The scale of the problem justifies the effort. The most recent estimates cited by the authors suggest that roughly six percent of United States adults and half a percent of children and adolescents are still living with new or persistently worsened symptoms that began shortly after an acute SARS-CoV-2 infection. For clinical purposes, the authors define Long COVID as new or worsened symptoms developing after confirmed or suspected infection and persisting for more than three months, a deliberately broad formulation that sidesteps the stricter laboratory-confirmation requirements of research definitions. The dominant symptoms cluster around fatigue, post-exertional malaise, cognitive impairment often called brain fog, and orthostatic intolerance, the lightheadedness and palpitations that appear or worsen when a patient stands upright.

What makes the review distinctive is its use of clinical vignettes that mirror how patients actually describe their lives. In one case, a 32-year-old woman with a history of anxiety reports four months of fatigue that is qualitatively different from anything she has felt before. After minimal activity, she describes crashing, as though wearing a lead coat, with profound exhaustion and difficulty thinking that can persist for hours to days. Even preparing meals or answering emails has become a hurdle, and she has cut back her work hours. Her symptoms began about a month after a mild COVID-19 infection, a temporal link that might easily be missed if a clinician never asks about preceding illness.

A second vignette captures the dysautonomia pattern: a previously athletic 19-year-old develops palpitations, lightheadedness, and near-fainting on standing, symptoms that improve when she lies down. She recalls an upper respiratory illness two weeks before onset, and although she never tested herself, multiple family members had confirmed COVID-19 at the time. A third describes a 45-year-old aerospace engineer whose forgetfulness, word-finding difficulty, and slowed processing speed have cost him deadlines at work, all despite a normal basic laboratory evaluation. Together, the cases illustrate the review’s central message: Long COVID frequently announces itself through recognizable symptom clusters, and related conditions such as myalgic encephalomyelitis/chronic fatigue syndrome and postural orthostatic tachycardia syndrome often ride alongside it.

Beneath the clinical patterns, the authors propose a three-part conceptual framework for what SARS-CoV-2 actually leaves behind. The first category is a hit-and-run phenomenon, in which acute infection causes direct end-organ tissue injury with lasting consequences, such as pulmonary fibrosis or vascular events. The second is a stressor effect, in which the infection reduces physiological reserve and unmasks or accelerates chronic diseases like diabetes, hypertension, or rheumatoid arthritis in the following weeks and months. The third and most scientifically contested category is ongoing biological dysregulation, encompassing persistent viral reservoirs, immune dysregulation, gut dysbiosis, mitochondrial dysfunction, and microvascular clotting, processes repeatedly identified in basic science studies but largely invisible to current clinical diagnostic tools. Management of the first two categories follows standard practice, the authors note, while the third currently rests on rehabilitation and supportive care.

Diagnostically, the review resists exotic testing. Because no clinically available biomarker can confirm or exclude Long COVID, and severe symptoms can coexist with entirely normal conventional results, the workup serves mainly to rule out competing diagnoses and addressable sequelae. The authors recommend a focused physical examination guided by the patient’s symptoms, with particular attention to orthostatic vital signs, which are often skipped and frequently abnormal in this population. Targeted laboratory and imaging studies, including complete blood count, metabolic panel, thyroid function, and inflammatory markers, follow the same logic a primary care clinician would apply to any undifferentiated complaint. A validated ten-item questionnaire for post-exertional malaise, the DSQ-PEM, can help document a symptom that patients often struggle to articulate.

On treatment, the message is sobering but constructive: there is no cure, and no FDA-approved medication, yet validation and education alone can meaningfully improve quality of life. The authors emphasize that mental health conditions are not the cause of Long COVID, but the illness frequently produces new or worsened depression and anxiety, partly because patients do not feel believed by clinicians or loved ones. Nonpharmacologic strategies form the backbone of care. Activity pacing, energy conservation, and task modification, such as spreading grocery shopping and meal preparation across separate days or using a scooter and a seated chopping station, help patients live within their energy envelope. Referral to therapists experienced with chronic fatiguing illnesses, typically in neurorehabilitation rather than orthopedic settings, can be transformative: physical therapy for fatigue and activity intolerance, occupational therapy for self-care and job demands, and speech therapy for attention, memory, and breathing discomfort despite normal pulmonary tests.

One warning stands out with unusual force. While some patients tolerate gradual, supervised exercise progression, graded exertion must be approached with extreme caution in patients with post-exertional malaise. The authors cite evidence that even seemingly minor overexertion can trigger delayed symptom flares and has been associated with amyloid deposition, reduced mitochondrial enzyme activity, and signs of severe skeletal muscle damage in affected patients. For those with orthostatic intolerance, simpler measures carry real benefit: increasing daily fluid intake to 2.5 to 3.5 liters and sodium to 2.8 to 4 grams, equivalent to 7 to 10 grams of salt, alongside compression garments such as waist-high stockings or an abdominal binder, provided no contraindications exist.

