrin abnormalities may be a part of the final common pathway for all disease. I have finally decided that a spider's web is that model. The following discussion will attempt to demonstrate that this hypothesis could be true.

Porphyria and chemicals

Porphyria is a genetic family of diseases that is most frequently described as neuropsychiatric or toxogenetic. It is well known to be initiated by drugs, infections, heavy metals, hormones, chemicals and fasting. There are extensive lists of drugs that have been known to cause attacks. Others are thought to be likely to cause attacks on the basis of animal studies or in vitro studies. It has become obvious that lists of chemicals capable of causing illness in porphyrics are sorely lacking. Chemicals that have the same base as drugs that are labeled in the PDR (Physicians Desk Reference) as porphyrogenic have no such labeling in their MSDS (Material Safety Data Sheet). This article is intended to point out why porphyria needs to be considered when illness occurs after chemical exposure. The capability of testing enzymes in the porphyrin pathway allows us to evaluate these patients more thoroughly, for we are now aware that the standard measures for recognizing these diseases are often inadequate. Three examples where illness has occurred after environmental exposure to chemicals will serve as illustrations. One, a documented porphyria, is the Turkish porphyria. The other two are not yet documented as porphyria, but may be some day. One is Agent Orange which caused illness in Vietnam, and the other is exposure to unknown sources of what has been named the Gulf War syndrome.

An association of fibromyalgia with primary Sjögren's syndrome: a prospective study of 72 patients

OBJECTIVE

Fibromyalgia patients often describe the presence of dry eyes and dry mouth. Conversely there is an increasing recognition that many patients with Sjögren's syndrome (SS) have fibromyalgia (FM). We decided to investigate this association.

METHODS

Seventy-two patients with FM were screened with a Schirmer's test. All patients with an abnormal test had a minor salivary gland biopsy.

RESULTS

Thirty-eight percent (n = 28) had a Schirmer's test of < 15 mm wetting at 5 minutes, however sicca symptoms were noted in only 19% of patients. Salivary gland biopsy in these 28 patients showed a focus score of > or = 1 in 5; a positive antinuclear antibody test (ANA) was found in 4, a positive rheumatoid factor in 3 and anti-SSA SSB antibodies in 2. Another 8 patients had abnormal salivary gland lymphocytic foci, but there were < 50 cells or the density was < 1 focus/4 mm2; all 8 of these patients had a positive ANA. None of these patients have developed systemic features of SS over a 6 year period of followup.

CONCLUSION

There is a subgroup of patients presenting with FM who, on further testing, have findings consistent with primary SS. The prevalence of this association was 6.9% for probable SS and 11% for possible SS. These figures are probably an overestimation due to tertiary center referral bias. The etiologic and management implications of these observations are unclear.

Fatigue syndromes revisited: the possible role of porphyrins

The author sees many patients with chronic oral problems of unknown etiology. It has been noticed that many of these patients also have complex medical histories. Fatigue and pain are two of the most common features observed. Some, but not all, also have other definitive medical diagnoses. Those patients with appropriate symptoms have been tested for porphyrins and porphyrin enzyme activity. Advances in molecular biology have led to the availability of a number of porphyrin enzymes for routine testing. The results are interesting and suggest abnormal porphyrin metabolism may be more prevalent than is currently thought.

Hereditary coproporphyria

Hereditary coproporphyria is a rarely diagnosed disease and is one of the acute porphyrias. The classic mental, neurological and abdominal symptoms are often observed, but there appear to be atypical clinical features and laboratory findings that may lead to underdiagnosis. In an oral stomatology practice, a group of patients having oral conditions with unknown pathophysiology and multiple systemic complaints were evaluated for porphyrin abnormalities. Blood enzymes, urine and stool porphyrin panels were usually run. A large number of the patients had the clinical symptomatology and porphyrin abnormalities classically found in hereditary coproporphyria.

Fatigue syndromes: new thoughts and reinterpretation of previous data

Recently, the author has identified 19 patients who have complained of marked fatigue that had abnormal responses to copper test bracelets or necklaces. At this time, 8 have been shown to have at least one enzyme deficiency in the heme pathway. These patients have been diagnosed with multiple sclerosis, chronic fatigue syndrome and other non-specific diagnoses. A lengthy but still limited review of the literature was performed regarding the following conditions: multiple sclerosis (MS), hepatic porphyria (HP), chronic fatigue syndrome (CFS) and paralytic polio (PP). The text will focus on similar epidemiologies, laboratory findings and clinical courses. Copper as a common but not unique etiologic agent will be discussed; as will the heme pathway, a biologic process that may be disordered in all.