indium-oxine and Fever-of-Unknown-Origin

With a current annual mortality rate of around 35% worldwide, infection remains a significant concern, and the diagnosis and localization of infectious foci is an important health issue. As an established infection-imaging modality, nuclear medicine plays a vital health-care role in the diagnosis and subsequent effective treatment of this condition. Despite the development of several newer radiopharmaceuticals, (67)Ga and leukocyte imaging procedures have maintained their established place for infection. Several techniques in nuclear medicine significantly aid infection diagnosis, including imaging with (111)In-oxine-, (99m)Tc-hexamethylpropyleneamine oxime-, and (99m)Tc-stannous fluoride colloid-labeled leukocytes and with (67)Ga-citrate. Each radiopharmaceutical has specific advantages and disadvantages that make it suitable to diagnose different infectious processes (e.g., soft-tissue sepsis, inflammatory bowel disease, osteomyelitis, occult fever, fever of unknown origin, and infections commonly found in immunocompromised patients). After finishing this article, the reader should be able to identify the properties of an ideal radiopharmaceutical for infection imaging, list a range of available infection-imaging radiopharmaceuticals, compare the relative results of a range of radiopharmaceuticals used internationally to detect infection in the body, understand several common infectious processes that can be diagnosed using nuclear medicine techniques, and select an appropriate radiopharmaceutical to image a range of infectious processes.

Topics: Citrates; Fever of Unknown Origin; Gallium; Humans; Infections; Irritable Bowel Syndrome; Leukocytes; Nuclear Medicine; Organometallic Compounds; Osteomyelitis; Oxyquinoline; Practice Patterns, Physicians'; Predictive Value of Tests; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Sepsis; Technetium Compounds; Technetium Tc 99m Exametazime; Tin Fluorides; Tomography, Emission-Computed

Investigators have used various techniques and radionuclides such as 51Cr and 32P-diisofluorophosphate to label blood cells and to study cell survival. Early studies also used these radionuclides to label human leucocytes for cell survival by in-vitro counting. But external imaging could not be done with these agents. Starting with the use of the gamma-emitting radionuclide (111)In-oxine for in-vitro labelling of phagocytic leucocytes, external imaging became possible. This method was the basis of visualisation of cell distribution within the body. Because an abscess consists primarily of leucocytes, leucocytes labelled with (111)In localise within the abscess and are detectable by imaging. Nowadays other radiopharmaceuticals with other underlying uptake mechanisms are also used to detect inflammatory or infectious foci in patients. Nuclear medicine can be most useful in patients with fever of unknown origin, where a focus has to be defined, or in patients where a lesion is known by clinical symptoms or by a radiological imaging and the differentiation between infection and other pathologies has to be made.

Topics: Fever of Unknown Origin; Fluorine Radioisotopes; Gallium Radioisotopes; Humans; Indium Radioisotopes; Infections; Inflammation; Leukocytes; Nuclear Medicine; Organometallic Compounds; Oxyquinoline; Radioimmunodetection; Radiopharmaceuticals; Technetium Tc 99m Exametazime

Radiolabeled blood cells are widely used for both clinical and research studies. In vitro and in vivo studies have shown the tagging process does not significantly affect function. The labeling techniques and clinical uses of labeled leukocytes and platelets are reviewed.

Topics: Abscess; Blood Platelets; Cerebrovascular Disorders; Chromium Radioisotopes; Eosinophils; Fever of Unknown Origin; Graft Rejection; Humans; Hydroxyquinolines; Indium; Isotope Labeling; Leukocyte Count; Leukocytes; Lymphocytes; Organometallic Compounds; Oxyquinoline; Pulmonary Embolism; Radioisotopes; Radionuclide Imaging; Thrombophlebitis; Tropolone

Radionuclide techniques for localizing inflammatory processes had relied heavily upon 67Ga-citrate until McAfee and Thakur described the technique for the radiolabeling of leukocytes with 111In-oxine. Since their initial description in 1976 there has been continued development of the radiopharmaceutical, as well as clinical efficacy. At present 111In-labeled leukocytes continue to be handled as an investigational new drug but this has not greatly limited its clinical availability. Indium-111 leukocytes are the agent of choice for evaluation of patients with fever of unknown origin, osteomyelitis, and prosthetic graft infections; and preliminary data shows great promise in the area of detecting reoccurrence of inflammatory bowel disease. This article attempts to review currently accepted uses of 111In leukocytes as well as potential areas of application.

