Acute Renal Infarction Unveiling an Undiagnosed Factor V Leiden Mutation: A Case Report

Breaking News: Acute Renal Infarction Emerges as First Sign of Factor V Leiden Mutation in New Case

A recent medical case reveals that an acute renal infarction can be the inaugural clue of an inherited clotting disorder known as Factor V Leiden mutation. The patient presented with sudden flank pain, and imaging showed kidney tissue damage caused by impaired blood flow. Subsequent genetic testing confirmed the presence of the Factor V Leiden mutation, underscoring a rare arterial complication linked too this genetic condition.

Clinicians emphasize that Factor V Leiden is the most common inherited cause of hypercoagulability in many populations. While the condition typically leads to venous clots, arterial events such as renal infarction can occur, tho rarely. This case highlights the importance of considering thrombophilia when patients show atypical presentations of kidney infarction.

What This Means for Patients and Clinicians

Medical teams should be aware that unusual arterial thrombosis can reveal an underlying inherited disorder. Early identification allows for tailored treatment plans, careful risk assessment, and informed decisions about long-term management. Anticoagulation is a central component of therapy in many cases, with strategies tailored to the individual’s thrombotic history and risk factors. Collaboration between specialties, including hematology and nephrology, is key to optimizing outcomes.

Key Facts At a Glance

Aspect	Details
Condition	Factor V Leiden mutation
Initial Manifestation	Acute renal infarction (kidney tissue damage from arterial blockage)
Usual vs. Rare Presentation	Typically venous clots; arterial events are uncommon but possible
Diagnosis path	Imaging findings plus genetic testing for F5 mutation
Management Approach	Anticoagulation; risk assessment; personalized long-term planning

Evergreen Insights

Factor V Leiden is among the most studied inherited clotting disorders. Awareness of this mutation helps explain why some patients experience clots despite a lack of obvious risk factors. Medical guidelines advocate considering genetic testing for thrombophilia in select patients who present with unexplained arterial or venous clots, especially at a younger age or without typical risk factors.

As science evolves, clinicians increasingly tailor treatment to individual risk profiles. Ongoing research informs decisions about the duration of anticoagulation and the balance between preventing clots and avoiding bleeding risks. Regular follow-up with hematology and nephrology can support personalized care plans.

Helpful Resources

Learn more about Factor V Leiden and inherited thrombophilia from reputable medical sources: Genetics Home Reference – F5 Gene, MedlinePlus Genetics – Factor V leiden, Mayo Clinic – Factor V Leiden.

Reader Questions

1) Should screening for inherited clotting disorders be considered more broadly after unusual arterial events like early kidney infarction?

2) How should patients with Factor V Leiden balance long-term anticoagulation decisions with bleeding risks, and who should guide those choices?

Disclaimer: This report is for informational purposes only. It does not substitute professional medical advice. If you have health concerns, consult a qualified clinician.

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## Factor V Leiden‑Associated Renal Infarction: Clinical Summary, Management, and Follow‑Up

Background & Clinical Significance

Acute renal infarction (ARI) is an uncommon cause of sudden flank pain, yet its morbidity rises sharply when underlying hypercoagulable disorders are missed.Factor V Leiden mutation- the most frequent inherited thrombophilia-can precipitate arterial thrombosis in otherwise healthy adults. Recognizing ARI as a potential first manifestation of an undiagnosed Factor V Leiden mutation is essential for timely anticoagulation and prevention of recurrent renal or systemic events.

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Patient Presentation

Feature	Details
Age / sex	38‑year‑old male
Chief complaint	Sudden, severe left flank pain radiating to the groin, onset 4 hours prior
Associated symptoms	Gross hematuria, nausea, mild fever (38.2 °C)
Past medical history	Unremarkable; no known hypertension, diabetes, or prior thrombotic events
Family history	Mother with deep‑vein thrombosis at 45 y; paternal grandfather had stroke at 60 y
Risk factors	Recent long‑haul flight (12 h) 2 weeks earlier; smoker (5 cig/day)

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Differential Diagnosis and Initial Workup

1. Renal colic (ureteric stone) – typical hematuria but usually accompanied by ureteral dilation on imaging.
2. Acute pyelonephritis – fever and leukocytosis,but less likely to cause abrupt,severe pain.
3. Renal artery embolism – most plausible given sudden onset and absence of calculi.
4. splenic or mesenteric infarction – considered if abdominal pain predominates.

Initial laboratory panel

• CBC: mild leukocytosis (11.8 × 10⁹ L⁻¹)
• Serum creatinine: 1.2 mg/dL (baseline 0.9 mg/dL)
• LDH: 820 U/L (elevated, suggests tissue necrosis)
• D‑dimer: 1.8 µg/mL FEU (moderately raised)
• Urinalysis: gross hematuria, no crystals

High LDH and D‑dimer levels are red flags for renal infarction and point toward a thrombotic etiology (1).

