Dr John Warren
Around the age of 50, I started to get very tired, and my memory seemed strangely unreliable. I would see a patient whom I had seen a month or two before, and there was my handwriting in the notes, but I had no recollection of the previous consultation. This was scary. At the same time I developed chronic diarrhoea, 8-10 times a day. And my mouth was full of aphthous ulcers, and the tip of my tongue was sore. I began to think I might have some serious condition, but had no idea what it was. Once, after I had climbed four flights of stairs in the hospital one of the junior doctors I worked with asked if I had checked my haemoglobin recently, and, stupidly, I took no notice. Every day when I got home from the hospital I just went to bed and slept most of the evening.
I was reluctant to consult a colleague and say ‘I feel tired all the time’, as I know this is a symptom most of my colleagues dread to hear from a patient. Likewise, I wasn’t keen on seeing a gastroenterologist, as I knew this would inevitably result in unpleasant endoscopic examination of my guts, particularly not a nice prospect in the department where I myself worked. I began to think I must have some fatal illness, and I just would struggle on until I couldn’t go on anymore. In retrospect, I think I was depressed, and my judgement must have been impaired. I went on a skiing holiday in the Alps, thinking a holiday would do me good, but felt even worse at the high altitude and spent most of the week in bed.
I had been a blood donor, and was called to give blood every 6 months. The call came, and even though I felt so ill, I went along. They carried out the customary finger prick blood test, and then, to my surprise, refused to take my blood, as the haemoglobin was low. That galvanised me, and I immediately wrote out a request for a full blood count for myself, and went round to the pathology laboratory. Within 3 hours I had the haematologist on the phone to me, to say that there was something very wrong with my blood. I was anaemic, and the red cells were all funny shapes and sizes, some big and some small. The haematologist arranged a check of my iron, B12 and folate. The results showed a very low B12, and very low iron, with normal folate. I immediately prescribed B12 injections and iron tablets for myself.
Following this I contacted a gastroenterologist at a neighbouring hospital and asked if he would investigate my problem. I had my autoantibodies done, and I had antibodies to intrinsic factor, gastric parietal cells and thyroid. Thyroid function showed an abnormal result indicating subclinical hypothyroidism. I had a gastroscopy, and this showed gastric atrophy. I also had a colonoscopy, and this showed no source of bleeding to account for the iron deficiency. Biopsies of the terminal ileum showed a non-specific ileitis, insufficient to support a diagnosis of Crohn’s disease. Tests for coeliac disease were negative.
With B12 treatment my memory and fatigue gradually recovered. I reckoned it took 2 years for me to regain my full strength and joie de vivre, but my wife insists it took 3 years. I reckon now, as I approach 80, my cognitive function is as good as anyone could expect.
So it became clear that I had pernicious anaemia, associated with autoimmune thyroid disease and alopecia. Initially, oral iron supplements made the diarrhoea even worse, but after 2 or 3 months I was able to stop them, once the blood count and iron levels had normalised. Naturally I carried on injecting myself with intramuscular hydroxocobalamin 1000 microgrammes. I tried to reduce the frequency of the injections to 3 monthly, as recommended. But I found this was impossible without recurrence of symptoms. About 4-6 weeks after the dose, mouth ulcers, sore tongue and diarrhoea would return, and so I settled on monthly dosage, which I have maintained for the last 30 years since diagnosis. Since I have been on B12 my iron levels have remained in the normal range.
The alopecia has become universal and irreversible now. I continued checking my thyroid function from time to time and the tests remained slightly abnormal, so after 2 or 3 years, and discussion with an endocrinologist, I started taking thyroxine tablets, adjusting the dose to achieve normal thyroid blood tests.
There are some interesting lessons arising from my history. Prior to diagnosis I had not been aware of the impact B12 deficiency may have on the gut. It is mentioned in small print in some textbooks, but I suspect most doctors would not be aware of it. It seems that either the B12 deficiency caused a failure of iron absorption, or it resulted from lack of acid secretion in the stomach, which aids iron absorption. In my case, it seems that a direct effect of B12 deficiency was mainly responsible, since B12 replacement treatment has prevented further episodes of iron deficiency.
The fact that some patients with PA need much more frequent B12 dosage than others remains unexplained, and some of my colleagues believe that patients who request more frequent dosage are making a nuisance of themselves. But who would demand more frequent intramuscular injections than their doctor advised, unless there was a massive benefit from it? One might have expected patients on regular IM injections to abscond.
The clustering of autoimmune diseases has been noticed for many years. In the 1960’s the term ‘thyrogastric syndrome’ was given to the association of autoimmune thyroid disease and chronic autoimmune gastritis (which leads to malabsorption of vitamin B12, and failure of hydrochloric acid secretion by the stomach). More recently this association has been included in ‘polyglandular autoimmune syndrome type IIIb’. The thyroid disorder is the most frequent autoimmune disease, and has been found to be associated with gastric disorders in 10-40% of patients. The other way on, some 40% of patients with autoimmune gastritis are found to have thyroid disorder. So far as I know no one has explained what triggers the onset of these autoimmune diseases. Clearly some patients inherit a genetic tendency to get them. But not all patients with such a tendency develop disease. My mother (whose father and daughter both developed type I diabetes) lived to 96, and had thyroid and gastric parietal cell antibodies, but she never developed clinical pernicious anaemia, thyroid disorder, or any other autoimmune disease.