Patient-state medicine

1The patient must be part of the explanation#

A tumour can shrink while the person living with it grows weaker. A treatment can reach its target while the patient gains little useful function. A person can meet the criteria for recovery and still lack the capacity to withstand the next illness.

For that person, success means being able to think, move, work, care for someone else, and make plans again. Medicine needs to explain the distance between a biological change and that return to life.

Patient-state medicine organises diagnosis, prevention and treatment around a person’s changing capacity to respond, recover and retain function. It asks what is failing in this patient, which intervention their physiology can use, and what must be restored for benefit to last.

Cirsentra is a computational physiology lab building the scientific foundation for this approach. Our work connects original analyses of human biological data with experimental and clinical literature. From that work we have developed a connected account of how causes become disease, how treatments become responses, and how each response changes the patient’s future capacity.

Our ambition is to make differences between patients explainable, measurable and actionable. A diagnosis should lead to a treatment decision that accounts for the person who must live with its consequences.

2Give patient differences a physiological explanation#

Two people can share a diagnosis and need different interventions. The same inherited risk can lead to different disease trajectories. A treatment that helped last year can fail this year. An apparently modest illness can cause lasting decline in one person while another recovers.

Calling these differences patient variability names the problem. Explaining them requires following what happens between a cause and its effect.

A signal or drug must reach the right place. The receptor must be able to use it and pass it on. The tissue must have the energy and materials to carry out the response. Other organs must support that work. The response must end, its products must be cleared, and the capacity it consumed must be rebuilt.

Failure at each step creates a different problem and a different opportunity to intervene.

The patient’s state determines which paths from cause to consequence are available at that moment. A useful account of state therefore includes receiving capacity, energy, organ coordination, compensation and recovery. It also includes the history that made those capacities what they are.

This is the meaning of reserve geometry: the arrangement of capacities and constraints that determines what a body can do, what that effort costs, and what remains possible afterwards. One organ may maintain its output because another is doing extra work. A reassuring measurement can coexist with a growing cost elsewhere.

Patient-state medicine makes that cost, and the capacity behind the measurement, part of the explanation.

3Every response helps set the next one#

Cirsentra’s Reserve-Setting Law states:

Each biological response and its recovery set the capacity available for the next response.

The body that encounters the next infection, treatment or physical demand has been changed by what came before. It may have rebuilt what it used, gained capacity through adaptation, or carried a deficit forward.

The reserve-setting cycle follows that change: what arrives, how it is received, what work it triggers, which systems compensate, how the response ends, and what is reconstructed afterwards.

This gives recurrence and loss of treatment response a physiological question: what was available the first time that is no longer available now? It also gives prevention a task: identify the capacity being lost while the patient can still produce an apparently normal result.

Recovery becomes part of how the next outcome is produced. Treatment schedules, rehabilitation and repeat dosing have to account for what the previous response left behind.

Our work on the first reserve takes this sequence back to development before birth. The body constructs the vessels, receiving cells and systems for growth, defence and repair that later demands will encounter. Inherited biology and developmental conditions contribute to that starting architecture, and life continues to reshape it. Patients begin adult life at different baselines.

A patient’s future depends partly on what their body has already had to do, and how well it was able to rebuild.

4A treatment needs a receiver that works#

Much of medicine acts by sending an instruction: a hormone, a drug, a nutrient, a stimulus. Its effect depends on the receptor that receives it and the signalling that carries it onward.

Cirsentra’s competent receiver makes that requirement explicit. A receptor must be accessible, intact, correctly placed and connected to the processes that carry its signal onward. Its continued availability and renewal decide whether the same response can be produced again.

Counting receptors or measuring their gene expression answers part of this question. The physiological or pharmacological effect of an input depends on the currently usable receiver population and its renewal dynamics, not on gene expression or total receptor abundance alone. A target can be detectable while too little usable capacity remains to produce the required response.