Topics: Abscess; Blood Vessel Prosthesis; Colitis, Ulcerative; Crohn Disease; Cytomegalovirus Infections; Enterocolitis, Pseudomembranous; Fever of Unknown Origin; Gallium Radioisotopes; Humans; Indium; Infections; Inflammation; Leukocytes; Liver Abscess; Organometallic Compounds; Osteomyelitis; Oxyquinoline; Pancreatic Diseases; Radionuclide Imaging

Technetium (99mTc) labelled, polyclonal human immunoglobulin (HIG) is a new agent that detects focal infection and inflammation. This new agent was compared in 40 patients with the accepted standard, namely 111In-oxine-labelled leucocytes. This comparison resulted in a sensitivity of 94% and a specificity of 96% for 99mTc-HIG when 111In-oxine leucocytes were defined as giving the true result. The new agent was shown to localize both sepsis and active inflammatory bowel disease (IBD). There was 100% concordance in the 16 patients with IBD who were imaged with both 99mTc-HIG and 111In-oxine leucocytes. Discordant results were obtained in one case of suspected osteomyelitis, which was false-positive on the 99mTc-HIG scan, and one case of pyrexia of unknown origin when the 99mTc-HIG was false-negative and the 111In-oxine leucocyte scan demonstrated accumulation of tracer in the caecum at 24 h post-injection. Normal distribution for 99mTc-HIG demonstrated activity in the kidneys and bladder and that 50% of the tracer is cleared through the kidneys during the first 24 h post-injection. There were no major or minor side-effects.

Topics: Bacterial Infections; Female; Fever of Unknown Origin; Humans; Immunoglobulins; Indium Radioisotopes; Inflammatory Bowel Diseases; Leukocytes; Male; Middle Aged; Organometallic Compounds; Osteomyelitis; Oxyquinoline; Radionuclide Imaging; Technetium

Four patients with the acquired immunodeficiency syndrome (AIDS) and fever were investigated using donor leucocyte scans. The lung/liver and lung/spleen uptake ratios in these patients were compared with the uptake ratios in donor leucocyte scans in seven neutropenic (non-AIDS) patients and five patients who had autologous leucocyte scans performed over the same time period. For all scans indium-111-oxime-labelled leucocytes were used, except for one AIDS patient in whom technetium-99m hexamethyl-propylene amine oxide (HMPAD)-labelled donor leucocytes were used. There were no adverse reactions to the donor cell infusions. Two patients had repeat studies 8 weeks apart (from different donors) without ill effect. There were no differences in the 111In uptake ratios between the three groups. There were three positive studies in the patients with AIDS, and these elucidated the cause of the pyrexia in all three. The negative case is more difficult to confirm, but the clinical course and the absence of focal disease on post-mortem have been taken to support the scan findings. There was no difference in the acceptability of the technique or the distribution of the labelled leucocytes between the AIDS and non-AIDS patients. Donor leucocyte imaging of patients with AIDS is probably more effective and considerably less hazardous for technical staff than autologous leucocyte methods. This study demonstrates that the technique can be applied successfully to patients with AIDS.

Topics: Acquired Immunodeficiency Syndrome; Adult; Aged; Bacterial Infections; Blood Donors; Fever of Unknown Origin; Humans; Indium Radioisotopes; Isotope Labeling; Leukocytes; Middle Aged; Opportunistic Infections; Organometallic Compounds; Organotechnetium Compounds; Oximes; Oxyquinoline; Radionuclide Imaging; Technetium Tc 99m Exametazime

In three patients with fever of unknown etiology, an Indium-111-Oxine WBC (White blood cell) scan was performed, in order to detect occult sites of inflammation. An intra-abdominal abscess was located in two cases, while in the third the negative result of the scan directed the diagnosis to other systemic pathologies.

Topics: Abscess; Adenocarcinoma; Adult; Aged; Aged, 80 and over; Colonic Neoplasms; Connective Tissue Diseases; Female; Fever of Unknown Origin; Humans; Hydroxyquinolines; Male; Middle Aged; Organometallic Compounds; Oxyquinoline; Radionuclide Imaging; Rectal Diseases

Indium-111 leukocyte scanning is a reliable means of locating acute infection in adults, but its use in the pediatric population has not been extensively documented. The results of scans on 30 children retrospectively reviewed are presented. Acute infections were detected in 15 of 16 patients (94% sensitivity) with one false negative scan. There were 8 truly negative and 6 falsely positive studies (57% specificity).

Topics: Adolescent; Child; Child, Preschool; Fever of Unknown Origin; Humans; Hydroxyquinolines; Indium; Infant; Infections; Leukocytes; Organometallic Compounds; Oxyquinoline; Radionuclide Imaging