Patients with HIV infection and fever: a diagnostic approach

[Infections and fever]

Fever can be due to infectious or noninfectious causes and results from the body's natural response to exogenous or endogenous pyrogens. Laboratory tests including complete blood count, differential blood count, C‑reactive protein, erythrocyte sedimentation rate and procalcitonin do not have sufficient sensitivity and specificity to definitively detect or rule out an infectious (bacterial, viral, parasitic) cause of fever. Blood cultures should be carried out when bacteremic or septic illnesses are suspected. Fever is not always present in infections and can be absent, especially in older and immunocompromised patients. If fever is suspected, core temperatures should be taken, e.g., rectally, orally or invasively. Depending on the clinical situation, infectious causes must be excluded as the most likely cause of an acutely occurring fever. The investigation of long-standing fever (fever of unknown origin, FUO) can be complex and some infectious diseases should first be ruled out, whereby a syndromic classification often helps to clarify the cause of the fever.

Etiologies of fever of unknown origin in HIV/AIDS patients, Hanoi, Vietnam

BACKGROUND

Fever of unknown origin (FUO) is a challenge for clinicians treating patients with HIV/AIDS. CD4 counts can be helpful in the diagnosis and treatment. This study aimed to determine several common etiologies of FUO stratified by CD4 count levels in HIV/AIDS patients.

METHODS

A cross-sectional retrospective and prospective study was conducted in 195 HIV/AIDS patients with FUO admitted to the National Hospital for Tropical Diseases from January 2016 to June 2019. Clinical parameters, immune status, and etiologies for each patient were recorded. Odds ratios were calculated to compare the distributions of common etiologies in groups with two different CD4 count levels: < 50 cells/mm3 and ≥ 50 cells/mm3.

RESULTS

The proportions of opportunistic infections and noninfectious etiologies were 93.3% and 3.6%, respectively. Tuberculosis was the most common opportunistic infection (46.7%), followed by talaromycosis (29.2%) and Pneumocystis jiroveci (PCP) infection (20.5%). Tuberculosis was predominant in all CD4 level groups. Most patients with talaromycosis had CD4 counts below 50 cells/mm3. In total, 53.8% of the patients were infected by one pathogen. The risks of tuberculosis and talaromycosis in FUO-HIV patients were high when their CD4 counts were below 50 cells/mm3.

CONCLUSIONS

Opportunistic infections, especially tuberculosis, are still the leading cause of FUO in HIV/AIDS patients. Tuberculosis and Talaromyces marneffei (TM) infection should be considered in patients with CD4 cell counts < 50 cells/mm3. This study implies that guidelines for appropriate testing to identify the etiology of FUO in HIV/AIDS patient based on the CD4 cell count should be developed, thereby reducing resource waste.

Autoimmunity and dysmetabolism of human acquired immunodeficiency syndrome

Acquired immunodeficiency syndrome (AIDS) remains ill-defined by lists of symptoms, infections, tumors, and disorders in metabolism and immunity. Low CD4 cell count, severe loss of body weight, pneumocystis pneumonia, and Kaposi's sarcoma are the major disease indicators. Lines of evidence indicate that patients living with AIDS have both immunodeficiency and autoimmunity. Immunodeficiency is attributed to deficits in the skin- and mucosa-defined innate immunity, CD4 T cells and regulatory T cells, presumably relating human immunodeficiency virus (HIV) infection. The autoimmunity in AIDS is evident by: (1) overproduction of autoantibodies, (2) impaired response of CD4 cells and CD8 cells, (3) failure of clinical trials of HIV vaccines, and (4) therapeutic benefits of immunosuppression following solid organ transplantation and bone marrow transplantation in patients at risk of AIDS. Autoantibodies are generated in response to antigens such as debris and molecules de novo released from dead cells, infectious agents, and catabolic events. Disturbances in metabolic homeostasis occur at the interface of immunodeficiency and autoimmunity in the development of AIDS. Optimal treatments favor therapeutics targeting on the regulation of metabolism to restore immune homeostasis.

Incidence and risk factors of fever in a contemporary cohort of HIV-patients with good access to antiretroviral therapy

OBJECTIVE

To study incidence and to determine risk factors of fever in a contemporary cohort of HIV-infected patients with access to antiretroviral therapy.

METHODS

Prospective study in a cohort of HIV-infected patients in Belgium from 2009 to 2013.

RESULTS

759 patients were followed for a total of 2136 patient years. The incidence of fever was low, with an incidence rate of 0.103 (95% CI 0.078; 0.135) febrile episodes per patient per year for temperature 38.3 °C or higher measured by a health care provider. Gender, age, ethnicity, and calendar year of measurement were no significant risk factors for fever in univariable analysis, but recent HIV diagnosis, prior AIDS, nadir CD4 cell count, last CD4 cell count, and viral load were, as were use of antiretroviral therapy, recent start of antiretroviral therapy and recent switch of antiretroviral therapy. Recent stop of antiretroviral therapy was no significant risk factor. In multivariable analysis prior AIDS, last CD4 and viral load remained significant risk factors, but use of antiretroviral therapy not.

CONCLUSION

In this contemporary cohort, incidence of fever was low but CD4 cell count less than 200/mm³ remained associated with the highest incidence of fever.

Clinical presentation, causes and outcome of febrile episodes in a prospective cohort of HIV-infected patients

BACKGROUND

Fever was frequently caused by opportunistic conditions in HIV-patients in the early years of the epidemic. Little is known about diagnostic spectrum and outcome of febrile episodes in patients with good access to antiretroviral therapy.

METHODS

We prospectively studied clinical presentation, diagnosis and outcome of febrile episodes in a contemporary cohort of HIV-patients with good access to antiretroviral therapy. Fever was defined as temperature 38.3 °C or higher, measured by a health care provider.

RESULTS

We found 220 febrile episodes in 146 patients. In 25.9% of episodes the patient had a CD4 less than 200/mm³ and in 78.6% the patient was on antiretroviral therapy. There were multiple episodes in 44 patients. A diagnosis was established in 91.8%. Infection accounted for 82.3%, mainly respiratory tract infections, viral syndromes and abdominal infections. Malignancy, drug reactions and inflammatory conditions accounted together for less than 12% of episodes. Fifteen percent were attributed to opportunistic conditions. Episodes in patients with CD4 less than 200 were less likely to be caused by infection, but more likely to be caused by malignancy, drug reactions and opportunistic conditions. In 6.4% the patient died within six months after the onset of fever. Risk factors for death at six months in multivariable analysis were higher age and lower CD4.

CONCLUSIONS

HIV-patients with access to antiretroviral therapy present with fever mostly due to conditions common in the general population. HIV-patients with low CD4 remain at risk for fever due to opportunistic conditions and death.