Monoclonal antibody BA-1 does not bind to hematopoietic precursor cells

Monoclonal antibody BA-1 binds to B lymphocytes, to cells from most cases of non-T acute lymphoblastic leukemia (ALL), and weakly to neutrophils. To determine whether BA-1 also reacts with hematopoietic progenitor cells (HPC), we studied the effect of removal of BA-1+ cells from human bone marrow on the proliferation in vitro of the trilineage precursor cell CFU-GEMM, and on the committed progenitor cells of granulopoiesis (CFU-C) and erythropoiesis (BFU-E/CFU-E). Complement- mediated cytotoxicity using BA-1 at concentrations far beyond those required to lyse BA-1+ bone marrow cells and ALL cells did not result in inhibition of colony formation in any of the assays. A rosette separation method, using ox red blood cells coated with BA-1, resulted in enrichment of HPC in the BA-1-depleted interface, whereas very few HPC were found in the BA-1-enriched pellet. Both methods indicate that BA-1 does not bind to HPC, although binding of the antibody to the lymphohematopoietic stem cell cannot be excluded yet. The high cytotoxic capacity of the IgM antibody BA-1, and the lack of reactivity with HPC, make the antibody particularly suitable for use in autologous bone marrow transplantation for patients with ALL.     

Biallelic neutrophil Na-antigen system is associated with a polymorphism on the phospho-inositol-linked Fc gamma receptor III (CD16)

Neutrophils express two distinct types of receptor for the Fc region of IgG, FcRII and FcRIII, in amounts of 10,000 to 20,000 FcRII (40 Kd) and 100,000 to 200,000 FcRIII (50 to 80 Kd) per neutrophil. We showed that the FcRIII exhibits genetically determined heterogeneity, detectable by differences in electrophoretic mobility with sodium dodecyl sulfate (SDS) as well as by reaction with antibodies against the biallelic neutrophil-specific antigen system NA. FcRIII was precipitated with an FcRIII-specific monoclonal antibody (MoAb) from the neutrophils of 35 donors. NA1NA1 donors expressed an FcRIII with a molecular weight (mol wt) of 50 to 65 Kd, NA1NA2 donors expressed an FcRIII with a mol wt of 50 to 80 Kd, and NA2NA2 donors expressed an FcRIII with a mol wt of 65 to 80 Kd. Statistical analysis showed that the electrophoretic heterogeneity corresponds with the NA polymorphism (k = 1). Sequential immunoprecipitation with a MoAb against NA1 and a MoAb against anti- FcRIII, followed by SDS-polyacrylamide gel electrophoresis (PAGE), showed that NA1-FcRIII is distinct from NA2-FcRIII. Moreover, immunoprecipitation with a MoAb against NA1 yielded a protein of 50 to 65 Kd, and immunoprecipitation with human anti-NA2 sera or an MoAb against NA2 yielded a protein of 65 to 80 Kd. Preincubation of NA1NA2 neutrophils with F(ab')2 fragments of an MoAb against anti-NA1 reduced binding of IgG dimers to these cells with about 50%, whereas it completely prevented binding of the dimers to NA1NA1 neutrophils. Inhibition experiments with the MoAb against NA2 yielded the same results for NA1NA2 cells, whereas binding of IgG dimers to NA2NA2 cells was completely prevented. Thus, the products of both NA alleles bind IgG. Immunoprecipitation from the medium of neutrophils either stimulated with formyl- methionyl-leucyl-phenylalanine (FMLP) or treated with glycosyl-phosphatidyl-inositol-specific phospholipase C (GPI- PLC) showed that both the NA1-FcRIII and the NA2-FcRIII are released from the cell surface, indicating that both forms of FcRIII have some structural features in common. Deglycosylation of FcRIII from homozygous donors yielded material that showed several bands on SDS- PAGE. GPI-PLC treatment of neutrophils indicated that all of this material is phosphatidyl-inositol linked.     

