Impact of active antibody‐mediated rejection treatment on donor‐specific antibodies in pediatric kidney transplant recipients

AMR is a major cause of graft loss after kidney transplantation. We evaluated a retrospective cohort of 13 pediatric kidney transplant patients diagnosed with active AMR. All 13 patients were treated with plasmapheresis (PP), IVIg, and rituximab. Anti‐HLA DSAs were measured at the time of transplantation, AMR diagnosis, 30 days post‐rejection treatment, 90 days post‐rejection treatment, and 24 ± 12 months post‐AMR. A total of 68 DSAs were identified from 13 patients at the time of active AMR diagnosis. The primary objective of this study was to differentiate treatment response rates between class I and class II anti‐HLA DSA post‐AMR treatment. Overall, DSAs were significantly reduced at 30 days, and the reduction was sustained at 90 days post‐treatment, even for class II anti‐HLA and strongly positive DSAs. A significant difference between class I and class II anti‐HLA DSA was observed at 30 days; however, between class significance was lost at 90‐day follow‐up due to continued class II anti‐HLA DSA treatment response. Low DSA strength was predictive of treatment response. eGFR demonstrated significant improvement 90 days after AMR diagnosis compared to the initial value at the time of AMR, and the effect was sustained for 12 months. These results suggest that the AMR treatment is effective in pediatric kidney transplant recipients with an early diagnosis of active AMR across both class I and class II anti‐HLA DSAs.     

Rapid diagnosis of invasive cytomegalovirus infection by examination of tissue specimens in centrifugation culture

Two hundred eight tissue specimens from 81 patients were examined by centrifugation culture for the rapid diagnosis of invasive cytomegalovirus (CMV) infection. Results were compared with those obtained by both conventional viral cultures and histologic examination. CMV was identified by centrifugation culture in 52 (25%) specimens at 16 hours after inoculation, including 39 lung specimens and 12 gastrointestinal specimens. One additional esophageal specimen was positive (53 of 208 specimens; 25.5%) at 36 hours. In contrast, CMV was recovered from only 50 of these 53 specimens by conventional cell culture at a mean of 11 days after inoculation. Forty-three of the 208 specimens (20.5%) were positive for CMV when examined by histologic methods, including light microscopy and tissue immunofluorescence. All 43 were positive by centrifugation culture. Specimens that were positive by centrifugation culture but negative by histologic methods included three lung specimens and seven gastrointestinal specimens. The technic of centrifugation culture is more sensitive for diagnosis of invasive CMV infection by the examination of affected tissue than either conventional viral culture or histologic technics, including tissue immunofluorescence, and more rapid than conventional culture or routine histologic examination.     

Granulocyte/macrophage colony stimulating factor. A potent activation signal for mature macrophages and monocytes

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a well-characterized hematopoietic growth factor. Recently, using purified recombinant-derived material, we have found that GM-CSF is also a potent activator of mature functional macrophages. Thus, we have found that exogenous GM-CSF augments the primary plaque-forming response to sheep red blood cells and that this effect is due to upregulation of Ia antigen expression and interleukin 1 production by the macrophages. We also show that GM-CSF inhibits the replication of Trypanosoma cruzi in cultured peritoneal macrophages and causes an accelerated clearance of Salmonella typhimurium from the peritoneal cavity of mice. These data indicate that GM-CSF is a multifunctional molecule stimulating both hematopoiesis and mature macrophage function.     

Seasonal exacerbation of eosinophilic esophagitis histologic activity in adults and children implicates role of aeroallergens

Background

Disease activity may correlate with environmental aeroallergen exposure in eosinophilic esophagitis. The association between seasons and flares of eosinophilic esophagitis (EoE) histologic activity has not been extensively studied.

Peripheral Immunotype Correlates with Minimal Residual Disease Status and Is Modulated by Immunomodulatory Drugs in Multiple Myeloma

Data indicate reversal of immune dysfunction with active treatment; however, the precise contribution of specific immune effector and immune suppressor components to achieve a minimal residual disease (MRD) state and immunomodulatory drug–mediated immunomodulatory effects in multiple myeloma (MM) patients remains poorly understood. In this prospective proof-of-principle study we sought to determine the dynamic alterations in natural killer (NK), NK-T, and T cells, including maturation and activating/inhibitory repertoire associated with MRD^pos versus MRD^neg status after autologous stem cell transplantation (ASCT) and during lenalidomide-based maintenance therapy. Of the 46MM patients enrolled, 36 had bone marrow MRD assessment 60+ days post-ASCT, 30 had longitudinal blood immunotyping during maintenance (pretherapy and after cycles 1, 3, and 6), and 20 had both MRD assessment and longitudinal immunotyping. Multicolor flow cytometry was used for MRD and immunotyping. Although the absolute number of NK cells was significantly lower in patients with MRD^pos response, phenotypically NK cells in these patients displayed higher expression of activating receptors KIRDS4 and decreased expression of inhibitory molecules NKG2A compared with the MRD^neg group. Furthermore, we observed significantly lower frequencies of T cells displaying KIR3DL1 in MRD^pos versus MRD^neg patients. Longitudinal immunotyping during lenalidomide maintenance showed loss of mature NK effector function, augmentation of NK-T effector function, and acquisition of PD1 independent anergic state. Our findings also suggest skewing of T cells toward an exhausted state during the maintenance phase in MRD^pos patients. Put together, these observations provide a distinctive signature for MRD^neg and MRD^pos groups. These data support exploration of immune profiling in prospective clinical trials according to MRD-defined responses to identify patients that may benefit from maintenance intensification/modification or maintenance withdrawal.     