This changes the intervention question. More signal helps when supply is low. When the receiver is impaired, treatment has to address that impairment or use another functioning route.

Reception and execution also have different requirements. In energy resistance, the instruction is received while the tissue lacks the energy to carry it out. Other systems compensate, consuming further resources to maintain output. Finding where that cost accumulates explains why function deteriorates before routine measurements change.

The clinical task is to tell these states apart. A shortage of signal, a damaged receiver and an energy-limited response call for different solutions.

5The body has an architecture for setting state#

The brain responds continually to the condition of the body, coordinating circulation, fluid balance, endocrine activity, immune responses, daily rhythms and behaviour. That coordination depends on specialised interfaces through which information passes between blood, brain and cerebrospinal fluid.

The anatomy is specific. The blood-brain barrier is intact across more than 99 per cent of the brain. A small set of structures are the constitutive exceptions: the area postrema, the median eminence, the subfornical organ and the vascular organ of the lamina terminalis, the choroid plexus, the pineal, and the neurohypophysis. Their vessels are fenestrated by design, so circulating signals meet neural tissue directly. Local cellular barriers regulate onward access and help define what each interface receives and transmits.¹

Eight systemic signals reach the brain through these interfaces and through no other route: leptin, insulin, insulin-like growth factor, thyroid hormone, interleukin-1, tumour necrosis factor, interleukin-17 and cortisol. One pair of cells integrates all eight, which places it between body and brain as a causal bottleneck. In the median-eminence endothelium the sensor and the actuator sit on the same cell, the interleukin-1 receptor with its accessory protein alongside endothelin-1 and nitric oxide synthase 3, so the transfer happens inside a single cell type, where it can be read directly.

Medicine already treats at these sites without naming them as a system. Antiemetics act at the area postrema. Fezolinetant acts at the arcuate nucleus for menopausal vasomotor symptoms. The appetite and nausea effects of the GLP-1 drugs arise at the same two sites. Their status as one coordinated reading surface is new.

Cirsentra brings these sites and related interfaces together as the circumventricular sentinel network: a distributed blood- and cerebrospinal-fluid-facing control system that reads systemic state and converts it into endocrine, autonomic, barrier, pressure-volume, phase and behavioural outputs. A change at one interface influences several downstream systems because of the connections it controls.

This is central to our account of patient state. It gives specific places to investigate how a problem elsewhere in the body changes brain function, and how a change in brain-body communication reshapes the condition of the whole patient.

6What reaches the system changes what it can do#

A receiving cell meets a changing environment: hormones, nutrients, medicines, inflammatory signals and microbial products. Cirsentra calls these external effectors because they act on the receiving system from outside it. Their sources lie inside the body and outside it.

They travel mainly in plasma, and some of them cut and degrade the receptors that treatment depends on. Our work on the systemic effects of the oral microbiome forms part of this wider question. The scientific task extends from identifying what is present to understanding what it does, where its effects occur, and how those effects alter the patient’s capacity to respond.

Across organs, shared signals must produce different but compatible actions. The liver, muscle, kidney and brain have different jobs. Cirsentra’s systemic metabolic readability describes how circulating command and material fields acquire organ-specific meaning through arrival, receiver capacity, execution, compensation and recovery.

Health depends on those different responses working together. A hormone level alone cannot describe that coordination. It also takes knowing which tissues can use the signal, which must compensate, and how the work affects subsequent recovery.

Our findings on sex- and life-stage receiver architecture add another dimension: the receptors and signalling available for these responses differ between people and change across a life. Those differences belong in the explanation of disease and treatment response, and in the design of the measurements used to assess them.

Together, these discoveries connect what reaches the patient, what the patient can do with it, and how the response changes what comes next.

7Why this layer has been difficult to see#

Modern biology resolves molecules, maps individual cells and reveals changes in gene activity at extraordinary scale. Clinical medicine measures organ function, disease severity and physiological reserve. Each provides a view of the patient, and connecting those views across organs and through time is a further scientific task.

