Immune Disorders

HIV, lupus, anaphylaxis and transplant rejection

Med-Surg · Immune

HIV

Spread by blood, sex, and from parent to baby (pregnancy, birth, breastfeeding). Standard precautions are enough in care.
Testing: 4th-generation antigen/antibody test; viral load; CD4 count.
AIDS (stage 3): CD4 <200 cells/mm³ or an AIDS-defining infection or cancer.
Antiretroviral therapy for everyone with HIV, started as soon as possible; daily adherence prevents resistance.
Undetectable = untransmittable (U=U) by sex.

PrEP (prevention before exposure): daily pills, or long-acting injections (cabotegravir every 2 months; lenacapavir twice a year, approved 2025). New
PEP after exposure: start within 72 hours (sooner is better), take for 28 days.
Needlestick: wash with soap and water, report immediately, get evaluated for PEP.
Opportunistic infection prevention (e.g., TMP-SMX when CD4 <200); vaccines (no live vaccines if CD4 is low).
Pregnancy: ART throughout + infant prophylaxis prevents most transmission.

Systemic lupus erythematosus (SLE)

Autoimmune disease of many organs; mostly women of childbearing age.
Butterfly rash, sun sensitivity, joint pain, fatigue, fever, mouth sores, kidney disease (lupus nephritis), pleurisy or pericarditis.
Positive ANA (and more specific antibodies).
Hydroxychloroquine for nearly everyone (yearly eye exams), steroids for flares, immunosuppressants, belimumab, anifrolumab.
Sun protection; infection prevention; plan pregnancy when disease is quiet.

Anaphylaxis

Hives, swelling, wheeze, stridor, low BP, vomiting, sense of doom, within minutes of exposure.
Epinephrine IM first: 0.3–0.5 mg (1 mg/mL) in adults into the outer thigh; repeat every 5–15 min as needed.
Lay flat with legs up (sit up if struggling to breathe); oxygen; IV fluids; call for help.
Antihistamines and steroids are add-ons, not first-line.
Observe for a second (biphasic) reaction. Teach auto-injector use; nasal epinephrine spray is also available.
Latex allergy: cross-reacts with banana, avocado, kiwi, chestnut.

Transplant rejection

Hyperacute	Minutes to hours; graft removed
Acute	Days to months: fever, tenderness, falling organ function; treat with more immunosuppression
Chronic	Months to years: gradual loss of function

Lifelong immunosuppression (tacrolimus: drug levels, kidney toxicity, tremor; mycophenolate: birth defects, GI upset; steroids). Infection precautions, no live vaccines, sun protection and skin checks, no grapefruit with tacrolimus or cyclosporine.