Quality control in human in vitro fertilization

The implementation of suitable quality control (QC) is not only required for the accreditation of a human in vitro fertilization (IVF) laboratory, but is also fundamental to its success. Several assays have been employed to screen culture media and contact supplies. The suitability of one assay in particular, the mouse embryo assay (MEA), has been questioned over the years. Here we discuss how the conditions of such an assay, together with the stage of embryonic development used, have a profound effect on the outcome of the assay. Furthermore, by assessing embryos at multiple time points during the preimplantation period (rather than simply determining blastocyst formation), together with quantitating key parameters such as blastocyst cell number, it is possible to identify suboptimal components of a culture system. As well as identifying those components that result in outright embryonic demise, under the appropriate conditions the MEA can detect components that lead to impaired development. It is proposed that under the appropriate conditions, the MEA is a useful adjunct to quality control in human IVF, but several assays used in concert are better than a single test.     

A 3 year retrospective review of intrauterine insemination, using cryopreserved donor spermatozoa and cycle monitoring by urinary or serum luteinizing hormone measurements

Insemination with donor spermatozoa is an integral part of infertility treatment. For the last 3 years in our unit, intrauterine insemination with donor spermatozoa (IUID) has been used in preference to vaginal insemination. In this retrospective study, patients were offered an initial course of five single intrauterine inseminations with cryopreserved donor spermatozoa and treatment was then reviewed. A total of 389 patients received 1465 inseminations. In all, 1119 cycles were monitored using luteinizing hormone serum analyses and 346 cycles using the urine home test kits. The clinical pregnancy rate per insemination for the cycles monitored by the serum assay was 18.0% (202/1119) compared with the urine cycles (13.7%, 46/346) (P <05). The pregnancy loss rate was not significantly different (14.4%, 29/202 and 21.7%, 10/46) (serum and urine cycles respectively). The viable clinical pregnancy rate was significantly higher (P <03) for the serum cycles than for the cycles using the urinary monitoring (15.5%, 173/1119 and 10.4%, 36/346 respectively). The cycles monitored by serum assay had a significantly higher cumulative viable clinical pregnancy rate (P <0001) of 70.2% after nine inseminations compared with the urine monitored cycles of 54.8%. The majority of patients opted for the serum cycles, with a minority self-selecting the urine cycles mainly for travelling convenience. The explanation for the significant differences between the viable clinical pregnancy rates per insemination and the cumulative viable clinical pregnancy rates may be due to the sensitivity of the urine home test kit or the patients' interpretation of the result.      

B lymphocytes secreting IgG linked to latent transforming growth factor- beta prevent primary cytolytic T lymphocyte responses

B lymphocytes secreting IgG linked to latent transforming growth factor (TGF)-beta (IgG-TGF-beta) prevent cytolytic T lymphocyte (CTL) responses to unrelated antigens in mixed lymphocyte cultures (MLC) so long as resting resident macrophages and functional Fc receptors are present. This was shown using IgG-secreting plaque-forming cells (PFC) to sheep erythrocytes (SRBC) obtained from popliteal lymph nodes of mice injected repeatedly in foot pads with SRBC. Remarkably, as few as approximately 300 PFC prevented CTL responses of 5 x 10(5) normal syngeneic spleen cells in MLC. Supranatants of short-term cultures of PFC also prevented CTL responses, and suppression was prevented by eliminating or dissociating IgG and TGF-beta present in supranatants or by antibody against active TGF-beta. Furthermore, the latency- associated peptide of latent TGF-beta was detected in approximately 10% of foci of IgG captured from single PFC, indicating that at least some B lymphocytes secrete IgG-TGF-beta as a complex. Resting resident macrophages (which do not produce latent TGF-beta) and functional Fc receptors were required for suppression, consistent with idea that IgG- TGF-beta is taken up through Fc receptors for IgG and that active TGF- beta, cleaved from latent TGF-beta of the complex, is delivered directly to potentially responding CTL. If CTL responses in man are similarly regulated by B lymphocytes, then an ongoing B cell response in patients with chronic viral infections or bearing immunogenic cancers may prevent effective therapeutic vaccination.