Pharmacologic management remains symptom-based, borrowing indications from other contexts: beta blockers or ivabradine for POTS, stimulants for attention-dominant brain fog, gabapentinoids for neuropathic pain, and SSRIs for new or worsened mood symptoms. Two off-label options receive special mention. Low-dose naltrexone, an opioid receptor blocker, has been associated in some patients with improved pain, fatigue, and cognition, and a 2026 systematic review and meta-analysis examined the evidence base. Patients with suspected mast cell activation syndrome triggered by Long COVID sometimes report relief from combined H1 and H2 antihistamines. The authors also address the longer arc of illness: symptoms persist beyond one year in roughly a quarter of patients and beyond two years in about ten percent, making documentation of functional impact, workplace accommodation letters, and disability paperwork an essential, billable-worthy part of primary care.

Perhaps the most practical contribution is a set of principles for delivering all of this within a standard visit. The authors advise screening for preceding illness and symptom duration in the history, asking which symptom is most bothersome right now, and tackling only one or two symptoms per visit while leveraging longitudinal follow-up. Medication trials should be stepwise, one intervention at a time, starting low and titrating slowly, with de-prescribing of drugs that may worsen fatigue or cognition. Written after-visit summaries matter disproportionately for patients with cognitive symptoms, and telehealth or first-appointment scheduling can spare fatigued patients the exertion of a waiting room. On prevention, the review is equally concrete: vaccination shows a dose-dependent reduction in Long COVID risk, early outpatient antivirals offer modest protection, with nirmatrelvir/ritonavir associated with a 26 percent relative risk reduction, molnupiravir 14 percent, and ensitrelvir 45 percent, while metformin was linked to a 41 percent reduction in incidence in a randomized trial. Indoor air filtration, N95 or KN95 masking, and isolation during infectivity round out the defensive toolkit. Until reliable biomarkers and curative therapies arrive, the authors argue, the frontline of Long COVID medicine will remain the primary care office, and clinicians equipped with a structured approach can already change what the illness means for the patients living with it.

Subject of Research: Clinical evaluation and management of Long COVID in primary care

Article Title: Long COVID in Primary Care: A Practical Approach to Evaluation and Management

Article References: Chopra, A., Bonilla, H. F., & Cheng, A. L. (2026). Long COVID in Primary Care: A Practical Approach to Evaluation and Management. Journal of General Internal Medicine. https://doi.org/10.1007/s11606-026-10901-w

Image Credits: AI Generated

DOI: 10.1007/s11606-026-10901-w

Keywords: Long COVID, primary care, SARS-CoV-2, post-exertional malaise, dysautonomia, POTS, brain fog, ME/CFS, diagnosis, rehabilitation, antivirals, prevention

The commentary, authored by Lotte Habermann-Horstmeier of the Villingen Institute of Public Health in Germany, does not present new experimental data. Instead, it offers something arguably more valuable at this stage of the field: a structured, testable framework. Drawing on a targeted synthesis of literature from PubMed and Web of Science, the author sorts evidence into three categories—direct SLE findings, findings from ME/CFS research, and cross-condition mechanistic inference—and insists that these be kept rigorously separate. The result is a hypothesis-generating proposal for an SLE–ME/CFS research phenotype, a defined subgroup of lupus patients whose symptoms persist for at least six months, worsen after exertion, and include unrefreshing sleep, cognitive symptoms, or orthostatic intolerance, once alternative explanations and comorbidities have been systematically excluded.

The clinical rationale for such a phenotype rests on a well-documented gap between conventional disease measures and patient experience. In lupus, indices of inflammatory activity often normalize under treatment, yet patient-reported outcomes tell a different story. Fatigue ranks among the most prevalent and disabling complaints across the disease course, and studies of patients in remission have repeatedly documented impaired physical function, reduced exercise capacity, sleep disturbance, and neurocognitive symptoms that conventional lupus metrics fail to capture. This discordance has practical consequences: patients whose laboratory values look reassuring may nonetheless be functionally limited, and clinicians lack a framework for understanding—or investigating—why.

What makes the proposed phenotype more than a descriptive label is the mechanistic scaffolding beneath it. The commentary assembles direct evidence from lupus research pointing to several interacting biological systems. Residual immune activation persists in many patients despite apparent disease control, with ongoing immune cell activation and inflammatory signaling detectable below the threshold captured by clinical indices. Oxidative stress, an imbalance between reactive oxygen species and antioxidant defenses, has been documented in SLE and can damage cellular components ranging from lipids to DNA. Mitochondrial alterations—the dysfunction of the organelles that generate cellular energy—have likewise been reported, offering a plausible route from biochemical injury to the fatigue and exercise intolerance patients describe.

Vascular and autonomic mechanisms form a second pillar of the framework. Endothelial dysfunction, a impairment of the blood vessels’ inner lining that precedes atherosclerosis, is well established in lupus and contributes to the disease’s elevated cardiovascular risk, but it may also compromise tissue perfusion during exertion and in the brain. Dysautonomia—disordered regulation by the autonomic nervous system—has been described in SLE patients and can produce orthostatic intolerance, the lightheadedness, palpitations, and cognitive dulling that occur when standing disrupts cerebral blood flow. These findings matter because they map directly onto symptoms that dominate the lived experience of the proposed subgroup: exercise that triggers a disproportionate crash, sleep that does not restore, and thinking that falters when upright.

