Intestinal accumulation of 111In-granulocytes in patients studied because of occult infection

¹¹¹In-granulocyte scintigraphy was performed on 245 patients in whom a localized infection was suspected. In 123 patients scintigraphy was positive and of these 35 (28%) had intestinal accumulations of ¹¹¹In-granulocytes. Specific local causes for the intestinal uptake of radioactivity were antibiotic associated colitis (eight patients), local pyogenic bowel infection (four patients), systemic disease (two patients), bowel necrosis (two patients), colonic cancer (one patient) and Stevens-Johnson's syndrome (one patient). Nonspecific mechanisms of bowel accumulation were desquamation of labelled granulocytes (12 patients) and bleeding (two patients). In three cases the mechanism of colonic accumulation of granulocytes was not revealed. These results show that unexpected accumulations of labelled granulocytes in the gut is not a rare phenomenon and is often due to clinically significant intestinal inflammation or other disease, especially in patients who do not have signs of respiratory, pancreatic or oesophageal inflammation causing desquamated granulocytes to accumulate in the gut.     

No difference in sensitivity for occult infection between tropolone- and oxine-labeled indium-111 leukocytes

There is considerable disagreement as to whether oxine or tropolone is the best labeling agent for indium leukocytes. We have previously looked at the sensitivity of oxine-labeled 111In leukocyte scans for occult infections and now present a similar group of patients imaged with tropolone-labeled 111In leukocytes. Thirty-four patients (38 studies) with possible occult infection were prospectively studied. Patients were imaged 1-4 hr after injection and again at 24 hr postinjection. The early tropolone images had a sensitivity of 53% while the delayed images at 24 hr had a sensitivity of 93%. Based on a previous study, oxine-labeled leukocyte scans have an early sensitivity of 33% and a delayed sensitivity (at 24 hr) of 95%. The differences in sensitivity between oxine and tropolone when imaged early and at 24 hr were not statistically significant. We conclude that there is no significant difference in the ability to detect infection between oxine- and tropolone-labeled leukocytes, both early at 1-4 hr, and on delayed imaging 24 hr after injection.     

Decreased sensitivity of early imaging with In-111 oxine-labeled leukocytes in detection of occult infection: concise communication

Imaging with leukocytes labeled with indium-111 oxine is a sensitive technique for detecting sites of occult infection. Traditionally, imaging is performed 24 hr after injection. We undertook a prospective study of 35 patients (40 studies) with possible occult infection to see whether a 24-hr delay in imaging is really necessary. Patients were imaged at 1-4 hr and again at 24 hr after injection. The early images had a sensitivity of only 33%, compared with 95% for the 24-hr images. Of the seven studies that were positive on both early and delayed images, 71% had more intense uptake at 24 hr. There were no false-positive early images. We conclude that imaging 1-4 hr after injection with In-111 oxine-labeled leukocytes has a low sensitivity for detecting occult infection. However, a positive early image is specific for a site of infection.     

Intestinal transit studied with radiopaque markers in patients with multiple sclerosis]

The patients affected with multiple sclerosis (MS) often complain of constipation. This symptom is little tolerated by the patient; its etiology is still unknown. MS patients often have their movements impaired by disease progress, so that they have to sit down for a long time, or else they exhibit severe problems walking or moving. MS patients also present low intraabdominal pressure during voluntary contraction of abdominal wall muscles. In these patients, the authors suggest to study intestinal transit time by means of radiopaque markers. To this purpose, the radiological follow-up contributes to the setting of colorectal MS dysfunctions by daily controls of the progress of per os radiopaque markers, focusing on colonic transit time and temporary deposit areas. The results show high incidence of anorectal constipation. Thus, the examination can be considered a useful tool in the study of MS dysfunctions and an effective alternative to anorectal manometry.     

Pulmonary uptake in indium-111 leukocyte imaging: clinical significance in patients with suspected occult infections

A retrospective review was undertaken to evaluate the frequency and significance of pulmonary activity noted on 306 indium-111 leukocyte studies involving 232 patients with suspected occult infections. Forty-eight studies showed pulmonary activity in one of two patterns of uptake, focal or diffuse. Fourteen of 27 studies (52%) with focal uptake and two of 21 studies (10%) with diffuse uptake were associated with infectious processes. Lung uptake of indium-111-labeled leukocytes was a poor predictor of pulmonary infection in patients studied for occult infection, although the focal pattern was more likely than the diffuse pattern to be associated with infection.     

