Interaction of the immunosuppressant deoxyspergualin with a member of the Hsp70 family of heat shock proteins.

Deoxyspergualin (DSG) is a potent immunosuppressant whose mechanism of action remains unknown. To elucidate its mechanism of action, an intracellular DSG binding protein was identified. DSG has now been shown to bind specifically to Hsc70, the constitutive or cognate member of the heat shock protein 70 (Hsp70) protein family. The members of the Hsp70 family of heat shock proteins are important for many cellular processes, including immune responses, and this finding suggests that heat shock proteins may represent a class of immunosuppressant binding proteins, or immunophilins, distinct from the previously identified cis-trans proline isomerases. DSG may provide a tool for understanding the function of heat shock proteins in immunological processes.

Genetic characteristics of the HeLa cell.

The genotype of the patient Henrietta Lacks from whose cervical carcinoma the HeLa cell was derived was deduced from the phenotypes of her husband and children, and from studies of the HeLa cell. Hemizygous expression of glucose-6-phosphate dehydrogenase in HeLa, together with the deduced heterozygosity of Mrs. Lacks, is consistent with clonal origin of her neoplasm.

The nonerythropoietic component of early bilirubin.

The early labeled bilirubin consists of two primary components. The more rapidly synthesized of the two is independent of erythropoiesis (nonerythropoietic), whereas the second fraction is related to red cell production (erythyropoietic). The present studies concern the origin of the nonerythropoietic component. The nonerythropoietic, early labeled bilirubin was studied in bile fistula rats with (delta ALA)-4-(14)C delta aminolevulinic acid and glycine-2-(14)C as precursors. That nephrectomy did not reduce the size of this component despite the large and rapidly turning over pool of renal heme suggests that this pool may be of minor importance in its production. Intoxication with lead to a level that reduced hepatic heme synthesis was associated with a decrease in early bilirubin formation. The synthesis of this bilirubin was assessed in animals with phenobarbital-induced heme protein and cycloheximide-suppressed protein synthesis. Rats pretreated with phenobarbital at a dose level of 60 mg/kg with induction of cytochrome P-450 synthesis showed a minor increase in early labeling when glycine-2-(14)C but not when delta ALA-4-(14)C was used as precursor. Rats given cycloheximide at a dose level that markedly reduced hepatic protein and cytochrome P-450 synthesis but allowed heme synthesis to continue at 60% of its pretreatment level synthesized normal or increased amounts of early bilirubin from delta ALA-4-(14)C. Allylisopropylacetamide intoxication caused little change in early bilirubin formation, whereas aminotriazole given at a time after maximal hepatic heme labeling produced a small but significant increase in the appearance of labeled bilirubin. These findings indicate that early bilirubin production is little influenced by increased hepatic porphyrin synthesis or by changes in the rapidly turning over heme protein P-450. A minimal increase attends catalase inactivation by aminotriazole. Normal or increased synthesis takes place in the presence of suppression of protein synthesis. This finding suggests that the nonerythropoietic early bilirubin may itself consist of two subcomponents. The first of these may arise from free tissue heme or its precursors, and the second may derive from the turnover of the heme proteins. The first subcomponent may serve as a regulatory mechanism for the removal of heme synthesized in excess of its protein acceptor. A composite scheme is proposed for the origin of the total early bilirubin from heme compartments in tissue and marrow.

Impaired culture generated cytotoxicity with preservation of spontaneous natural killer-cell activity in cartilage-hair hypoplasia.

Recent studies of cartilage-hair hypoplasia (CHH), a form of short-limbed dwarfism, have shown that all affected individuals have a cellular proliferation defect that results in a cellular immunodeficiency. However, only a minority of CHH individuals suffer from severe, life-threatening infections. For this reason, relevant immune defense mechanisms that may be responsible for maintaining intact host defenses in the majority of CHH individuals were studied. Spontaneous and allogeneic culture-induced (mixed lymphocyte response-MLR) specific and nonspecific (NK-like) cytotoxic mechanisms were analyzed and correlated with lymphocyte subpopulations present in CHH and normal individuals. Spontaneous natural-killer (NK) activity was present at or above normal levels, but culture-induced specific cytotoxicity and NK-like cytotoxicity as well as NK-like activity by T cell lines were significantly reduced in CHH individuals. The generation of radiation-resistant cytotoxicity, which normally occurs during allogeneic MLR, was markedly diminished in CHH, and was correlated with the decreased proliferation observed in CHH cultures. Preservation of spontaneous NK activity and loss of all forms of culture-induced cytotoxicity was associated with an increase in the proportion of lymphocytes bearing a thymic independent NK phenotype (OKM1+ OKT3- Fc gamma + low-affinity E+), and a significant decrease in thymic derived OKT3+ cytolytic T cell sub-populations in CHH individuals. Therefore, an intact cellular cytotoxic effector mechanism has been identified in CHH (i.e., NK activity). Natural cytotoxicity may be of importance in maintaining host resistance to viral infections despite diminished thymic-derived effector mechanisms in cartilage-hair hypoplasia.

