Recognising a blood-test pattern is not the same as identifying its cause. A cholestatic panel can direct the investigation without proving a particular obstruction. A monoclonal protein can be important without automatically establishing myeloma.
This blood test interpretation quiz uses six original fictional panels. It asks what the results suggest and what remains uncertain, rather than focusing on the immediate management decisions covered in the separate abnormal blood results quiz.
All patients described are currently clinically stable unless otherwise stated. Reference intervals are illustrative adult intervals, not universal cut-offs. Use the actual laboratory's method, units and relevant population when interpreting a real report.
For each panel, write a pattern, one possible explanation and one piece of information that could support or challenge it.
The six panels
1. The relative rise matters
A 56-year-old has persistent itching and newly recognised jaundice. There is no current fever, acute severe abdominal pain or circulatory instability. No cause has yet been established.
| Test | Result | Illustrative interval |
|---|---|---|
| ALT | 80 U/L | 5-40 U/L |
| ALP | 440 U/L | 30-120 U/L |
| GGT | 300 U/L | 5-60 U/L |
| Total bilirubin | 60 micromol/L | 3-21 micromol/L |
Question: Is the dominant pattern cholestatic or predominantly hepatocellular? Does it prove an obstructing gallstone?
2. The same enzyme, a different surrounding panel
An adult recovering from a fracture has an unexpectedly raised ALP. They have no jaundice or new hepatobiliary symptoms.
| Test | Result | Illustrative interval |
|---|---|---|
| ALP | 280 U/L | 30-120 U/L |
| GGT | 22 U/L | 5-60 U/L |
| ALT | 24 U/L | 5-40 U/L |
| Total bilirubin | 11 micromol/L | 3-21 micromol/L |
Question: Why should the ALP not automatically be assigned to the liver? What would make the proposed bone-related explanation more convincing?
3. Iron is low, but storage and transport markers do not tell the usual story
A 58-year-old with clinically active rheumatoid arthritis reports fatigue. No recent overt bleeding is described, although the wider history has not yet been completed.
| Test | Result | Illustrative interval |
|---|---|---|
| Haemoglobin | 104 g/L | 120-160 g/L |
| MCV | 86 fL | 80-100 fL |
| Serum iron | 4 micromol/L | 10-30 micromol/L |
| Total iron-binding capacity | 35 micromol/L | 45-72 micromol/L |
| Ferritin | 250 micrograms/L | 15-150 micrograms/L |
| CRP | 45 mg/L | Less than 5 mg/L |
Question: Which process fits the relationship between iron, binding capacity, ferritin and inflammation? Does the ferritin completely exclude coexisting iron deficiency?
4. Fractionate the bilirubin
A well 29-year-old has an intermittent mild bilirubin elevation documented on previous tests. There is no anaemia or current systemic illness. The current blood film and haemolysis markers have not suggested red-cell destruction.
| Test | Result | Illustrative interval |
|---|---|---|
| Total bilirubin | 40 micromol/L | 3-21 micromol/L |
| Direct bilirubin | 5 micromol/L | Less than 7 micromol/L |
| ALT | 20 U/L | 5-40 U/L |
| ALP | 74 U/L | 30-120 U/L |
| Haemoglobin | 146 g/L | 130-180 g/L |
Question: Which bilirubin fraction predominates? What relatively common explanation is compatible with the supplied context, without being established by the number alone?
5. The thyroid values disagree only if you ignore the feedback system
A nonpregnant adult has had a similar result on two appropriately timed measurements. They are not acutely unwell, and the history identifies no thyroid treatment or known assay-interfering supplement.
| Test | Result | Illustrative interval |
|---|---|---|
| TSH | 7.2 mIU/L | 0.4-4.0 mIU/L |
| Free T4 | 14 pmol/L | 10-22 pmol/L |
Question: Name the biochemical pattern. Does the word "subclinical" establish that the patient has no symptoms or that treatment is always required?
6. An additional protein needs a classification, not an automatic cancer label
A stable 70-year-old has an elevated total protein. Subsequent electrophoresis and immunofixation identify an IgG-kappa monoclonal component measured at 8 g/L. No bone symptoms are reported, but assessment is not yet complete.
| Test | Result | Illustrative interval |
|---|---|---|
| Total protein | 88 g/L | 60-80 g/L |
| Albumin | 40 g/L | 35-50 g/L |
| Haemoglobin | 135 g/L | 120-160 g/L |
| Creatinine | 82 micromol/L | 45-90 micromol/L |
| Adjusted calcium | 2.35 mmol/L | 2.20-2.60 mmol/L |
Question: What has been demonstrated? Why do these results alone establish neither myeloma nor the complete criteria for MGUS?
Explained answers
1. A predominantly cholestatic pattern
The ALP and GGT rise disproportionately relative to ALT, supporting a cholestatic pattern. A useful first observation is the relationship to each test's upper reference limit, not a direct comparison of the raw numbers from different assays.
ARUP Consult's liver-test guidance distinguishes cholestatic, hepatocellular and mixed patterns and identifies several possible hepatobiliary causes.
The panel does not establish a gallstone, the site of an obstruction or whether the process is intrahepatic. Medication exposure, the clinical history and appropriate imaging or additional tests can refine that question.
The supplied absence of acute instability keeps this an interpretation exercise; it should not be used to imply that fever or deterioration could be ignored in a real patient.
