Is NSIP Contagious or Cancer? What Patients Should Know

The short answer is no. Non-specific interstitial pneumonia (NSIP) itself is not cancer, and it is not a contagious infection you can catch from or pass on to someone else ^{[1] [2]}.

What Does “Pneumonia” Mean Here?

Because the word “pneumonia” is in the name, many people understandably assume it is an infection. In everyday language, “pneumonia” usually means an infection inside the air sacs of the lungs. However, in NSIP, the term simply describes a pattern of non-infectious inflammation and fibrosis (scarring) in the interstitium—the supportive connective tissue that surrounds the air sacs ^{[1] [2]}.

NSIP can occur without a known cause (idiopathic) or be associated with autoimmune conditions, where your immune system attacks your own body ^[3]. While NSIP itself is not cancer, it is possible for a person to have both conditions independently, and your doctor will continue to monitor your lung health ^[1].

The HIV Connection

You may read that NSIP is sometimes associated with HIV ^[4]. While it is true that NSIP has been reported in some people living with HIV, this does not mean NSIP is a virus. The exact reason for this connection is uncertain, but it is believed to be related to the immune system’s altered state ^[4].

People with compromised immune systems are also susceptible to opportunistic infections—infections that take advantage of a weakened immune system. A prime example is Pneumocystis jirovecii pneumonia (PJP), a fungal infection ^[5]. PJP is a true infection, whereas NSIP is not.

Infection Risk During Treatment

While you cannot pass NSIP to anyone, the treatments for it can make you more vulnerable to catching infections. Medications like corticosteroids, mycophenolate, or rituximab may be used in selected patients to suppress the immune system and reduce lung inflammation ^[6]. This immunosuppression can increase your risk of bacterial, viral, or fungal infections ^{[6] [7]}.

Infections Can Mimic Worsening NSIP

If you develop a respiratory infection while on immunosuppressants, the symptoms can look and feel remarkably similar to a sudden worsening (acute exacerbation) of your NSIP ^{[8] [9]}.

On a CT scan, both an infection and an NSIP flare can cause similar or overlapping findings, such as ground-glass opacities (cloudy spots on the imaging) ^{[10] [11]}. Because imaging alone cannot reliably distinguish between an infection and an NSIP flare, your medical team will likely need to evaluate the clinical context and perform additional testing—such as blood cultures, respiratory viral testing, or sometimes a bronchoscopy—to see what is happening ^[9].

Clinicians will also evaluate for other urgent causes of sudden breathlessness, such as a blood clot or heart issues ^[8]. Doctors may start you on antimicrobial treatments while waiting for test results, while carefully managing your immunosuppressant doses. Do not start, stop, or change your medication doses without your doctor’s guidance ^[12].

When to Seek Medical Care

An acute exacerbation of NSIP, an infection, or other complications can all cause sudden breathing difficulties. You should follow an individualized action plan from your doctor outlining your specific oxygen thresholds and when to call.

Tip: Always keep an up-to-date medication list (including the dates of treatments like rituximab) and inform urgent care staff immediately that you have interstitial lung disease and are taking immune-suppressing medications.

Go to the emergency room or call emergency services if you experience:

• Severe breathlessness at rest or an inability to speak in full sentences ^[13]
• A sudden drop in oxygen levels below your doctor’s prescribed target, or blue lips ^{[14] [13]}
• Chest pain, confusion, or fainting ^[13]
• A rapid deterioration in your breathing over hours or days ^{[15] [8]}

Contact your clinic the same day for assessment if you notice:

• A new fever, chills, or night sweats (note: a serious infection can sometimes occur without a fever when you are taking immunosuppressive medications) ^{[16] [7]}
• A new or worsening cough, or a change in your sputum ^[16]
• A gradual increase in how out of breath you feel with your normal activities ^[17]