Inherited incomplete deficiency of the fourth component of complement (C4) determined by a gene not linked to human histocompatibility leukocyte antigens.

We have studied a family in which the proband had systemic lupus erythematosus and selective incomplete deficiency of the fourth component of complement (C4) (2-5% of the normal level). An additional six healthy family members also had low C4 levels (2.4-24.1% of normal) but no evidence of lupus. This form of inherited C4 deficiency differs from that in previously reported families in that inheritance was autosomal dominant (rather than recessive), C4 levels were markedly reduced (but not undetectable), and there was no linkage to HLA, BF, or C4 structural loci, all known to be within the major histocompatibility complex.

High rate of discordance between clinical and autopsy diagnoses in blood and marrow transplantation.

We analyzed autopsies performed in a Canadian blood and marrow transplantation (BMT) program. We aimed to assess variables that predict the performance of an autopsy, whether rates of autopsy are changing, and the rate of discordance between clinical and autopsy diagnoses. All deceased adult patients from January 1990 to December 2004 were reviewed. Autopsy rates were compared to a large teaching hospital. Of 476 myeloablative BMT patients, 225 died and 48 (27%) underwent autopsy. Autopsy was more likely in patients dying: <100 days post-BMT, in the intensive care unit, after allografting, and on weekends. Autopsy rates among BMT patients declined during the three time periods (1990-1994, 1995-1999, 2000-2004). The autopsy rate at the teaching hospital showed a similar downward temporal trend. Major and minor disagreements at autopsy were present in 16 (34%) and 14 (30%) of cases, respectively. There was no change in discordance rates over time. Thus, despite advances in diagnostic procedures, high levels of disagreement between clinical and autopsy diagnoses for BMT patients persist as autopsy rates decline. We recommend that the autopsy regains its role as a valuable investigation. This may become especially relevant in an era where patients with medical comorbidities are undergoing reduced-intensity BMT.

The level of expression of the rat growth hormone gene in liver tumor cells is at least eight orders of magnitude less than that in anterior pituitary cells.

Rat liver hepatoma cells (HTC) which express liver-specific gene products were assayed for the expression of the rat growth hormone (rGH) gene, which is normally expressed in anterior pituitary somatotrophs. The combination of immunoprecipitation and two-dimensional gel electrophoresis provided a highly sensitive assay for rGH synthesis at levels as low as one part in 10(9) of cell protein synthesis (or four molecules of rGH per cell). No rGH expression was detected at this level. The lack of expression in HTC cells did not derive from a deletion of the rGH gene, as shown by Southern hybridization analysis of genomic DNA. Because the gene is expressed at greater than 30% of anterior pituitary protein synthesis, differentiation regulated rGH expression by over 10(8)-fold between the two cell types. Additionally, DNA-excess solution hybridization was used to measure the level of rGH mRNA sequences. A novel and general method for preparing single-strand probes from recombinant plasmids was developed. Hybridization analyses with a sensitivity of detection of 1 part in 10(8) failed to detect any rGH RNA sequences in either the nucleus or cytoplasm of HTC cells. It is concluded, therefore, that the restriction in rGH expression in the liver tumor cells is likely to occur at the level of the transcription of the gene, and that for all practical purposes, the rGH gene is completely shut off in the hepatoma cells.

Augmentation of natural killer cell activity by lipopolysaccharide through separable effects on the binding of nonadherent lymphocytes to tumor targets and tumor killing.

