Dear Karen, 

This is a preliminary report and you should read their next report. In your thesis you quote exactly what is said.  This is not very clear so in case the authors are still alive you should ask them. Seven out of 278 of these patients with positive results were considered to have AIP and two to have PCT ??

A total of 7,085 tests were made on 1,774 patients,

yielding four patients with positive results to tests

for porphobilinogen, 270 with excess porphyrins, and

an additional four with both porphyrins and porphobilinogen.

There were 4 patients who showed positive results to

screening for porphobilinogen, 270 patients with excess

porphyrins in the urine, and an additional 4 patients

with both porphyrins and por1phobilinogen.

Seven of these patients with positive results were

considered to have AIP and two to have PCT. There

were, in addition, 268 patients who had excess urinary

porphyrins but no evidence of PCT. The significance of

this will be discussed later. Because it was known that

we were interested in this disease, other known or suspected

cases were referred to us during the ·survey, so

that we have records of 35 cases of AIP and 42 cases

of PCT. These will be discussed in the second article.

The main finding of this series is that AIP and PCT

are rare diseases, even in a survey using acute psychiatric

wards which may provide the most fruitful catchment

areas. 

The most interesting finding was the considerable

number (268) of patients showing excess urinary porphyrins

but in whom there was no evidence of PCT.

These patients were almost all alcoholics, and the positive

test results occurred early in their stay in hospital,

after they had suffered severe liver assault by alcohol

in the preceding weeks. There are three possibilities they

may be people with no association with 1porphyria

who excrete porphyrins purely because of liver damage.

Secondly, they may be abnormal in having a fault (likely

to be a genetically controlled enzyme defect) which does

not allow their physiological processes to cope with

excess porphyrin production. Thirdly, and ,perhaps most

likely, they may have a genetically determined enzyme

fault and be the future sufferers of PCT, in whom skin

lesions will develop with the passage of time and continued

consumption of large amounts of alcohol. This

possibility will also be discussed in more detail in a

second paper.

1) There were a total of 1774 patients in the survey

2) 4 patients had raised urinary porphobilinogen levels (call it group PBL)

3) 270 patients had raised urinary porphyrin levels (call it group POR)

4) 4 patients had both raised (call it group BOTH)

5) 1774-278=1496 did not have raised levels (call it group NONE)

6) In the 278 patients with raised levels, 7 had AIP (clinically) and 2 had PCT (clinically), but we are not told from which of the above groups each of them came from.

7) we are told that 268 patients from group POR did not have PCT, so presumably 2 did have PCT (as opposed  to AIP)

8) 268 in group POR had alcohol problems, and the authors give three reasons as to why this group had  raised porphyrin levels

So, this survey shows that porphyria is rare  in psychiatric inpatients with a point prevalence of 9/1774 (0.5%) in this survey. The chance of porphyria when there was a positive test result was 9/278 (3.2%, which is the sensitivity of the test ), and the chance of not having porphyria if the test was negative was 1496/1496 (100%, ie the specificity of the test). This survey showed that other factors can raise urinary porphyrin levels.

Excellent answers...so what can I add?

A "case study":  THE MADNESS OF KING GEORGE

He probably had acute porphyria

Article Porphyrins: One Ring in the Colors of Life

More re: King George III; some speculate that he had bipolar disorder; but according to most sources, he had acute intermittent porphyria

Porphyria can cause neurological symptoms due to disruption of oxygen transport to the brain.   Lead poisoning is among the neurotoxicant exposures that can disrupt heme biosynthesis and thus, this should be considered in the differential diagnosis of acute porphyria.   James Dyck has written an excellent review article on this topic.

http://www.porphyrie.net/wp-content/uploads/2015/07/Dyck_2015.pdf

 Thank you all for taking the time to respond and reference.