One Missing Protein, Two Failing Systems: Type 3 von Willebrand Disease

One Missing Protein, Two Failing Systems: Type 3 von Willebrand Disease

When von Willebrand factor is nearly absent, the platelet loses its anchor and factor VIII loses its protector, and even the vessel wall grows restless.

By William C. Aird, MD

Case Presentation

A man in the latter half of his thirties has carried a diagnosis of von Willebrand disease since infancy, when he bled excessively after circumcision. His whole life has been shaped by it. He bruises with almost no provocation. His gums bleed daily, especially after brushing and eating. He has frequent nosebleeds. By his own account he was hospitalized for bleeding more than twenty five times as a child.

Alongside that mucosal picture is a second, different one. He has suffered repeated bleeding into one ankle, which now has fixed loss of motion from the damage, and he has discomfort in other joints as well. That is not how mucosal bleeding disorders usually behave.

Mucosal bleeding (gums, nose, easy bruising) points to a problem of primary hemostasis, the platelet and von Willebrand factor. Bleeding into joints, with a target joint and arthropathy, points to a clotting factor problem, as in hemophilia. Which single diagnosis produces both patterns at once?

Explanation

Each of the wrong answers explains only half of him. Type 1 von Willebrand disease, a partial reduction in a normal protein, gives mucosal bleeding but rarely joint bleeding. Hemophilia A gives joint bleeding but not lifelong gum and nasal bleeding. Immune thrombocytopenia gives mucosal and skin bleeding alone. Only type 3, the near total absence of von Willebrand factor, produces both, and the reason is the subject of the next question.

Reveal: the laboratory picture

Von Willebrand factor is undetectable, yet factor VIII, a distinct protein made in a different place, is also markedly low. Why?

Explanation

This is the mechanistic center of type 3. Von Willebrand factor does two jobs. It bridges platelets to the injured vessel wall, and it carries factor VIII, shielding it from rapid clearance. Take von Willebrand factor away and both jobs fail. The platelet loses its bridge, which gives the mucosal bleeding, and factor VIII, unprotected, is cleared almost as fast as it is made, which drops it into a range low enough to bleed into joints. Factor VIII is still produced, so the level is low rather than zero, but it is low enough to matter. This also explains the screening tests. The reduced factor VIII prolongs the aPTT, while the PT, which does not depend on factor VIII, stays normal. One absent protein disables two arms of hemostasis and leaves its signature on two different pathways.

Reveal: the family

His mother is said to have von Willebrand disease. His young son was tested and does not have the disease. His siblings are unaffected.

Type 3 von Willebrand disease follows which inheritance pattern, and what does it mean for his son?

Explanation

Here type 3 parts company with the rest of von Willebrand disease. Types 1 and 2 are usually dominant, where a single variant allele is enough to show disease. Type 3 is recessive and requires two loss of function alleles, one from each parent. Because he carries two, every child of his inherits one and is therefore an obligate carrier, yet a child develops the disease only if the other parent supplies a second variant allele. His son can carry a variant and remain clinically unaffected, which fits. A carrier parent, in turn, may be silent or have only mild symptoms, which is worth remembering when a family history sounds softer than the proband’s disease.

Reveal: the marks of a lifetime of treatment

He was treated in the 1980s and early 1990s with cryoprecipitate, and later with a plasma concentrate containing both von Willebrand factor and factor VIII. Somewhere in those years, from the older products and from transfusions, he acquired hepatitis C.

That sequence is a small history of hemophilia care written on one body. Before viral inactivation and donor screening, the plasma products that stopped the bleeding also transmitted hepatitis C and HIV to a generation of patients with severe bleeding disorders. His chronic hepatitis C is a scar of that era. It is now curable, and he is receiving modern antiviral therapy, but the point stands: the treatment that saved him also injured him, and the injury outlasted the era that caused it.

