JERUSALEM (VINnews) — The following article is based on a Ynet presentation by Prof. Yuval Tal, director of the Immunology and Allergy Unit at Hadassah Ein Kerem Medical Center.

For decades, doctors treated immune-related diseases based largely on the affected organ or the diagnosis itself. Today, advances in immunology are reshaping that approach, with researchers increasingly focusing on the underlying biological pathways driving disease rather than the condition’s name.

The shift is fueled by a growing number of precision biologic drugs that target specific immune mechanisms. Although many of these medications were originally developed for individual diseases, physicians are discovering that the same immune pathway can be responsible for a variety of seemingly unrelated conditions. As a result, treatments designed for one illness may prove effective for another.

Instead of asking only what disease does this patient have, doctors are increasingly asking which immune mechanism is causing it?

One striking example involved a cancer patient whose disease was under control but who suffered from relentless, debilitating itching that conventional treatments failed to relieve. Antihistamines, steroids and other therapies had no effect. The constant suffering left him unable to sleep or function normally, and he eventually purchased a ticket to Switzerland to pursue assisted death, not because of his cancer, but because of the unbearable itching.

Rather than viewing the treatment failures as the end of available options, physicians treated them as an important clue. If antihistamines were ineffective, histamine was probably not responsible for the symptoms. Doctors instead investigated whether a different immune pathway was driving the condition.

They focused on cytokines involved in so-called type 2 inflammation, immune signaling proteins already known to play a central role in diseases such as asthma and atopic dermatitis. Although the biologic drug targeting this pathway had not been developed for cancer-related itching, doctors decided to try it.

After only three injections, the patient’s symptoms disappeared. At a follow-up appointment, he tore up his ticket to Switzerland.

The success was not an isolated event. Similar cases prompted researchers to formally study whether patients suffering severe itching related to cancer or cancer treatments might benefit from the same therapy. While researchers acknowledge that not every patient responds similarly and the mechanisms are still being investigated, the cases highlight the value of identifying the biological pathway responsible for disease rather than relying solely on traditional diagnoses.

Immunology was once viewed as a relatively specialized field focused primarily on infections and allergies. That perception has changed dramatically.

Scientists now recognize that the immune system influences nearly every organ and plays a role in a wide range of medical specialties, including oncology, hematology, rheumatology, dermatology, pulmonology, gastroenterology, neurology, infectious diseases and gynecology.

The COVID-19 pandemic brought public attention to the importance of the immune system, but experts note that the scientific revolution began years earlier as researchers uncovered increasingly complex interactions between immune cells and disease.

The immune system does far more than fight bacteria and viruses. It helps repair injured tissue, regulates inflammation, identifies and destroys cancer cells and maintains the body’s internal balance. When these mechanisms malfunction, the consequences can include allergies, autoimmune disorders, immune deficiencies, chronic inflammatory diseases and even some cancers.

Many people associate immunology exclusively with allergies, but specialists emphasize that allergy represents only one aspect of the broader field.

An allergy is an abnormal immune response to normally harmless substances such as foods, medications, pollen or insect venom. Immunologists also diagnose and treat congenital and acquired immune deficiencies, autoimmune diseases, eosinophilic disorders and complex inflammatory conditions involving multiple organ systems.

This broader perspective has become increasingly important because different symptoms affecting the skin, lungs or digestive tract may all stem from the same underlying immune pathway.

New biologic medications allow physicians to target specific cells, proteins or immune pathways rather than suppressing the entire immune system, reducing unnecessary side effects while improving effectiveness.

This precision approach has transformed care for many conditions once managed only by controlling symptoms. Researchers continue to identify shared immune mechanisms across diseases, creating opportunities to apply existing therapies in entirely new settings.

The revolution in immunology is not limited to developing new treatments. It also involves reexamining long-standing diagnoses that may no longer be accurate.

Food allergies provide one example. Although food allergy diagnoses have increased sharply among children, not every suspected allergy proves genuine, and many childhood diagnoses remain in medical records for years without reassessment.

When appropriate, allergists perform supervised food challenges in which patients gradually consume the suspected food under medical supervision. Many children ultimately discover they are not allergic, freeing families from unnecessary dietary restrictions and constant anxiety.

Penicillin allergy presents another common problem. Hundreds of thousands of Israelis carry a penicillin-allergy label despite never having had a true allergy or having outgrown one years earlier.

Sometimes a child develops a rash during a viral illness while taking antibiotics, and the rash is mistakenly attributed to penicillin. Without reassessment, that diagnosis can remain for life, limiting access to one of medicine’s most useful antibiotics and forcing physicians to prescribe alternatives that may be less effective or more expensive.

Doctors also stress the importance of distinguishing true allergies from unrelated conditions. Lactose intolerance, for example, results from the body’s inability to digest lactose because of insufficient lactase enzyme—not from an immune response.

Similarly, glucose-6-phosphate dehydrogenase (G6PD) deficiency, sometimes mistakenly called a “fava bean allergy,” is an inherited enzyme deficiency rather than an allergy. People with the condition can develop destruction of red blood cells after eating fava beans or taking certain medications. Experts also note that long-standing advice to avoid the pain medication Optalgin solely because of G6PD deficiency is no longer considered universally necessary.

One patient illustrated the importance of questioning established diagnoses. A Canadian woman sought a second opinion in Israel after living for nearly 30 years believing she had common variable immunodeficiency (CVID), a primary immune disorder.

Her life revolved around avoiding infection, and she rarely left home without wearing a mask. Rather than simply repeating routine tests, doctors conducted a comprehensive multidisciplinary evaluation.

The conclusion was unexpected: she had never had CVID. But correcting the diagnosis was only the first step. Decades of believing herself chronically ill had profoundly affected her life, requiring time and careful support to rebuild confidence and adjust to a new reality.

Researchers caution that many immune mechanisms remain poorly understood, and not every patient responds to targeted therapies. Nevertheless, the rapid progress in immunology is fundamentally changing medical practice.

By focusing on the biological processes driving disease rather than on diagnostic labels alone, physicians are developing more personalized treatments and, in many cases, achieving results that would have been impossible just a decade ago.

As scientists continue to unravel how immune cells communicate and how common pathways link different diseases, experts believe even more innovative therapies, and renewed hope for patients with previously difficult-to-treat conditions, are likely to emerge.