A single-cell assay was utilized to study the augmentation by Escherichia coli lipopolysaccharide (LPS) of the cytotoxicity of human lymphocytes for the human myeloid tumor K562. Preincubation with LPS at 20 micrograms/ml for 30 min at 37 degrees increased the binding of all nonadherent (NA) lymphocyte populations to K562 tumors [unseparated NA lymphocytes from 13.1 to 25.1%, immunoglobulin G Fc receptor-enriched lymphocytes from 27.6 to 42.9%, and immunoglobulin G Fc receptor-depleted lymphocytes from 14.0 to 23.7%, at p less than 0.001]. In contrast, interferon (IFN) at 10 units/ml had no effect on the overall binding of lymphocytes to K562 tumors. When lymphocyte-tumor conjugates were dispersed in agarose, cytotoxic activity of unseparated NA lymphocytes at 1 to 3 hr was markedly increased by preincubation with LPS (p less than 0.001). However, LPS did not enhance cytotoxicity if conjugates were formed in its absence. IFN, likewise, increased cytotoxic activity in unseparated NA lymphocytes at 1 to 3 hr (p less than 0.001). No synergistic cytotoxicity was seen with concurrent exposure to LPS and IFN. LPS increased cytotoxicity in the Fc receptor-enriched:tumor conjugates at 1 to 3 hr (p less than 0.001) and appeared to promote more efficient killing in individual conjugates over time. Cytotoxicity in the Fc receptor-depleted:tumor conjugates was not enhanced by LPS. Thus, LPS may enhance natural killer cell-like activity by increasing the binding of human lymphocytes to K562 tumors and by rearranging the population of binding cells to include more efficient killer cells. While the effects of LPS on binding appear independent of IFN, selective recruitment of more efficient killer cells could be through an IFN mechanism.

Inhibition of antibody response to Pseudomonas exotoxin and an immunotoxin containing Pseudomonas exotoxin by 15-deoxyspergualin in mice.

Immunotoxins are potent cell-killing agents that may be useful in the treatment of cancer. The early production of neutralizing antibodies to immunotoxins is one of the major limiting factors for their use in humans. 15-Deoxyspergualin (DSG), a derivative of spergualin, which is a metabolite of Bacillus laterosporus, has been found to have immunosuppressive activity in rodents, dogs, and primates. We examined the suppressive activity of DSG on the antibody response to Pseudomonas exotoxin in mice by enzyme-linked immunosorbent assay. Male BDF1 mice were immunized with a single dose of a nontoxic mutant of Pseudomonas exotoxin (40 micrograms) and then treated with i.p. injections of DSF at a dose of 10 mg/kg for 3 days. Although antibodies to Pseudomonas exotoxin were observed within 7 days in the control group, there was complete suppression of antibody production in the DSG-treated group. Immunosuppression has also been observed in animals immunized with multiple doses (10 mg x 7 d) of Pseudomonas exotoxin and treated with DSG at a dose of 5 mg/kg for 21 days. Similar immunosuppression was observed in mice given multiple doses of the immunotoxin, anti-Tac-LysPE40. We conclude that the immunosuppressive activity of DSG may be useful in increasing the duration of immunotoxin treatment.

Cytotoxic therapy-induced D-xylose malabsorption and invasive infection during remission-induction therapy for acute myeloid leukemia in adults.

PURPOSE: To study the sequential changes in the intestinal absorption of an oral pentose probe, D-xylose, in patients receiving therapy for untreated acute myeloid leukemia (AML), and to correlate these changes to infectious morbidity. PATIENTS AND METHODS: Serial D-xylose absorption studies were conducted in 110 consecutive adult patients admitted to a university-affiliated tertiary care hospital for remission-induction therapy for untreated newly diagnosed AML. Serial serum D-xylose levels were obtained 1 hour after a 5-g oral dose of D-xylose at baseline and weekly for 4 weeks until marrow recovery. These results were correlated with invasive infection using multivariate techniques. RESULTS: The mean (+/- SEM) serum D-xylose levels were 0.88 +/- 0.03, 0.69 +/- 0.03, 0.58 +/- 0.02, 0.53 +/- 0.02, and 0.73 +/- 0.02 mmol/L at baseline and weeks 1 to 4, respectively (P < .0001, analysis of variance [AN-OVA]). Time to malabsorption varied with induction regimen (P = .007, log-rank test). Bloodstream infections during week 2 correlated with malabsorption (P = .007). Neutropenic enterocolitis correlated independently with induction regimen (P = .009), malabsorption at week 2 (P = .02), and the development of candidemia (P = .005). Hepatosplenic fungal infection correlated with induction regimen (P = .03), malabsorption at week 2 (P = .02), and fever at diagnosis (P = .003). Malabsorption was unrelated to the duration of severe neutropenia and the administration of parenteral nutrition. CONCLUSION: Serial D-xylose absorption studies in subjects with AML produced a characteristic profile of cytotoxic therapy-related damage to the functional integrity of the intestinal epithelium that was regimen dependent, myelosuppression independent, and predictive for invasive infectious complications. Further study to validate these observations appears warranted.