Reveal: the anemia that will not resolve

For years he has been severely iron deficient, with ferritin in the single digits and hemoglobin falling at times below 6 g/dL, requiring intravenous iron again and again and, on occasion, transfusion and hospital admission for syncope. He bleeds from the gut. Yet upper endoscopy and colonoscopy, performed more than once, have not shown a source.

In a patient with type 3 von Willebrand disease and recurrent gastrointestinal bleeding that standard upper and lower endoscopy repeatedly fails to localize, which mechanism is most likely?

Explanation

This is where the case opens onto von Willebrand factor’s second life. Beyond hemostasis, von Willebrand factor helps to restrain the formation of new blood vessels. When it is absent, angiogenesis runs less checked, and fragile, malformed vessels, angiodysplasia, tend to develop, with a predilection for the small bowel that ordinary endoscopy does not reach. The result is exactly his picture: recurrent, obscure gastrointestinal blood loss with unrevealing standard scopes. The same mechanism, arriving from the opposite direction, produces the gut bleeding of acquired von Willebrand syndrome, where shear stress destroys the largest multimers. His poor adherence to prophylaxis worsens all of his mucosal bleeding, but bleeding that recurs and stays hidden from the scope should raise angiodysplasia specifically and prompt evaluation of the small bowel.

Reveal: replacement, and the cost of the gaps

Measured immediately after a prophylactic infusion, his von Willebrand factor antigen and activity rise to roughly 134 and 146 IU/dL and his factor VIII to about 56. By the next trough, his von Willebrand panel has fallen back to undetectable. His prophylaxis was escalated from twice to three times weekly precisely because the troughs were bottoming out and the iron deficiency kept returning.

Two things follow. First, replacement is pharmacology, not repair: infused von Willebrand factor clears quickly, so the peak looks like health and the trough looks like the untreated disease, and the schedule is really a negotiation with that decline. Second, the gaps have a price. Across these years, the times his levels were allowed to fall, whether by design or by missed doses, are legible as bleeds, drops in hemoglobin, and hospital visits. In a lifelong condition, adherence is not a footnote to the treatment. It is the treatment.

Teaching Points

• Type 3 is the double deficiency. Near absence of von Willebrand factor removes both the platelet’s adhesive bridge and factor VIII’s protector, so mucocutaneous bleeding and deep joint bleeding coexist. It is the one subtype of von Willebrand disease that behaves, in part, like hemophilia.
• Screening tests can finally turn abnormal here. In milder von Willebrand disease the PT and aPTT are typically normal. In type 3 the factor VIII falls far enough to prolong the aPTT. A normal aPTT never excludes von Willebrand disease, but a prolonged one in a lifelong bleeder should send you to a von Willebrand panel and not only to a hemophilia workup.
• Von Willebrand factor has a second life in the vessel wall. Its absence is linked to angiodysplasia and obscure gastrointestinal bleeding. Recurrent gut bleeding with unrevealing standard endoscopy in type 3 should raise that possibility and prompt small bowel evaluation, rather than repeated identical scopes.
• Type 3 is recessive, and that changes the counseling. It sits apart from the dominant inheritance of types 1 and 2. An affected parent alone does not doom the children, and a carrier parent may be entirely silent.
• Replacement corrects the peak, not the person. Levels rise sharply after infusion and fall to undetectable at trough as the protein clears, so prophylaxis frequency is set by the trough and by the cost of the gaps, which in this patient were counted in bleeds and in iron.

Why This Case Matters

Type 3 is usually introduced as the most severe form of von Willebrand disease, a difference of degree. It is more interesting than that. It teaches by subtraction carried to the extreme: remove von Willebrand factor almost entirely and you can finally see everything it had quietly been doing. The platelet loses its bridge, and the mucosa oozes. Factor VIII loses its protector, and the joints bleed like hemophilia. The vessel wall, no longer restrained, grows the fragile tangles that bleed in the dark for years. Read through its absence, one protein turns out to have been holding several jobs at once: adhesion, protection, and the quieting of the vessel. The iron deficiency and the hepatitis C are the marks left behind, by the absence itself and by the century of treatments that tried to answer it.