HIV: 3 cases that hid in plain sight

CASE 1 › Roberta K, age 35, was referred by her family physician (FP) to a hematologist in November 2007 after her FP noted a platelet count of 63,000/mcL on a screening complete blood count (CBC; normal, 150,000-400,000/mcL). Ms. K also had asthma, hypothyroidism, depression, and migraine headaches. She was given a diagnosis of idiopathic thrombocytopenic purpura and started on oral prednisone. Her platelet count improved and she was maintained on prednisone 7.5 to 10 mg/d over the next 5 years with periodic dosage increases whenever her platelet count dropped below 50,000/mcL. She saw her FP for regular medical care 3 to 4 times a year and by a hematologist every 6 months.

In April 2012, Ms. K sought treatment from her FP for an acute painful rash consistent with herpes zoster involving the left C5-C6 dermatomes. Due to severe pain and secondary infection, she was admitted to the hospital. During the hospitalization, the inpatient team caring for her obtained a human immunodeficiency virus (HIV) serology, which was positive. Her only HIV risk factor was that she’d had 3 lifetime male sex partners.

The 3 patients described here illustrate a similar framing bias in that none of the physicians who cared for them in an outpatient setting perceived that their patient was at risk for HIV infection. Ms. K’s initial CD4+ T-cell count was 224 cells/mm³ (normal, nonimmunocompromised adult, 500–1,200¹) and her percentage of CD4+ T-cells was 21% (normal, 30%-60%²). Her HIV RNA level was 71,587 copies/mL; the goal of HIV treatment typically is to get this down to <200 copies/mL.  She was started on antiretroviral therapy (ART) consisting of fixed-dose emtricitabine/rilpivirine/
tenofovir (200 mg/25 mg/300 mg) and was weaned off prednisone. Six months after starting ART, her CD4+ T-cell count was 450 cells/mm³ and her HIV RNA level was <20 copies/mL. Her most recent platelet count was 148,000/mcL.

The correct diagnosis: Thrombocytopenia secondary to HIV infection.

CASE 2 › Christian M, age 40, presented to his FP in February 2010 with worsening cough and shortness of breath that he’d had for 4 weeks. He said he had unintentionally lost 20 pounds since the beginning of the year. He had no medical history of note, but had seen his FP on several occasions over the past few years for treatment of acute minor illnesses and an employment physical. He’d had no occupational exposures that might have affected his lungs, and he did not smoke.

He was initially diagnosed with bronchitis and treated with an oral antibiotic. Two weeks later, his symptoms persisted and Mr. M’s FP referred him to a pulmonologist. A chest x-ray showed an “interstitial process possibly consistent with pneumonia” for which the pulmonologist prescribed levofloxacin and oral prednisone for 10 days. At the follow-up visit, Mr. M had clinically improved. The diagnosis noted by the pulmonologist was “probably viral vs atypical pneumonia.”

Approximately 3 weeks later, in April 2010, Mr. M presented to the emergency department (ED) after several days of fever, cough, and worsening shortness of breath. A chest x-ray showed an interstitial pneumonitis that had worsened since the prior radiography. His pulse oximetry was 87% on room air.

A computed tomography (CT) scan of the chest revealed bilateral ground-glass opacities. The patient was admitted to the hospital and the next day underwent bronchoscopy with bronchoalveolar lavage. A Gomori methenamine silver stain for Pneumocystis jirovecii was positive, as was an HIV serology. Mr. M’s only reported risk factor for HIV was heterosexual contact. He had been in a stable relationship for over 14 years.

His baseline CD4+ T-cell count was 5 cells/mm³ (1%) and his HIV RNA level was >500,000 copies/mL. Several weeks later, Mr. M’s spouse tested positive for HIV. Her CD4+ T-cell count was 45 cells/mm³ (10%) and her viral load was 23,258 copies/mL. Although she was asymptomatic at the time of diagnosis, Ms. M was soon started on the same ART regimen as her husband.

The correct diagnosis: Pneumocystis pneumonia with symptoms of acquired immunodeficiency syndrome (AIDS) wasting syndrome.

Audiocast: HIV: Clues that are easy to missCASE 3 › Michael L, age 66, was seen by his FP in September 2010 for “preoperative clearance” for elbow surgery. He was in good health but had a platelet count of 67,000/mcL. For unclear reasons, the surgery was cancelled; Mr. L was supposed to be referred to a hematologist for the thrombocytopenia, but this consultation never occurred. The patient did not return to his FP until April 2012, when he complained of feeling “lightheaded and dizzy” for the past few weeks. His examination was remarkable only for mild orthostatic hypotension and he was diagnosed with “dehydration.”