Therapy of untreated acute myeloid leukemia in the elderly: remission-induction using a non-cytarabine-containing regimen of mitoxantrone plus etoposide.

PURPOSE: The University of Manitoba Adult Acute Leukemia Study Group sought to examine the safety, efficacy, and impact on quality of life of a non-cytarabine-containing remission-induction regimen followed by intermediate-dose cytarabine (IDARA-C) postremission therapy for the management of untreated acute myeloid leukemia (AML) in patients age 60 to 80 years. PATIENTS AND METHODS: Eligible patients received mitoxantrone 10 mg/m2 and etoposide 100 mg/m2 on days 1 to 5. Complete remitters received a single course of cytarabine 0.5 mg/m2 every 12 hours on days 1 to 6. Cytogenetic and immunophenotyping studies were performed at diagnosis and were examined for prognostic importance. The Functional Living Index-Cancer (FLI-C) was used in the longitudinal assessment of quality of life. RESULTS: A total of 37 (55%) of 67 eligible patients achieved remission, 34 (92%) of whom did so with a single course. The induction mortality rate was 12%. The median disease-free and overall survival times were 8.4 and 9.2 months, respectively. CD34 stem-cell phenotype, poor performance status, and high cytogenetic complexity score were independent covariates of failure to achieve remission. Very complex karotype combined with CD34 stem-cell phenotype to predict induction death in 67% of cases (P = .0003). Cytotoxic therapy-related gut epithelial damage was maximal during weeks 2 and 3 of therapy. Complete remitters and partial responders exhibited significantly improved global FLI-C scores following completion of therapy. CONCLUSION: Mitoxantrone plus etoposide was an effective and well-tolerated first-line induction regimen for AML in the elderly that should be studied further in comparison to the standard cytarabine/anthracycline-based therapy.

Antibody response to pneumococcal polysaccharides in insulin-dependent diabetes mellitus.

Twenty-one insulin-dependent diabetics and 11 healthy control children were immunized with polyvalent pneumococcal polysaccharide vaccine. Serum antibody to pneumococcal polysaccharides was measured by radioimmunoassay before and after immunization. Although there were some differences in type-specific antibody concentrations between diabetic and control subjects, the overall antibody concentrations preimmunization, 3-4 wk postimmunization, and 6-7 wk postimmunization were similar in both populations. In both groups antibody response to immunization correlated strongly with preimmunization antibody concentration. Among the diabetic subjects there was no correlation between antibody responses and duration of disease, insulin dose, or concentration of glycosylated hemoglobin. Insulin-dependent diabetic subjects have a serum antibody response to pneumococcal polysaccharides equivalent to that of controls, and in both populations the magnitude of the antibody response correlates with preimmunization antibody levels.

In vivo regulation of hemopoiesis by transforming growth factor beta 1: stimulation of GM-CSF- and M-CSF-dependent murine bone marrow precursors.

Injection of mice with either natural bovine bone-derived or human recombinant transforming growth factor beta 1 (TGF-beta 1) resulted in a significant increase of the macrophage and macrophage-granulocyte-forming capacity of their macrophage colony-stimulating factor (M-CSF)- and granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent bone marrow precursor cells. The increased potential for generating granulocytes and/or macrophages from bone marrow cells of mice injected with TGF-beta 1 was associated with an increase of the number of M-CSF- and GM-CSF-dependent bone marrow colony-forming units (CFU). The effect was selective, in that in vivo applied TGF-beta 1 did not affect interleukin 3 (IL-3)-dependent CFU. The data suggest that TGF-beta may be useful in recovery of bone marrow granulocyte- and macrophage-forming potentials following depletion caused by chemo- or radiotherapy.

T cell-specific human alloantisera-detecting antigens segregating outside the major histocompatibility complex.