Expression and structure of CD22 in acute leukemia

The purpose of this study was to examine the expression and structure of CD22 in B cell precursor acute lymphoblastic leukemia (BCP-ALL), acute myeloid leukemia (AML), and T cell acute lymphoblastic leukemia (T-ALL). By using immunofluorescence microscopy and flow cytometry we observed that CD22 is expressed not only in the cytoplasm (as previously reported) but also on the cell surface of virtually all (15/16) BCP-ALL examined. CD22 that was biosynthetically labeled with 35S-cysteine and immunoprecipitated from the uncommon cytoplasmic CD22- positive/surface CD22-negative BCP-ALL cells was analyzed by single- dimension sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Our results indicated that the cytoplasmic form of CD22 comigrated with 125I/lactoperoxidase-labeled surface CD22. Therefore, cytoplasmic CD22 is probably a pool of fully processed glycoprotein. We also observed unusual cases of AML (approximately 20%) that expressed cytoplasmic CD22 based on immunofluorescent staining; however, biosynthetic labeling and immunoprecipitation revealed an apparently cross-reactive protein(s) of approximately 250 to 300 kd in AML cells. No T-ALL cell lines examined expressed either cytoplasmic or surface CD22. Thus, cytoplasmic and surface expression of bona fide CD22 appears restricted to B cells, which suggests that this molecule subserves a function unique to B cells.     

Multiple sclerosis and systemic lupus erythematosus. Occurrence in two generations of the same family

Multiple sclerosis (MS) and systemic lupus erythematosus (SLE) have overlapping clinical features and laboratory findings. It has, in fact, been hypothesized that MS and SLE have a common etiology. Usually MS and SLE are considered to have autoimmune pathogenesis, and both are chronic diseases that can respond to steroids. Some patients are diagnosed with either MS or SLE but subsequently develop the other disease. We described a family where multiple members of one generation have SLE and two members of the preceding generation have MS. Histocompatibility typing did not reveal any association between HLA inheritance of genes and incidence of severity of disease.     

Splenosis--important differential diagnosis in splenectomized patients presenting with abdominal masses of unknown origin

A 40-year-old female patient was admitted for work-up of multiple abdominal masses. The lymphoma-mimicking tumors were detected accidentally during an ultrasound course. The past medical history was unremarkable besides a status post-traumatic splenic rupture and splenectomy. The patient was asymptomatic, especially there were no complaints of fever, night sweats or weight loss. Laboratory tests did not show pathological results. Ultrasound of the abdomen revealed multiple hypoechoic mesenterial and peritoneal enlarged tumors as well as a subhepatic mass (30 x 20 mm). Transmission computed tomography (CT) showed a normal chest, excluded abnormal thoracal masses and confirmed the multiple abdominal nodules. Microparticles were trapped only by tissue with phagocytosis function as cells of the reticulohistiocytary system in liver and spleen. Uptake of (99 m)Tc-labeled microparticles is specific for splenic tissue. All abdominal masses were detectable by single photon emission computed tomography (SPECT) after intravenous administration of this radiotracer. Ultrasound-guided biopsy proved the presence of spleen tissue with follicular hyperplasia. In conclusion, we report a case of post-traumatic splenosis. In 16 - 67 % of patients who experienced traumatic splenic rupture autotransplanted spleen tissue can be detected. Splenosis therefore is an important differential diagnosis of abdominal masses in splenectomized patients.     

Surgical removal of a distinct subcutaneous metastasis of multilocular hepatocellular carcinoma 2 months after initial percutaneous ethanol injection therapy

Subcutaneous tumor seeding after percutaneous ethanol injection therapy (PEI) for hepatocellular carcinoma is a rarely seen complication. It is reported due to needle track seeding during PEI after a distance of 6-46 months. Metastatic tumor spread is described subcutaneously, to the chest wall, abdominal wall and diaphragm. We report the case of a 76-year-old patient with chronic hepatitis B infection and cirrhosis which let to a multilocular hepatocellular carcinoma who underwent PEI. This patient developed 2 months after primary PEI a subcutaneous tumor formation confined to the right lower chest wall. Surgical tumor resection was performed. The histopathological evaluation confirmed subcutaneous seeding of the preknown hepatocellular carcinoma with a maximum of 30 mm in diameter. As a risk of PEI subcutaneous metastasis of the primary tumor should be considered even in early stage of therapy and close follow-up of the patient during treatment is required. Surgical tumor resection to ensure the curative intention of PEI is advisable.     

