Biology of Disease

General treatments include daily ingestion of folate when hemolysis is
significant, and blood transfusions. The symptoms of HE and HS are alleviated
by surgical removal of the spleen (Table 16.6). This increases the time the
defective erythrocytes stay in the circulation to about 80% of that of a normal
erythrocyte.

SUMMARY

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CASE STUDY 16.1

Bethany, a female infant, suffers from recurrent

respiratory infections and presented with clinical

evidence of dietary malabsorption. Her brother and sister

are asymptomatic. She was sent to hospital for a variety

of clinical investigations. After a number of negative tests,

she was subjected to a sweat chloride test. The result is

given below:

Sweat [Cl–] 76.0 mmol dm–3 (Normally less than

30 mmol dm–3)

Questions

(a) Suggest a plausible diagnosis.

(b) Explain how the diagnosis for Bethany was

reached.

(c) How should Bethany’s siblings be investigated?

CASE STUDY 16.2

Janice is an 18-year-old. She was admitted to hospital for

clinical tests following a series of frequent heavy nose

bleeds and extensive bruising following comparatively

minor accident bumps. She also complained of stiff aching

joints and some pains in her long bones. Her erythrocyte

and platelet counts were found to be depressed. There

was some extension of her abdomen. Routine clinical

tests eliminated leukemia. Enzyme assays showed

B glucocerebrosidase activity in leukocytes to be greatly

reduced.

Questions

(a) What is Janice suffering from?

(b) What would be the likely progression of this disease

if untreated?

(c) What treatment would you recommend for Janice?

Before splenectomy After splenectomy

Erythrocyte count x 10–12dm^3 3.1 5.2

Reticulocytes / % 16.0 0.95

[Hemoglobin]/gdm–3 8.5 15.1

Serum [bilirubin] / mmol dm–3 83.0 8.2

Table 16.6Typical hematological data before and after splenectomy in a patient suffering from
hereditary spherocytosis (see Chapter 13)

16.8 Summary

Defects in the plasma membrane or those that surround organelles and
in the cytoskeleton cause a variety of disorders, some of which have been
outlined. Disorders of nucleocytoplasmic transport have been implicated
in a number of diseases, including some cancers. Cystic fibrosis, which is