Two sera demonstrated non-HLA lymphocytotoxicity on the basis of reactivity with the cells of siblings genotypically identical to the serum donors for the major histocompatibility complex. These two sera, Bl and Caf, once contaminating HLA antibodies were removed by absorption with pooled platelets, demonstrated allogeneic lymphocytotoxicity that was restricted to T lymphocytes. Reactivity of the absorbed sera segregated independently of the major histocompatibility complex in 3 of 12 families tested. Unlike both cold lymphotoxins and HLA antibodies, the absorbed sera showed little temperature sensitivity against allogeneic cells, although reactivity of the Bl serum to autologous cells and to cells of the donor's HLA identical sibling did show a decrease with increasing temperature and restriction of activity to the 19S-containing fraction. Granulocytes were unreactive with the absorbed sera. Such sera may provide probes of minor transplantation antigens or markers, or both, of lymphoid subpopulations.

Polymorphic radiation sensitivity of human natural killer activity: possible role of DNA strand breakage.

Natural killer (NK) activity of human mononuclear cells is sensitive to inhibition by radiation, under the control of polymorphic X linked genes. In order to define the mechanism of this inhibition, we have evaluated the ability of treatments known to damage DNA to inhibit NK activity. The alkylating agents streptozotocin (SZ) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) were potent inhibitors of NK activity. Further, a specific competitive inhibitor of adenosine diphosphoribosyl polymerase (ADPRP), 3-aminobenzamide, was able to prevent inhibition by gamma-radiation, UV radiation, and the two alkylating drugs, SZ and MNNG, suggesting the ADPRP, known to be activated by DNA strand breakage, mediates the inhibition by these treatments. NK activity of radioresistant subjects was somewhat more resistant to inhibition by SZ or UVR when compared to radiosensitive NK activity but neither of these treatments gave the clear phenotypic distinction of gamma-radiation, suggesting that chemical strand breakage does not precisely model gamma-radiation and also that the mechanism of UVR inhibition may differ from that of gamma-radiation. These results indicate a role for activation of ADPRP in the inhibitory effect of UV and gamma-radiation on human NK activity and suggest that the biochemical basis for polymorphism in the sensitivity of NK activity to gamma-radiation will be found in the sensitivity to ADPRP activation or the level of activation of this enzyme, known to be the key to DNA repair.

Radioresistance of culture-induced augmented natural killer-like activity.

Human NK activity is radiosensitive under the control of X-linked genes. We have evaluated the expression of these genes in other forms of cellular cytotoxicity. The NK radioresistant and radiosensitive phenotype is expressed in ADCC. Specific cellular cytotoxicity, generated in a MLC with a radiosensitive donor as responder, was radioresistant. NK-like activity recruited from nonadherent cells of radiosensitive subjects stimulated with allogenic cells, mitogens (PHA, Con A or PWM), or recall antigens (TT or PPD) was radioresistant. The acquisition of radioresistance was relatively rapid, beginning within 24 hr after exposure to PHA, prior to detectable proliferation. Radioresistance of MLR augmented NK-like activity was maximal 3 days after initiation of the culture. MLR augmented NK-like activity was spared by the immunosuppressive polypeptide antibiotic CsA at doses up to 1 micrometer/ml. CsA did, however, reduce acquisition of radioresistance by the NK-like activity at doses above 0.01 mu gm/ml, a concentration which does not inhibit uptake of 3H-thymidine but does reduce the level of specific CML. These data suggest that mitogens and antigens, including allogeneic cells, are recruiting radioresistant NK-like activity which can be distinguished from the radiosensitive spontaneous NK activity of the cell donor. Further, in the MLR, both radiosensitive and radioresistant NK-like activity may be recruited.

Lymphocytes of persons with the acquired immunodeficiency syndrome and related conditions express reactivity with the monoclonal antibody 4D12 reflective of in vivo lymphocyte activation.

We observed that lymphocytes obtained from healthy persons generally expressed infrequent reactivity with the monoclonal antibody 4D12, an antibody raised against a cell line infected by the human T-lymphotropic virus type I. As had been observed previously, persons bearing HLA-B5 cross-reactive antigens and certain other allotypes had frequent lymphocyte reactivity with 4D12. Lymphocytes obtained from persons infected by the human immunodeficiency virus were highly reactive with 4D12 as were lymphocytes obtained from persons with other viral or bacterial infections. Flow cytometric studies revealed greater 4D12 reactivity by larger lymphocytes, and in vitro studies demonstrated that lectin-stimulated lymphocytes acquired 4D12-reactive antigens. There was also a significant correlation between expression of 4D12-reactive antigens and the presence of the interleukin-2 receptor as recognized by the monoclonal antibody anti-Tac. Thus, the monoclonal antibody 4D12 recognizes a lymphocyte surface antigen frequently expressed among persons with various acute and chronic infections. This antigen is a marker of lymphocyte activation.

