There’s a pattern most Lyme clinicians eventually notice — but rarely see discussed in the literature.

A patient walks in with a classic story:

• fatigue
• migrating symptoms
• cognitive changes
• maybe even a known tick exposure

You run testing.

It comes back negative.

And something doesn’t sit right.

Now here’s where the pattern gets interesting.

Over time, you start to notice:

This seems to happen more often in women.

The Problem We Don’t Talk About

Lyme testing is already imperfect. We all know that.

Early sensitivity is limited. Timing matters. Immune response matters.

But what if there’s another layer most clinicians aren’t accounting for?

What if the test itself performs differently depending on the patient sitting in front of you?

A recent 2026 study out of Johns Hopkins adds a compelling piece to this puzzle.

And once you see it, you can’t unsee it.

A Subtle — But Critical — Finding

In this prospective cohort of 243 patients with confirmed early Lyme disease:

• Men were significantly more likely to test positive on two-tier serology
• Pre-menopausal women were the least likely to be seropositive
• This difference largely disappeared after menopause

Let’s pause there.

Because this isn’t just a statistical curiosity.

This is a clinical signal.

What This Actually Means

If two patients walk into your clinic:

• same infection
• same timeline
• same exposure

…but one is male and one is a pre-menopausal female…

The male patient is significantly more likely to test positive.

Not because he’s more infected.

But because his immune system is responding differently.

Lyme Testing Isn’t Just About the Pathogen

This is where many clinicians get tripped up.

We tend to think of Lyme testing as:

“Do they have Borrelia or not?”

But serologic testing isn’t detecting the organism.

It’s detecting the host response to the organism.

And that response is influenced by:

• hormones
• immune regulation
• inflammatory signaling
• timing of infection

Which means:

Testing is not just pathogen-dependent. It’s host-dependent.

The Estrogen Connection (And Why It Matters)

The study authors suggest that hormonal differences — particularly estrogen — may play a role in shaping early immune response.

We already know from broader immunology:

• Estrogen modulates cytokine signaling
• It influences antibody production
• It can dampen or shift inflammatory responses

So it’s entirely plausible that:

Pre-menopausal women may mount a less “detectable” antibody response early on.

And if that’s true…

Then we’re not just dealing with imperfect testing.

We’re dealing with systematically biased testing.

The Clinical Mistake I See Most Often

Here’s how this shows up in real life.

A patient — often a woman — presents with:

• multi-system symptoms
• evolving neurologic or inflammatory patterns
• a timeline consistent with tick exposure

Testing comes back negative.

And the conclusion becomes:

“This probably isn’t Lyme.”

That’s the mistake.

Not because testing is useless.

But because testing is being over-weighted relative to clinical pattern recognition.

A Case Pattern You’ve Probably Seen

If you’ve treated enough of these patients, this will sound familiar.

A woman presents with:

• fatigue that doesn’t track with lifestyle
• cognitive slowing
• intermittent autonomic symptoms
• migrating pain

Initial Lyme testing: negative.

Months pass.

Symptoms progress.

Eventually, one of three things happens:

1. Repeat testing turns positive
2. Co-infections emerge more clearly
3. Empiric treatment leads to clinical response

And in retrospect, the pattern was there all along.

The test just didn’t reflect it — yet.

Why This Matters More Than Ever

Because this isn’t just about missing early Lyme.

This is about what happens next.

Delayed diagnosis increases the risk of:

• immune dysregulation
• persistent symptoms
• more complex multi-system illness

And interestingly, women are also more likely to develop persistent post-treatment symptoms.

Which raises an important question:

Are we missing the window for optimal intervention more often in women?

The Bigger Clinical Insight

This study reinforces something that experienced clinicians already know intuitively:

The host response is the disease.

Not just the infection.

Not just the organism.

But the interaction between the organism and the immune system.

And that interaction is not the same across patients.

Practical Takeaways for Clinicians

If you’re treating Lyme — or even considering it — here’s what to take from this:

1. Don’t anchor on negative testing

Especially in:

• early infection
• pre-menopausal women
• evolving symptom patterns

2. Weigh pattern recognition more heavily

Ask:

• Does the timeline fit?
• Does the symptom constellation evolve in a Lyme-like way?
• Are there co-infection signals?

3. Understand testing limitations at a deeper level

It’s not just:

• “early vs late disease”

It’s:

• host-dependent variability in immune response

4. Consider repeat or alternative testing strategies

If suspicion remains high:

• repeat testing
• look at co-infections
• evaluate immune markers

5. Trust clinical reasoning

This is where experience matters.

And it’s exactly the skillset most clinicians were never formally taught.

This Is Where Lyme Chess Begins

Cases like this are why Lyme treatment is rarely linear.

It’s not:

test → diagnose → treat

It’s:

observe → interpret → adjust → reassess

This is what I often refer to as Lyme Chess.

You’re not just reacting to data.

You’re interpreting patterns over time.

Final Thought

The takeaway here isn’t that Lyme testing is broken.

It’s that:

It’s incomplete.

And in some patients — especially women — it may be systematically less informative early on.

The clinicians who get the best outcomes aren’t the ones who ignore testing.

They’re the ones who understand what the test can and can’t tell them.

If This Resonates

This kind of pattern recognition is exactly what we focus on inside the LDPC Lyme Disease Mentorship program — helping clinicians move beyond protocols and into true clinical strategy.

If you’ve seen cases like this, I’d be curious:

Have you noticed this pattern in your own patients?

Reference:
Rebman AW, Yang T, Aucott JN. Sex and menopause-based differences in presentation of early Lyme disease: A prospective cohort study. Clin Exp Med. 2026;26(1):139. Published 2026 Feb 7. doi:10.1007/s10238-026-02063-0