Detection of occult and intermittent rhinorrhea using 111In-DTPA

In an attempt to detect occult or intermittent rhinorrhea, 10 patients without and 9 cases with rhinorrhea were investigated after a lumbal injection of 1.3 mCi 111In-DTPA. Significant count rates were detectable in the nasal pledgets of all individuals, so that it was not possible to distinguish those with and those without rhinorrhea. Therefore, the ratio of activity in nasal pledgets and blood normalized for weight recommended by McKusick et al. was used. In the patients without evidence of rhinorrhea, the ratio did not exceed 2.0, whereas in 8 of the 9 cases with rhinorrhea, it was considerably increased. The detectability of rhinorrhea was increased by using more than one measurement and by provocation manoeuvres.     

Indium-111 leukocyte accumulation in intramuscular injection sites

We report four cases of indium-111 leukocyte concentration in previous intramuscular injection sites. Three patterns were observed: (1) small, discrete, and round; (2) linear; (3) irregular and large. The scintigraphic appearance did not necessarily correlate with the number of injections that the patient had received.     

Indium-111 leukocyte accumulation in intramuscular injection sites

We report four cases of indium-111 leukocyte concentration in previous intramuscular injection sites. Three patterns were observed: small, discrete, and round; linear; irregular and large. The scintigraphic appearance did not necessarily correlate with the number of injections that the patient had received.     

Intense accumulation of indium-111 leukocytes in peritonitis carcinomatosa

In order to detect the infectious foci in a case of terminal recurrent cancer of the sigmoid colon with intense inflammation, In-111 oxine leukocyte scintigraphy was performed. Leukocytes labeled with In-111 oxine quickly localized within the region of peritonitis carcinomatosa and could be imaged after 4 hours. With time, high activity appeared in this area. And 48 hours after injection, the large intestine was clearly seen. However, no activity was seen in the main recurrent tumor. This suggested that the labeled leukocytes had accumulated in regions of inflammation rather than in malignant tissue. When performing In-111 leukocyte scintigraphy for diseases in which tumor cells and inflammation are mixed, distinguishing the two components is particularly important, and time-sequential scanning is very useful.     

武威市某镇乙型肝炎感染者家庭内部隐匿性感染现状及其分子进化特征

 目的 研究武威市某镇乙型肝炎病毒(HBV)家庭内部感染者中隐匿性HBV感染(occult hepatitis B virus infection, OBI)的流行现状及其分子进化特征。方法 以2009年武威市某镇体检发现的HBsAg阳性者为先证者,询问其家族史,签署知情同意书后,对此家庭内部人员进行流行病学调查,收集血样。采用ELISA检测HBsAg、抗-HBs、HBeAg、抗-HBe、抗-HBc;对所有血清样本用病毒DNA磁珠法试剂盒提取,而后巢式PCR扩增S区获得HBVDNA片段,测序后应用mega6.0进行进化树分析。结果 共收集血清学标本80份;HBsAg、抗-HBc、HBVDNA的阳性率分别为43.8%、78.8%、37.5%;OBI共有12例,感染率是26.7%(12/45)。结论 在HBV感染家庭中,家庭内部OBI阳性率明显高于一般人群,基因型主要是C型、D型,其中基因型D型居多。     

Detection of occult infection following total joint arthroplasty using sequential technetium-99m HDP bone scintigraphy and indium-111 WBC imaging

Preoperative exclusion or confirmation of periprosthetic infection is essential for correct surgical management of patients with suspected infected joint prostheses. The sensitivity and specificity of [111In]WBC imaging in the diagnosis of infected total joint prostheses was examined in 28 patients and compared with sequential [99mTc]HDP/[111In]WBC scintigraphy and aspiration arthrography. The sensitivity of preoperative aspiration cultures was 12%, with a specificity of 81% and an accuracy of 58%. The sensitivity of [111In]WBC imaging alone was 100%, with a specificity of 50% and an accuracy of 65%. When correlated with the bone scintigraphy and read as sequential [99mTc]HDP/[111In]WBC imaging, the sensitivity was 88%, specificity 95%, and accuracy 93%. This study demonstrates that [111In]WBC imaging is an extremely sensitive imaging modality for the detection of occult infection of joint prostheses. It also demonstrates the necessity of correlating [111In]WBC images with [99mTc]HDP skeletal scintigraphy in the detection of occult periprosthetic infection.     

