VALUE OF IMMUNOLOGICAL TESTING AS AGAINST THE HISTOPATHOLOGICAL AND BACTERIOLOGICAL TESTS IN MAKING A DIAGNOSIS IN PRIVATE PRACTICE
O P Kapoor
Ex. Hon. Visiting Physician, Jaslok Hospital and Bombay Hospital, Mumbai,
Ex. Hon. Prof. of Medicine, Grant Medical College and JJ Hospital, Mumbai 400 008.
In the past practitioners made a diagnosis of tuberculosis by a histopathological report showing the presence of granuloma (off and on with caseation). Quite often this report is wrong. Such histopathological pictures can be produced by a number of other conditions like fungi, e.g. patient having a systemic disorder with all the symptoms of tuberculosis and involvement of viscera like liver, spleen, intestines or the mucous membranes, could be due to histoplasmosis which is now 100% curable with itraconazole provided the diagnosis is made in time before the patient dies of complications and involvement of the brain. Such differential diagnosis could be made only if the histopathologists start staining their slides to demonstrate the bacteria or the fungi with special stains. Thus came the help of microbiological diagnosis where the doctors could be told whether the bacteria or fungus or the protozoa were responsible for the illness. Then the practitioners went through the phase when too much reliance was put on the microbiology.
With the emergence of the molecular laboratories in the pathology departments of many hospitals, immunological method of diagnosis has surpassed the other diagnosis. A very good example is of our chest patients in whom I suspect aspergillosis as the cause of lung fibrosis. Many practitioners will confirm this diagnosis by demonstrating aspergillus in the sputum or in secretions collected by nebuliser or a broncho alveolar aspiration.
Unfortunately, even after all these costly and tedious invasive investigations, the demonstration of the fungus does not confirm the diagnosis because it could be present in many normal persons without producing any disease. It is only by demonstrating IgM antibodies against aspergillosis that one can diagnose that the fibrosis is due to aspergillosis and then give the modern anti-fungal drugs to these patients for a complete cure.
Thus years back the diagnosis was made by clinicians at the bed side. Then came the days of X-rays and other radiological procedures when the final diagnosis was pronounced (right or wrong). This was followed by emergence of new imaging techniques like sonography, scanning etc. The diagnosis was further improved by advances in histopathology and microbiology. Time has now come when the G. Ps should take full advantage of the role of immunological testing in the accurate diagnosis of a disease. This could be either done by doing a blood test or by employing immuno histochemistry testing of a tissue supplied by a surgeon or a gynaecologist or a super specialist to a histopathologist.