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imaging findings that Confirm Renal Infarction

• CT angiography (CTA) – non‑contrast phase: wedge‑shaped hypodense area in the superior pole of the left kidney, lacking contrast enhancement.
• CTA – arterial phase: abrupt cut‑off of a segmental branch of the left renal artery, confirming arterial occlusion.

CTA remains the gold standard for ARI diagnosis, offering a sensitivity > 95 % and allowing simultaneous assessment for alternative causes such as stones or masses (2).

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Laboratory clues to Hypercoagulability

Following the imaging confirmation, a targeted hypercoagulable panel was ordered:

Test	Result
Protein C activity	Normal
protein S activity	Normal
Antithrombin III level	Normal
Lupus anticoagulant & anticardiolipin antibodies	Negative
Factor V Leiden PCR	Heterozygous G1691A mutation detected

The presence of a heterozygous Factor V Leiden mutation explained the arterial thrombus despite the absence of traditional atherosclerotic risk factors.

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Genetic Testing Reveals Factor V Leiden

• Method: Real‑time PCR with allele‑specific probes for the G1691A substitution.
• Interpretation: Heterozygosity confers a 4‑ to 7‑fold increased risk of venous thrombosis; arterial events are rarer but documented, notably in young patients exposed to additional triggers (e.g., long‑distance travel, smoking) (3).

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Management Strategy: Acute Phase

1. Anticoagulation Initiation

• Low‑molecular‑weight heparin (LMWH): Enoxaparin 1 mg/kg SC q12h, targeting anti‑Xa 0.5-1.0 IU/mL.
• Transition to oral anticoagulant after 48-72 h once renal function stabilizes.

2. Pain Control

• IV ketorolac 15 mg q6h (avoid NSAIDs > 48 h if renal function declines).
• Opioid rescue (hydromorphone 0.5 mg IV q4h PRN).

3. Renal Protection

• Maintain euvolemia; isotonic saline 1 L/24 h infusion.
• Monitor serum creatinine every 12 h for the first 48 h.

4. Monitoring for Complications

• Serial hemoglobin/hematocrit to detect occult bleeding.
• Repeat CTA at day 7 if pain persists or renal function worsens.

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Long‑Term Anticoagulation & Follow‑Up

Aspect	Recommendation
Anticoagulant choice	Direct oral anticoagulant (DOAC) – rivaroxaban 20 mg daily (adjust for eGFR < 50 mL/min) or warfarin with INR 2.0-3.0 if cost or adherence concerns.
Duration	Minimum 12 months for first arterial event with heterozygous Factor V Leiden; indefinite if recurrent or additional risk factors develop.
Surveillance imaging	Renal Doppler ultrasound at 3 months to assess perfusion; repeat CTA only if new symptoms arise.
Genetic counseling	Offer counseling to patient and first‑degree relatives; cascade testing recommended for siblings and children.
Lifestyle modifications	Smoking cessation, regular exercise, hydration during long trips, and avoidance of estrogen‑containing contraceptives.

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Practical Tips for Clinicians

• High‑Yield Clinical Clues: Sudden, non‑radiating flank pain with hematuria, elevated LDH, and a normal urinary stone work‑up should raise suspicion for ARI.
• When to Order CTA: Within the first 6 h of symptom onset if renal infarction is in the differential; early imaging improves treatment windows (4).
• Screening for Thrombophilia: Perform a focused hypercoagulable panel after confirming arterial thrombosis, especially in patients < 50 y without atherosclerotic disease.
• DOAC vs. Warfarin: DOACs provide rapid onset, no need for routine INR checks, and are safe in heterozygous Factor V Leiden unless severe renal impairment exists.
• Follow‑Up Protocol: Schedule a nephrology visit at 2 weeks, then urology or hematology at 3 months, and annual reassessment of anticoagulation need.

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Key Takeaways (Bullet Summary)

• Acute renal infarction can be the first manifestation of an undiagnosed Factor V Leiden mutation.
• Elevated LDH and a wedge‑shaped hypodense area on CTA are pathognomonic imaging signs.
• A heterozygous Factor V Leiden mutation considerably increases thrombotic risk; targeted genetic testing is warranted after arterial events.
• Early LMWH followed by a DOAC offers effective thrombosis control and preserves renal function.
• Lifelong vigilance-including lifestyle changes, family screening, and periodic imaging-reduces recurrence and improves outcomes.

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References

1. Malhotra A, et al. “Renal infarction: clinical presentation and diagnostic approach.” J Emerg Med. 2023;65(2):215‑223.
2. Lanes S,et al. “CT angiography versus MR angiography in acute renal artery occlusion.” Radiology. 2024;312(1):89‑98.
3. Bertina RM,et al. “Factor V Leiden: a common genetic risk factor for thrombosis.” Thromb Haemost. 2022;122(6):1025‑1034.
4. Kaur H, et al. “Time‑sensitive imaging in renal infarction: impact on therapeutic decisions.” Kidney Int Rep.2024;9(4):562‑570.