Specialisation divides that task. A receptor is studied in one field, its circulating influences in another, the patient’s symptoms in a third, and recovery in a fourth. A measurement of abundance is available where a measurement of usable capacity is needed. A resting result is recorded where the decisive information is how the system responds and rebuilds.

Anatomy creates a further difficulty, and it is the deeper reason. A structure can occupy a unique causal position without expressing unique molecules. Topology can be the source of biological function. Any method that searches for molecular distinctiveness passes over a structure whose importance lies in where it sits, what reaches it, and where its output goes. The interfaces above are exactly of that kind, which is why they were catalogued one at a time as anatomical curiosities and never assembled into a system.

The same gap runs through computational biology. The State model from Arc Institute, the largest perturbation model built so far, was trained on nearly 170 million observed cells and more than 100 million perturbed cells across 70 cell lines.² Every perturbation in that training was delivered outside a body. A cell in culture carries no endocrine axis, no immune context, no circulating protease load, and no interface that sets its state from the blood. A model trained this way predicts what a cell does when perturbed. It cannot say which patient is in a state where that perturbation helps. The layer is missing from the data, and it is missing because nobody had mapped it.

Cirsentra uses an AI-assisted knowledge graph to bring human data, mechanisms, disease trajectories, drug effects and source evidence into a queryable body of knowledge. AI retrieves and connects material at scale. Human scientific judgment directs the questions, weighs explanations and chooses the next analyses and experiments. This makes it possible to carry knowledge across disease boundaries while keeping the mechanism and the evidence in view.

9What should change for patients and clinicians#

A patient should be able to ask:

• What is preventing me from improving?
• What does this treatment require my body to be able to do?
• What needs to recover before the next treatment or demand?
• How will we know that I am regaining capacity for everyday life?

Patient-state medicine turns these questions into a diagnostic and treatment agenda. It calls for assays that distinguish failed delivery, impaired reception, limited execution and incomplete recovery; for treatment choices linked to those findings; and for follow-up that tracks whether useful capacity returns.

For clinicians, the aim is a physiological reason for a decision: why this intervention, for this patient, at this time. Dose and timing become questions about drug exposure and about the tissue’s ability to respond. A poor response prompts investigation of the failed step and of the conditions needed for a better one.

It also changes what trials and care pathways count as success. In oncology, tumour control and the patient’s ability to tolerate treatment and recover belong in the same account. In muscle loss, preserving tissue has to translate into useful strength and function. In brain disease and rehabilitation, the capacity to sustain recovery belongs alongside the immediate response.

The standard we seek is improvement that leaves the patient more able to live, and more able to meet what comes next.

10What should change for drug development#

Target-capacity pharmacology preserves, rebuilds, bypasses, or diversifies usable target capacity separately from changing ligand supply, occupancy, delivery, or downstream pathway tone.

Its central sequence is:

1. Drug exposure
2. target engagement
3. usable target capacity
4. physiological response
5. clinical benefit.

Each transition has requirements. Measuring whether a drug reaches and binds a target leads to the next question: does enough usable target capacity remain, in the right tissue and state, to produce the intended benefit?

That question changes what we develop. Alongside altering a signal or blocking a pathway, we can seek interventions that protect or restore the capacity a treatment needs. It changes how we select patients: a trial can measure the state the drug’s mechanism requires, then test whether that state predicts benefit. It changes how we investigate failure: insufficient exposure, impaired target function and a downstream execution limit become distinct explanations to examine.

The patient’s state also changes during treatment. Drug development therefore has to ask whether the response can be repeated, what recovery it requires, and whether improving one system imposes an unsustainable cost on another.

The opportunity is to make physiological fit a design criterion from target selection through clinical development. The same science guides new drug targets, companion assays, treatment combinations and intervention timing.