Medical literature has described the concurrent presence of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and human immunodeficiency virus (HIV) infection in a single patient, although these cases are exceedingly rare.
HIV care has undergone a revolution of sorts in recent decades, especially with the introduction of pre-exposure prophylaxis, which reduces the risk of HIV infection during unprotected intercourse. Perhaps the most striking change in HIV care remains changing attitudes toward the disease since the height of the HIV health scare in the 1980s, during which misinformation was rife.
Today, with the widespread availability of advanced drugs, both prophylactic and therapeutic, HIV can be said to be functionally curable in individuals in the sense that the presence of the virus is so insignificant as to not pose a health threat to one’s sexual partner.
Patients with HIV can now expect to have near-normal life expectancy. Of course, the world is hungry for a definite cure, and research indicates that we are getting closer by the day. However, the longer life expectancy of patients with HIV today also makes the eventual presence of comorbidities more likely, such as kidney disease, which can pose a significant systemic health challenge to individuals with this condition.
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Concurrent HIV and AAV Diagnosis
In BMC Nephrology, Vornicu and colleagues presented the case study of a patient with HIV who was also diagnosed with AAV. A 29-year-old woman presented to the nephrology department with acute kidney injury and nephrotic syndrome with active urinary sediment. She had been experiencing renal deterioration for the previous 6 weeks. She had a medical history of well-controlled HIV on ritonavir, darunavir, and raltegravir.
Upon physical admission, her general status was altered and she had pitting edema. A chest auscultation revealed diminished breath sounds in the lung base. Her oxygen saturation was 92%. Laboratory investigations revealed anemia (6.2 g/dL), as well as raised serum creatinine (503.8 µmol/L) and urea (45.78 mmol/L). She had metabolic acidosis with a serum bicarbonate of 12.4 mmol/L.
Her urinalysis was positive for erythrocytes (127 cells/µL); 24-hour proteinuria was 7 g, and serum albumin was 2.4 g/dL. Immunological screening was positive for ANCA, with a titer of antimyeloperoxidase antibody of 52.4 IU/mL. Complement C3 fraction was low at 67 mg/dL.
The patient’s physicians proceeded to conduct a percutaneous ultrasound-guided kidney biopsy. They observed 5 globally sclerosed glomeruli, while the functional glomeruli presented fibrocellular crescents, with evidence of fibrinoid necrosis. Interstitial fibrosis and tubular atrophy were observed.
“There were also signs of acute tubular injury with a simplification of the tubular epithelium with intraluminal cellular detritus and a tubulointerstitial mononuclear infiltrate,” the authors wrote. “Electron microscopy showed diffuse foot process effacement and no dense deposits.”
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A computed tomography (CT) was performed, revealing alveolar infiltrates that were suggestive of diffuse alveolar hemorrhage. Together, these findings were sufficient for a diagnosis of AAV with renal and pulmonary involvement. She was started on immunosuppressive therapy (cyclophosphamides, rituximab, and tapering corticosteroids), which resolved the diffuse alveolar hemorrhage and induced immunological remission.
The patient received trimethoprim-sulfamethoxazole prophylaxis for Pneumocystis pneumonia. No infectious complications were reported during immunosuppressive therapy.
AAV in the Context of HIV
“Most of HIV studies were conducted in the preantiretroviral therapy era with a population of patients presenting at a more advanced disease stage,” Vornicu et al wrote, “But in the last ten years, systematic investigations have started to appear with the purpose of describing the prevalence of autoantibodies in the antiretroviral therapy era when a higher proportion of patients have a good immunovirological status.”
This means that the link between diseases such as AAV and HIV can now be investigated in earnest in the era of modern HIV therapeutics. Although research on HIV in the past was primarily focused on extending survival and reducing stigma attached to the disease, studies today have more room to explore how HIV interacts with other comorbidities.
There are some prominent theories regarding how HIV relates to autoimmune conditions such as AAV. Scientists hypothesize that autoimmune phenomena may be modified by therapies used to treat HIV; there are suggestions that highly active antiretroviral therapy (HAART) may quicken the onset of autoimmune disorders. This is based on research suggesting that immune reconstitution inflammatory syndrome may occur secondary to the prescription of HAART.
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As mentioned, the combination of AAV and HIV is exceedingly rare, estimated to be present in less than 1% of individuals with HIV. However, rheumatic disorders are still sometimes characterized in patients with HIV; these include granulomatosis with polyangiitis, polyarteritis nodosa, and cutaneous vasculitis. The treatment for these comorbidities are similar to that prescribed to the patient in this case study: a bout of immunosuppressive therapy, typically including cyclophosphamide and corticosteroids.
The patient in this case study had significant kidney disease, which is a common manifestation in patients with HIV. However, it is rarely linked to small vessel vasculitis: a study involving 60 renal biopsies of patients with acute kidney injury among HIV-positive patients found not a single case of small vessel vasculitis.
“In conclusion, although it is not clear whether HIV infection and AAV are causally or coincidentally related, the possibility of this systemic autoimmune phenomenon should be acknowledged by physicians to establish the correct diagnosis and treat the disease accordingly,” the authors wrote.
References
Vornicu A, Obrișcă B, Sorohan B, Berechet A, Ismail G. ANCA-associated vasculitis in a HIV-infected patient: a case-based review. BMC Nephrol. 2023;24(1):210. doi:10.1186/s12882-023-03244-9
Vali PS, Ismal K, Gowrishankar S, Sahay M. Renal disease in human immunodeficiency virus – not just HIV-associated nephropathy. Indian J Nephrol. 2012;22(2):98-102. doi:10.4103/0971-4065.97117
