This document discusses a case of fever of unknown origin (FUO) in a young HIV-positive man with high viral load and low CD4 count. It provides definitions and classifications of FUO. The most common etiologies in HIV-positive patients are infections like atypical mycobacteria, and malignancies like non-Hodgkin's lymphoma. Diagnostic testing and biopsy of organs like the liver, lymph nodes, and bone marrow can help identify the cause. Positron emission tomography may also help locate sites of inflammation or malignancy. Therapeutic trials rarely establish a diagnosis for FUO. Polycythemia vera is a rare event in HIV patients, with only a few cases reported.

1. R 1 O S C A R M A L P A R T I D A T A B U C H I
H N G A I
FOD-HIV

2. Resumen
 Varón joven
 HIV+: CV alta, CD4 bajo y sin TARV
 Fiebre y pérdida de peso

3. FOD (FUO)
PETERSDORF RG, BEESON PB. Fever of unexplained origin: report
on 100 cases.
DEFINITION
●Fever higher than 38.3ºC on several occasions
●Duration of fever for at least three weeks
●Uncertain diagnosis after one week of study in the
hospital
*nosocomial, neutropenic, and HIV-associated

4. ETIOLOGY
 Three general categories of illness account for the
majority of "classic" FUO cases
●Infections
●Malignancies
●Connective tissue diseases (eg, vasculitis, rheumatoid
arthritis).

6. Geografía
 Estudios la mayoría realizados en países
desarrollados
 Tuberculosis, tifoidea, absceso amibiano hepático,
malaria, brucellosis, filariasis, schistosomiasis, kala
azar

7. Subpoblación
 AIDS — reflects the degree of immunosuppression
 In one series of 79 episodes of FUO HIV-positive patients with CD4
counts ranging from 0 to 790/microL and a median of40/microL,
 79% infections and 8 %malignancies; only 9 percent had no definite
diagnosis
 Over one-half mycobacteria, two-thirds atypical MAC. Only
lymphomas were highly represented in malignancies (NHL).
Disseminated Kaposi's sarcoma infrequent.
 As with FUO in HIV-negative patients, the country influences the
etiologies detected. In one study from Spain, for example, 137 HIV
patients bone marrow biopsy .The three most common diagnoses
were Mycobacteria (18 patients with M. tuberculosis and 14 with
MAC), non-Hodgkin lymphoma, and visceral leishmaniasis.

8. Diagnostic approach
 History and physical examination — A thorough
history should include the following information:
●Travel
●Animal exposure (eg, pets, occupational, living on a farm)
●Immunosuppression (with the degree noted)
●Drug and toxin history, including antimicrobials
●Localizing symptoms
The degree of fever, nature of the fever curve, apparent
toxicity, and response to antipyretics has not been
found to provide enough specificity to guide the
diagnosis of FUO

9. Diagnostic approach
 Diagnostic testing :
●Erythrocyte sedimentation rate or C-reactive protein
●Serum lactate dehydrogenase
●TST-IGRA
●HIV antibody assay and HIV viral load for patients at high risk
●Three routine blood cultures drawn from different sites over a
period of at least several hours
●Creatine phosphokinase
●Heterophile antibody test in children and young adults
●Antinuclear antibodies
●Serum protein electrophoresis
●CT scan of abdomen
●CT scan of chest

10. Biopsy
Critical modality in the directed (as opposed to screening) evaluation of FUO.
● Liver biopsy for possible miliary tuberculosis, granulomatous hepatitis, or other
granulomatous diseases such as sarcoidosis — liver biopsy was performed in seven
patients; it was helpful in one and false positive in three.
● Lymph node biopsy for possible malignancy, especially lymphoma node biopsy was
performed in 11 patients; it was helpful in five and false positive in three.
● Temporal artery to look for giant cell arteritis or biopsy of an affected tissue to diagnose
a vasculitis— temporal artery biopsy was performed in 14 patients; it was helpful in
one with no false positives.
● Pleural or pericardial biopsy in the evaluation of extrapulmonary tuberculosis.
● Bone marrow biopsy was performed in 19 patients; it was helpful in two and false
positive in one.
 In a retrospective review of 31 bone marrow biopsies obtained to evaluate FUOs at
a French tertiary hospital, occult hematologic malignancies were detected in 25
patients; lymphoma was detected in 19 patients, acute leukemia in four patients,
hairy cell leukemia in one patient, and multiple myeloma in one patient . Among those
with non-malignant causes, infections were detected in three patients, systemic
mastocytosis in two patients, and disseminated granulomatosis in one patient.
Thrombocytopenia and anemia strongly predicted a diagnostic biopsy.

11. Nuclear medicine
 F-fluorodeoxyglucose positron emission tomography
(FDG-PET) appears to be very sensitive in
identifying anatomic sites of inflammation and
malignancy. This modality may find a valuable place
in the evaluation of FUO. But data demonstrating
efficacy are needed..

13.  Therapeutic trials — Therapeutic trials of
antimicrobials or glucocorticoids, while tempting in
the effort to "do something," rarely establish a
diagnosis

14. Policitemia Vera-HIV
Sassaki MG, Souza CA, Siciliano RF, Leite AG, Padilha SL.
Polycythemia vera in a patient with the human immunodeficiency
virus: a case report. Braz J Infect Dis. 2000 Aug;4(4):204-7
 Evento raro, muy pocos casos reportados en
literatura científica.
 7 casos reportados
 No parecen estar asociados a mayor riesgo de
complicaciones que población general