In clinical connections, a similar task is to identify the relationship explaining a set of concepts rather than simply notice that they are all abnormal or medical.
2. Consider a non-hepatic ALP source
ALP has important sources outside the liver, including bone. Here, the normal GGT and otherwise unremarkable liver panel make a bone contribution plausible in the context of fracture healing.
The AASLD approach to elevated liver enzymes explains the use of GGT when investigating the origin of an ALP elevation.
That is supporting evidence, not proof that the fracture explains the entire result. Review the timing, previous values and other relevant bone or hepatobiliary findings; laboratory advice or isoenzyme testing may help where the source remains unclear.
The mistake would be to label every raised ALP a "liver-function abnormality" and then investigate only within that frame.
3. Iron restriction associated with inflammation
The combination is compatible with anaemia of inflammation: iron availability is reduced, while ferritin is preserved or raised and iron-binding capacity is low.
The ARUP discussion of anaemia of inflammation explains iron sequestration and the possibility of coexisting iron deficiency.
The illustrative transferrin saturation is approximately 4 / 35 x 100 = 11.4%. This is a calculation from the fictional panel, not an additional measured result.
The raised ferritin should not be used as an absolute exclusion of depleted iron stores in an inflammatory setting. The history, trend, renal function and further testing where indicated can change the interpretation.
A low serum iron alone cannot distinguish all these possibilities. The question is how the markers behave together.
4. Predominantly unconjugated hyperbilirubinaemia
The estimated indirect component is 40 - 5 = 35 micromol/L, so the elevation is predominantly unconjugated.
In the supplied setting of an intermittent isolated rise and no evidence of haemolysis, Gilbert's syndrome is compatible with the pattern. The NHS account of Gilbert's syndrome explains the altered processing of bilirubin and the generally mild intermittent presentation.
This is not a rule that every raised bilirubin in a young adult is Gilbert's syndrome. New jaundice, different fractions, abnormal accompanying tests or evidence of haemolysis would reopen the assessment.
The useful first move is fractionation. The total bilirubin says that something is elevated; the relationship between its components helps frame why.
5. A subclinical hypothyroid biochemical pattern
A raised TSH with a free T4 within the relevant interval is the biochemical pattern termed subclinical hypothyroidism.
ARUP's hypothyroidism guidance distinguishes it from overt primary hypothyroidism and notes that interpretation depends on appropriate reference intervals and context.
The term is not a declaration that the patient cannot have symptoms. Nor does recognising the pattern settle whether treatment is appropriate for this individual.
The persistence, age, symptoms, antibody status, medicines and relevant clinical circumstances can inform the subsequent assessment. This question stops at interpretation rather than prescribing a universal response to a TSH of 7.2.
The important relationship is that the pituitary signal is increased while circulating free T4 remains within the stated interval.
6. A monoclonal gammopathy has been identified
The electrophoresis and immunofixation demonstrate a monoclonal immunoglobulin component. They do not, by themselves, classify the complete underlying disorder.
The ARUP plasma-cell-disorder guidance describes how monoclonal-protein testing fits alongside free light chains and the wider assessment of possible plasma-cell disease.
The reassuring values supplied are relevant, but no single small panel establishes that every myeloma-defining feature or other clinically important monoclonal-protein disorder has been excluded. Conversely, finding a monoclonal component is not an automatic diagnosis of myeloma.
Further assessment should determine the appropriate classification and follow-up. Whether marrow examination or imaging is needed depends on that evaluation rather than an instruction to perform the same investigation in every person.
What changed between the first two panels?
Both had a raised ALP, but the surrounding evidence changed.
In panel 1, GGT and bilirubin rose alongside it, supporting a hepatobiliary interpretation. In panel 2, GGT and the other supplied liver tests were unremarkable, and the history offered a plausible bone-related contribution.
This paired comparison illustrates the purpose of pattern recognition. The same test name does not always identify the same process.
A useful review question is therefore not simply "what causes a high ALP?" but "which accompanying findings help identify its source in this patient?" That gives a more precise target for further reading.
Separate three levels of conclusion
A result describes a measurement. A pattern describes a relationship between measurements. A diagnosis explains that relationship in a person.
Those levels can be close, but they should not be silently collapsed. "Monoclonal component detected" is a different conclusion from "myeloma established". "Cholestatic pattern" is different from "stone obstructing the common bile duct".
For teaching, ask participants to state which level they have reached. Then ask what additional information would justify moving to the next one.
The management-focused blood-results quiz explores the separate question of what action should follow a result. It uses different panels, including more immediately concerning presentations.
Take one uncertainty into the next activity
Review the panel in which you jumped most quickly from a number to a diagnosis. Write the missing evidence as a question rather than a broad instruction to revise laboratory medicine.
The next activity might be reading the relevant source, discussing the case with a colleague or trying a new association puzzle. clinical connections offers mixed clinical science, not a promise that today's board will contain laboratory results.
Frequently asked questions
Are these laboratory ranges suitable for every patient?
No. They are illustrative adult intervals. Actual interpretation depends on the laboratory method, units, age, pregnancy status and other relevant context.
Does recognising the correct pattern establish its cause?
Not necessarily. A pattern can guide investigation while leaving several plausible causes or classifications unresolved.
Is this the same quiz as the abnormal blood results management article?
No. These are different original panels focused on interpretation. The companion article asks about urgency and the next management action.
Explore another set of relationships in today's clinical connections puzzle