Studies in the Biology of Disease 2016-17 – Coursework Assignment 1
Integrated case study: Mariana Basescu
The aim of the case study is to introduce you to the investigative nature of Biomedical Science and to show how the individual disciplines integrate and aid the differential diagnosis. Your task is to interpret the data utilizing information learned during the module backed up by information gleaned from your reading around the topic to make a diagnosis and answer specific questions set.
You will need to think about the importance of the presenting symptoms, the initial results obtained by the GP and any further investigations. You will need to think carefully on the differential diagnosis, how certain results rule out potential diagnosis or narrow the potential possibilities. Having made a diagnosis, you should think about potential treatment options.
The following points are important to help you think about how to approach the case study:
- Ensure you answer all questions asked.
- Use the marks allocated to each question as a guide to how much of your word count to spend on each (1000 words ± 10%).
- Consider all results – ensure you discuss the results relevant to the question asked. Don’t discuss, for example the microbiology results if asked about the haematology results. Make sure you know which tests come under which discipline.
- Put your answers into the context of the case study – Once you have arrived at your diagnosis don’t answer the questions simply from the viewpoint of knowing the result. Demonstrate your understanding of the underlying physiology that has gone awry and you should continually refer to the patient, her presenting symptoms and results of the investigations.
Please hand in your 1000-word write-up with a myuwe coversheet into the coursework box in 1A Coursework Hub before 2pm on Tuesday 6th December.
Mariana Basescu is a 25 year old doctoral student. She has been feeling tired and run down for a couple of weeks and over the last day or so has had a slightly raised temperature. She has lost a little weight recently. She has put her fatigue and weight loss down to the stress of her job and irregular meals whilst on working long days in the laboratory and trying to complete her thesis; however with the raise in temperature she agreed to take her friends advice.
Back in July she had spent a month’s voluntary work in Haiti with the Disasters Emergency Committee (DEC) in the earthquake relief effort. In retrospect she felt the stress from that visit may have contributed to her fatigue and weight loss. She had been inoculated for Diphtheria, Hepatitis A, Tetanus and Typhoid, but was on no other medication, apart from some aspirin in the last couple of days because of the raised temperature. She is a non-smoker and said she drinks moderately. The practice GP did a dipstick test on a urine sample that showed the presence of some protein and leukocyte esterase, so he sent both urine and faeces samples to microbiology.
The initial results were as follows.
Haematology & Biochemistry blood results
|
Investigation |
Result (normal range – female) |
| Red cell count (x 1012/L) | 4.2 (3.8 – 5.8) |
| Haemoglobin (g/L) | 125 (115 – 165) |
| White cell count (x 109/L) | 7.1 (3.6 – 11.0) |
| neutrophils | 3.4 (1.8 – 7.5) |
| lymphocytes | 3.1 (1.0 – 4.0) |
| monocytes | 0.47 (0.2 – 0.8) |
| eosinophils | 0.12 (0.1 – 0.4) |
| basophils | 0.02 (0.02 – 0.1) |
| Platelets (x 109/L) | 176 (140 – 400) |
| Blood Urea (mmol/L) | 3.3 (2.5 – 7.0) |
| Serum creatinine (mol/L) | 85 (70-110) |
| Serum sodium (mmol/L) | 140 (135 – 145) |
| Serum potassium (mmol/L | 3.6 (3.5 – 5.0) |
Microbiology Results
|
Urine: Microscopy |
Faeces: Microsopy |
| WBC <5 per ml | No Cryptosporidium seen |
| RBC <5 per ml | No ova cysts or parasites seen in wet prep |
| Epithelial cells – moderate numbers | No ova cysts or parasites seen in concentrate |
|
Culture |
Faeces: Culture |
| No significant growth | No Salmonella, Shigella, Campylobacter, E. coli O157 or Vibrios isolated |
Mariana returned to her GP one month later, as she was not getting any better. She reported that her urine was now a pale orange colour. The GP’s examination now detected tenderness of lower abdomen and a number of bruises on her legs. On questioning she mentioned that she seemed to bruise very easily at the moment. He requested a further FBC and liver function tests.
Second Haematology and Biochemistry results
|
Investigation |
Result (normal range – female) |
| Red cell count (x 1012/L) | 4.0 (3.8 – 5.8) |
| Haemoglobin (g/L) | 123 (115 – 165) |
| White cell count (x 109/L) | 8.1 (3.6 – 11.0) |
| neutrophils | 2.9 (1.8 – 7.5) |
| lymphocytes | 4.5 (1.0 – 4.0) |
| monocytes | 0.62 (0.2 – 0.8) |
| eosinophils | 0.10 (0.10 – 0.40) |
| basophils | 0.02 (0.02 – 0.1) |
| Platelets (x 109/L) | 138 (140 – 400) |
| Prothombin time (s) | 20 (11 – 14) |
| Activated Partial Thromboplastin Time (s) | 45 (24 – 37) |
| Serum Bilirubin (mol/L) | 50 (≤21) |
| Serum ALP (IU/L) | 300 (≤130) |
| Serum AST (IU/L) | 527 (≤30) |
| Serum ALT (IU/L) | 650 (≤35) |
| Serum albumin (g/L) | 37 (30 – 50) |
On analysis of these haematology & biochemistry results, plus Mariana’s case history, the GP requested a further blood sample be taken and sent for Hepatitis B serology. The results of the serology are shown in the table below.
|
Hepatitis test |
Test result |
| HBsAg | positive |
| Anti-HBc | positive |
| IgM Anti-HBc | borderline |
| Anti-HBs | negative |
ANSWER ALL QUESTIONS
| Question Number | Question | Marks (%) |
| 1 | What infectious diseases have been ruled out in the microbiology results? Give the rationale behind your conclusions. Given that Mariana made no mention of diarrhoea why did the GP send a faeces sample? | 20 |
| 2 | By comparing the laboratory investigations relative to the reference ranges, discuss the possible causes of the altered biochemical findings seen in Mariana’s second set of results | 20 |
| 3 | On that second visit, the GP suspected problems with Mariana’s liver. Explain how impaired liver function could result in the haematological results obtained. | 20 |
| 4 | Discuss the meaning of the serology results, including how you would confirm your diagnosis & determine how infectious Mariana is? What treatments could you recommend to improve her immunity against this virus? | 20 |
| 5a | Describe the microscopic appearance of viral infected liver cells when stained with haematoxylin and eosin (H & E) on a tissue biopsy and give examples of other histological stains that would be useful here including expected results for Mariana. | 10 |
| 5b | What are the long term implications of a chronic viral infection, and what changes would you expect to observe in the liver tissue of a patient with a chronic viral infection? | 10 |
