Question

1- Patients with sickle-cell disease and those with sickle-cell trait differ greatly in clinical presentation. List at least two features in clinical presentation, and explain why they differ.

2- Other than hemoglobin S, name two abnormal hemoglobins that produce a positive sickle solubility test. Explain how they could be differentiated from HbS.

3- Explain how methemoglobin is formed, and how its presence impacts oxygen delivery. Be sure to include oxygen affinity in your answer.

4- How is methemoglobin detected in the laboratory?

5- A patient has a positive sickle solubility test. Further investigation reveals hemoglobin of 8.5 g/dL. What can be done to confirm these findings? Explain your answer.

Answer 1

1.patient having sickle cell trait there may be no any symptoms seen in patients while patient having sickle cell disease those having more symptoms like arthritis, severe pain, joint pain, low blood Oxygen so breathlessness, hypoxia and some time sickle cell crisis can be seen in patient and sickle cell disease is life threatening for person .

Sickle cell trait is known as carrier. When it develops complications that may result in sickle cell disease.

Difference between sickle cell disease and sickle cell trait:

Sickle cell trait have one copy of abnormal hemoglobin gene and one normal hemoglobin gene

Sickle cell disease have two copy of abnormal hemoglobin gene.

2. HbS is known as faulty hemoglobin

HbA is normal hemoglobin but when person have abnormal hemoglobin gene that time HbA convert in HbS. Which cause sickling of red blood cell.

There are other two abnormal hemoglobin than HbS. Those are Hemoglobin C and HgbSC. Sometimes it can not be captured in sickle solubility test but it can be identified by hemoglobin electrophoresis in which use high performance liquid chromatography it detect speed of hemoglobin factors. So it can be differentiated by speed of HbS.

3. Methemoglobin is formed while iron of Hb convert from farrous to farric and this is the gas which elevate in blood can cause deprivation in blood oxygen which is known oxygen affinity.

Because this oxygen deprivation can not be recover or improve by Oxygen therapy .it can be treat by methylene blue and others like vit. C and components transfusion.

4.methenoglobin can be identified in lab by arterial blood gas analysis because elevated level of methemoglobin gives dark chocolate brown color of blood and Normal blood color is fresh bright red so it can be identified through blood gas.

5. When sickle solubility test is positive and Hb is 8.5 there should be chances of sickle cell disease so for comfirm the diagnosis perform haemoglobin electrophoresis and other tests like urine analysis, blood count, X ray chest etc.

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