In-111-labeled leukocytes in the diagnosis of rejection and cytomegalovirus infection in renal transplant patients

Indium-111-labeled (In-111) leukocytes have been shown to be useful in the localization of inflammatory processes, including renal transplant rejection. Using previously reported labeling methods, 63 studies with this agent have been performed in 53 renal transplant patients. Indications for study included suspected rejection or cytomegalovirus (CMV) infection. Studies were performed in 33 men and 20 women, with ages ranging from 6 to 68 years. Autologous cells were normally used for labeling, although leukocytes obtained from ABO-compatible donors were used in three subjects. Rectilinear scanner and/or scintillation camera images were obtained at 24 hours after intravenous administration of 0.1 to 0.6 mCi of In-111-leukocytes. There was abnormal uptake of In-111-leukocytes in the transplanted kidney in 11 of 15 cases of rejection. In three additional cases of increased transplant uptake, CMV infection was present in two. Abnormal lung uptake was present in 13 of 14 patients with CMV infection. In four additional cases, increased lung uptake was associated with other pulmonary inflammatory disease. Increased lung activity was not seen in patients with uncomplicated transplant rejection. These results suggest that In-111-leukocyte imaging may be useful in the differential diagnosis of rejection versus CMV infection in renal transplant patients.     

Speed of accumulation of 111In-labelled granulocytes in focal non-osseous inflammatory processes

Using a method of 111In-oxine granulocyte labelling in diluted plasma, we performed 162 scintigraphic studies in 159 patients with suspected non-osseous infection. We obtained a positive predictive value of 82%, and a negative predictive value of 97%, i.e. the method is very sensitive, albeit less specific. Sequential imaging showed around 50% of the scintigrams to turn positive at 30 min after the injection, the most rapid accumulation being seen in cases of superficial soft tissue infections and in pulmonary and pleural infections, cerebral abscesses showing a rather sluggish accretion of activity, urinary tract infections, abdominal abscesses and bowel inflammation accumulating activity at an intermediate rate. Our results indicate that the described method is sensitive, and that the sequential scintigraphic approach allows an early diagnosis in most cases, and facilitates the interpretation of delayed scans.     

Preparation of 111In-DTPA morpholino oligomer for low abdominal accumulation

An ability to quantitate the beta cell mass by noninvasive nuclear imaging will be very useful in the prevention, diagnosis, and treatment of diabetes. However, to be successful, radioactivity from the pancreas must not be obscured by the background radioactivity in the abdomen. Pretargeting offers the promise of achieving high target organ to normal tissue ratios. In preparation for pancreas imaging studies by pretargeting using morpholino oligomers (MORF/cMORF), it was necessary to develop a simple and efficient method to radiolabel the cMORF effector. Because we have shown that labeling the cMORF with ¹¹¹In via DTPA reduces excretion into the intestines compared to labeling with ^99mTc via MAG₃, the conjugation of DTPA to cMORF was investigated for ¹¹¹In labeling. The amine-derivatized cMORF was conjugated with DTPA using 1-ethyl-3(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) as an alternative to the conventional cyclic anhydride. The conjugation efficiency (represented by the number of DTPA groups attached per cMORF) was investigated by changing the EDC, DTPA, and cMORF molar ratios. Different open columns were considered for the purification of DTPA–cMORF. Before conjugation, each cMORF molecule was confirmed to have an amine by trinitrobenzene sulfonic acid (TNBS) assay using the ω-amino butyric acid as positive standard and the non-amine derivatized cMORF as negative standard. The average number of DTPA groups per cMORF was 0.15–0.20 following the conjugation over a cMORF/DTPA molar ratio of 0.5–5 and over a cMORF/EDC molar ratio of 20–60. The conjugation efficiency was lower than expected probably due to steric hindrance. A 1×50 cm P-4 column using ammonium acetate as eluting buffer provided an adequate separation of DTPA–cMORF from free DTPA. The ¹¹¹In labeling efficiency by transchelation from acetate exceeded 95%, thus avoiding the need for postlabeling purification. Despite the lower than expected conjugation efficiency in which no more than one-fifth of the cMORF were DTPA-derivatized, a specific radioactivity of at least 300 μCi/μg or 1.90 Ci/μmol of cMORF was achieved. In conclusion, a protocol is described for ¹¹¹In-DTPA–cMORF that provides the high specific activity favorable to beta cell imaging because of the low mass fraction of beta cells in pancreas (1–2%) and obviates the need for postlabeling purification.     

Indium-111-labeled leukocyte scintigraphy in hemodialysis access-site infection

Bacterial sepsis, a significant complication of chronic hemodialysis, is generally the result of infection at the vascular access site. We retrospectively reviewed the utility of indium-111-(111In) labeled autologous leukocyte scintigraphy in 26 patients (30 scans) with synthetic vascular grafts, on chronic hemodialysis, in whom hemodialysis access site infection was a diagnostic consideration. Leukocyte scintigraphy correctly identified all fifteen access-site infections; there was one false-positive study, for an overall sensitivity and specificity of 100% and 93%, respectively. Of particular significance is the fact that in nine (60%) of the fifteen access-site infections, physical examination was normal. Our data indicate that 111In-labeled leukocyte scintigraphy is a useful procedure for the diagnosis of hemodialysis access-site infection, and it is especially valuable when physical examination of the access site is normal.