It is here that the commentary’s most provocative move occurs: importing carefully flagged mechanistic insights from ME/CFS research. That field, long marginalized but increasingly rigorous, has accumulated human evidence of impaired cellular energetics, with studies suggesting that energy metabolism in patient cells behaves abnormally under stress; of autonomic dysfunction measurable in the clinic; of altered cerebral perfusion on neuroimaging; and of neuroimmune dysregulation involving inflammatory signaling that reaches the central nervous system. Post-exertional symptom exacerbation—the hallmark worsening of symptoms hours to days after physical or cognitive effort—serves as the condition’s defining feature and a key anchor for the proposed lupus phenotype. The author is explicit that these ME/CFS findings are hypotheses for lupus, not established facts: they converge plausibly with direct SLE evidence, but they require direct validation in lupus cohorts before any conclusion can be drawn.

The framework’s deliberate non-linearity is one of its distinguishing technical features. Rather than proposing a single causal chain—molecule X causes symptom Y—the author describes interacting immune, metabolic, vascular, autonomic, and neurocognitive mechanisms that may reinforce one another dynamically over time. Mitochondrial dysfunction, for instance, could amplify oxidative stress, which in turn could worsen endothelial function and autonomic regulation, while neuroimmune signaling could sensitize the brain’s fatigue and cognitive circuits. Such feedback structures resist the one-biomarker-one-diagnosis model and instead call for multidimensional phenotyping: simultaneous measurement of immune markers, redox balance, vascular function, autonomic testing, exercise physiology, and neurocognitive performance in the same patients, tracked longitudinally.

Methodological caution runs throughout the proposal. The commentary is explicitly a theoretical, non-systematic synthesis, prioritizing human studies, systematic reviews, meta-analyses, and translational work, and it stops short of defining a new diagnostic entity or a fixed disease trajectory. The proposed phenotype is framed as a research construct—a way to stratify patients for prospective longitudinal studies—rather than a clinical diagnosis. This distinction is important for lupus care, where symptoms such as fatigue and cognitive difficulty can also arise from hypothyroidism, anemia, sleep apnea, depression, medication side effects, or active disease that standard measures miss. The framework therefore requires structured exclusion or assessment of alternative explanations before a patient is classified within the subgroup, mirroring the case-definition discipline developed in ME/CFS research.

If the hypothesis survives prospective testing, the implications could be substantial. A validated SLE–ME/CFS research phenotype would give investigators a stratification tool for clinical trials, separating patients whose persistent symptoms arise from ongoing inflammatory activity from those whose illness follows a different biological path. It could sharpen biomarker discovery by directing attention toward autonomic, endothelial, mitochondrial, and neuroimmune measures rather than conventional serology alone. And it could reshape supportive care, since interventions developed for ME/CFS—pacing strategies to avoid post-exertional crashes, graded approaches to rehabilitation, orthostatic management—might be adapted and formally tested in the lupus subgroup, rather than applied indiscriminately to all patients.

The proposal also carries a message about how medicine handles diseases that fall between specialties. Lupus is the rheumatologist’s territory; ME/CFS remains contested and under-resourced; and patients whose illness straddles the two risk falling into the gap. By articulating a phenotype that borrows mechanistic rigor from one condition to explain unresolved symptoms in the other, the commentary offers a template for hypothesis-driven bridge-building across diagnostic boundaries. The author is careful to frame the work as hypothesis-generating, and the next step—longitudinal, multidimensional studies of lupus patients with persistent symptoms—will determine whether the SLE–ME/CFS research phenotype describes a real biological subgroup or merely a useful way of organizing uncertainty. Either outcome would advance a conversation that many patients, whose suffering persists long after their inflammation has quieted, have been waiting for the field to have.

Subject of Research: Persistent fatigue and related symptoms in long-standing systemic lupus erythematosus and their proposed mechanistic overlap with ME/CFS

Article Title: Persistent symptom burden in long-standing systemic lupus erythematosus: a subgroup-focused hypothesis for an SLE–ME/CFS research phenotype

Article References: Habermann-Horstmeier, L. (2026). Persistent symptom burden in long-standing systemic lupus erythematosus: a subgroup-focused hypothesis for an SLE–ME/CFS research phenotype. Journal of Translational Medicine. https://doi.org/10.1186/s12967-026-08867-8

Image Credits: AI Generated

DOI: 10.1186/s12967-026-08867-8

Keywords: systemic lupus erythematosus, ME/CFS, chronic fatigue, post-exertional malaise, dysautonomia, endothelial dysfunction, mitochondrial dysfunction, oxidative stress, neuroimmune dysregulation, orthostatic intolerance, disease phenotype, Journal of Translational Medicine