Natural cytotoxicity in immunodeficiency diseases: preservation of natural killer activity and the in vivo appearance of radioresistant killing.

We studied spontaneous natural killer (NK) cell activity and radiation-resistant NK mediated cytotoxicity in four patients with clinically documented severe combined immune deficiency disease (SCID), and in one subject each with intestinal lymphangiectasia and cartilage-hair hypoplasia. We observed the preservation of spontaneous NK activity in all patients despite the presence of profound B- and T-lymphocytopenia and clinical immunodeficiency. NK activity was associated with relatively normal circulating numbers of OKM1+ lymphocytes, a population known to contain NK effectors. Spontaneous NK activity resistant to 3000 rad was increased in all patients, indicating the presence of activated natural killer cells in vivo. The concept of a chronically activated immune system in these patients was further supported by the presence of increased Ia positive T cells in all subjects tested, suggesting that radioresistant NK activity may be a useful parameter to measure when assessing in vivo immune activation. Our data, as well as that of others, supports the hypothesis that at least one population of NK cells is a distinct lineage arising at the differentiation level of myeloid and lymphoid stem cells in the bone marrow.

Alterations in hepatic heme and cytochrome P-450 metabolism in Murphy-Sturm lymphosarcoma-bearing rats. Implications for drug metabolism.

Previous studies have shown that tumor-bearing rats have significantly decreased hepatic microsomal cytochrome P-450 content and NADPH-cytochrome c reductase activity with, consequently, significantly decreased capacity for microsomal oxidative drug metabolism. Subsequent investigations have revealed that the rates of hepatic cytochrome P-450 apo-protein synthesis and degradation are decreased significantly and hepatic microsomal heme oxygenase activity is increased significantly in rats bearing an extra-hepatic tumor. Further studies have been done to attempt to clarify the pathogenesis and significance of these observations. Hepatic delta-aminolevulinic acid (ALA) synthetase activity in male Wistar rats declined to a nadir of 162 +/- 34 (S.E.) pmoles ALA per mg protein per 30 min 6 days following i.m. transplantation of Murphy-Sturm lymphosarcoma (vs control = 218 +/- 36 pmoles per mg per 30 min). Turnover of 3H-labeled heme in microsomal CO-binding particles (i.e. cytochrome P-450 heme) was increased significantly 8 days following i.m. transplantation of Murphy-Sturm lymphosarcoma with a T 1/2 of 5.5 hr for the fast phase of hepatic cytochrome P-450 heme disappearance in tumor-bearing rats as compared with a T 1/2 of 7 hr in control rats. Hepatic cytochrome P-450 apo-protein concentration was slightly, but not significantly, increased in Murphy-Sturm lymphosarcoma-bearing rats as compared with control rats up to 10 days following tumor transplantation. These results suggest that, in Murphy-Sturm lymphosarcoma-bearing rats, decreased microsomal cytochrome P-450 concentration is the result of both decreased cytochrome P-450 apo-protein synthesis and increased cytochrome P-450 heme turnover. Apo-cytochrome P-450 concentration was not appreciably altered because increased cytochrome P-450 heme turnover and decreased cytochrome P-450 apo-protein degradation were balanced by decreased cytochrome P-450 apo-protein synthesis. Because of their effects on cytochrome P-450 concentration and action, these alterations in heme and hemoprotein metabolism may be of importance in regulating oxidative drug metabolism in the tumor-bearing state.

'Reverse crescent pattern' on SPECT brain perfusion scan in chronic subdural hematoma.

A SPECT brain perfusion scan was performed on a patient who had symptoms of dementia. The SPECT scan showed marked crescentic medial displacement of the left cerebral hemisphere ("reverse crescent pattern"), and mildly decreased cortical perfusion in the affected hemisphere. Crossed cerebellar diaschisis was not present. On x-ray CT, the underlying abnormality was found to be a unilateral chronic subdural hematoma causing a significant mass effect. A reverse crescent pattern without crossed cerebellar diaschisis on SPECT brain perfusion scan in patients with dementia may suggest the diagnosis of chronic subdural hematoma.