Sonographic criteria for the diagnosis of hepatic involvement in hereditary hemorrhagic telangiectasia (HHT)

Hepatic involvement in hereditary hemorrhagic telangiectasia (HHT) is highly variable and may lead to severe clinical symptoms such as heart failure. This controlled, prospective study defined sonographic criteria for hepatic involvement in HHT. Color Doppler sonography and pulsed Doppler sonography were used to study 25 patients with HHT and liver involvement, 20 patients with HHT without liver involvement, 25 patients with cirrhosis, and 25 patients without liver disease. The diagnosis of hepatic manifestation was confirmed by computed tomography and/or angiography. Liver size, parenchymal changes of the liver, vessel diameters, and flow velocities of the portal vein and the hepatic artery were determined. Resistance index (RI) and pulsatility index (PI) were calculated. The diameter of the common hepatic artery was significantly dilated without overlap between HHT patients with liver involvement and the 3 control groups (mean 11.3 +/- 2.8 mm [HHT with liver involvement], 4.6 +/- 0.9 mm [HHT without liver involvement], 4.8 +/- 1.0 mm [cirrhosis], and 4.4 +/- 1.0 mm [healthy controls], P <.001). Doppler parameters of the proper hepatic artery differed significantly (all P <.001). In all patients with HHT and liver involvement, areas with intrahepatic hypervascularization caused by dilated intrahepatic arteries were observed in varying intensity. Cardiac output significantly correlated with the diameter of the common hepatic artery (r = 0.53, P =.007) and the portal vein (r = 0.42, P =.05). In conclusion, the diameter of the common hepatic artery (>7 mm) and intrahepatic hypervascularization are suitable sonographic diagnostic parameters of HHT with high sensitivity and specificity. Dilated diameters of the hepatic feeding vessels are indicators for systemic circulatory distress in these patients.     

Fine needle sclerotherapy as a new effective therapeutic approach for nonparasitic splenic cysts: A case series

BackgroundNonparasitic splenic cysts are rare. Until now, surgical intervention has been the standard therapy of symptomatic splenic cysts.AimsWe herein present a retrospective analysis of an approach using percutaneous ultrasound-guided fine needle aspiration and sclerotherapy.MethodsOut of 88,151 ultrasound reports, we identified 138 patients who presented with splenic cysts. A single splenic cyst was found in 88% (mean size 28.9 mm). Twelve patients underwent percutaneous therapy of symptomatic splenic cysts. They were younger, had larger splenic cysts and more often cyst internal echoes than the 126 untreated patients (all p < 0.0001).ResultsInitial sclerotherapy was performed with polidocanol 1% in 9 patients and with NaCl 10% in 2 patients. One hemorrhagic cyst was only purged. Serious adverse events were not noted. Eight patients had to undergo 1–11 further percutaneous cyst therapies. 15 of these 30 reinterventions were cyst aspiration therapies, only, and 11 of them were sclerotherapies with NaCl 10%. Four patients were readmitted to hospital for cyst retreatment. After 57 ± 43 months of follow-up, cyst size significantly decreased (p < 0.0001). Only two patients had a complicated course of cyst therapy.ConclusionsPercutaneous ultrasound-guided sclerotherapy is a new approach for symptomatic splenic cysts. In most patients, cyst size and symptoms can be significantly reduced during one hospital stay.     

Two populations of CD56 (Leu-19)+/CD16+ cells in bone marrow transplant recipients.

Bone marrow transplant (BMT) recipients are severely immunocompromised during the early post-transplant period as their immune systems recapitulate. Among the first cells to repopulate the peripheral blood are natural killer (NK) cells. Studies in normal subjects have revealed that the majority of NK cells express CD16 and CD56 (Leu-19). Such NK cells express low density, dim, Leu-19 (Leu-19D+). A small percentage of high-density, bright, Leu-19 cells (Leu-19B+) which are CD16- have also been reported in normal subjects. In this study we observed that peripheral blood mononuclear cells (PBMC) from BMT recipients contained two distinct populations of Leu-19+ cells that co-expressed CD16 and these populations could be separated on the basis of differential Leu-19 and CD16 fluorescence intensities. Leu-19B/CD16D and Leu-19D/CD-16B cells were present in four of nine BMT patients studied. Cells from one BMT recipient with a very large expansion of the Leu-19B+ population (46% of PBMC by flow cytometry) were studied in detail. While this patient is not characteristic of all BMT recipients, the large number of Leu-19+ cells that could be isolated from him allowed extensive analysis of a previously unreported population of cells. Our data suggest that BMT recipients can be an important group of subjects to evaluate NK cell subsets as these cells mature and, presumably, differentiate in a regenerating immune system.