Frequency and Outcome of Graft versus Host Disease after Stem Cell Transplantation: A Six-Year Experience from a Tertiary Care Center in Pakistan

Combinatorial inhibition of Tec kinases BTK and ITK is beneficial in ameliorating murine sclerodermatous chronic graft versus host disease

Graft-versus-host disease (GVHD) is the major factor limiting the widespread use of potentially curative allogeneic hematopoietic stem cell transplant (allo-HSCT). Chronic GVHD is characterized by the activation of alloreactive donor immune cells, especially B- and T-cells, leading to tissue damage and pathogenic fibrosis. In this study, we used highly specific next-generation inhibitors of ITK (PCYC-274), BTK (PCYC-804), and ibrutinib-like BTK/ITK inhibitors (PCYC-914 and PCYC-401) in the B10.D2 → BALB/C model of murine sclerodermatous cGVHD. From the third week onward, allogeneic recipients in each group of respective Tec kinase inhibitors were treated three times weekly with inhibitors at doses of 10 and 30 mg/kg or with saline control via oral gavage. Overall, we found that selective BTK inhibition was less effective than combined ITK/BTK or ITK inhibition in lengthening survival and reducing symptoms of cGVHD. ITK inhibition was most efficacious, with PCYC-274 and PCYC-401 demonstrating a nearly 50 percent reduction in GVHD scoring even at the 10 mg/kg dose, while 30 mg/kg of these compounds almost completely ameliorated GVHD symptomology. BTK/ITK and ITK-treated mice showed significant reductions in overall pathology. Significant reductions in dermal thickness and fibrosis were shown for all treatment groups. There was evidence of mixed Th1 and Th2 cytokine profiles in the skin of mice with dermal cGVHD, as both IFN-gamma and IL-4 were upregulated in the allogeneic control group, while kinase inhibition significantly reduced levels of these cytokines. Using an in vitro model of T-cell polarization, Th1 cell production of TNF-alpha and IFN-gamma were partially blocked by ITK. Th2 cell production of IL-4 was almost completely blocked synergistically by ITK and BTK inhibition. BTK-specific inhibition was unable to block either Th1 or Th2 cytokine production. Taken together, these results confirm previous reports that ITK-focused inhibition inhibits Th1 and Th2 cells. Additionally, the compound's effects on T-cell proliferation were tested by CFSE assay. Pure ITK inhibition was most effective at blocking T-cell proliferation, with no proliferation in PCYC-274-treated cells even at 0.1uM. PCYC-401 and PCYC-914 showed some inhibition at lower doses, with complete inhibition evident at 10uM. PCYC-804 was only partially able to block proliferation even at 10uM. In conclusion, we observed substantial benefit for differential inhibition of Tec kinases in GVHD, with ITK being most efficacious and Th1 cells being more resistant to inhibition, matching the previously reported findings of a Th2 to Th1 selective pressure in cells treated with ibrutinib. Our data warrants the further development of ITK and ITK/BTK inhibitors with specific inhibitory ratios to improve the treatment of GVHD and other T-cell mediated diseases.

Evaluation of pulmonary complications in patients undergoing allogenic stem cell transplantation

Background

Mature blood cells can be differentiated from hematopoietic stem cells; thus, the latter can play a crucial role in maintaining defense against different microorganisms. Thus, hematopoietic stem cell transplantation is one of the most important lines of immunotherapy. Major systemic complications may occur post transplantation and could be fatal. Pulmonary complications include infectious and non-infectious complications. The aim of this study was to detect the pulmonary complications in allogeneic stem cell transplantation patients.

Results

We studied 20 patients after transplantation of allogeneic stem cells with regular follow-up in outpatient clinic of hematology department of Alexandria Main University Hospital. All the studied patients were subjected to history taking, plain x-ray chest PA view, CT chest, complete blood count, serum creatinine, liver enzymes, and serum cytomegalovirus (CMV) detection by antibodies IgG and IgM. Regarding sputum sampling, 7 patients’ samples (35%) were obtained either spontaneously or by induction via hypertonic saline 3%. One patient (5%) had miniBAL done, while bronchoalveolar lavage using fiber optic bronchoscopy was done for 2 patients (10%). Samples could not be obtained from the remaining patients. Samples were analyzed for culture for bacteria, Pneumocystis jiroveci using immunofluorescence test, CMV PCR, fungal culture, and smear for acid fast bacilli (AFB). Among the examined patients, 2 patients (20%) had pulmonary bacterial infection including streptococcus and multidrug-resistant strain of Klebsiella, 3 patients (30%) had pulmonary candida infection, and one patient (10%) had positive result of pulmonary CMV of low count which was considered insignificant. None of our patients had positive results for pulmonary tuberculosis nor Pneumocystis jiroveci. Six patients (30%) had CMV in serum; 3 patients (15.8%) had manifested CMV reactivation. One patient (5%) of our patients had pulmonary graft versus host disease GVHD. One patient (5%) had died during our study course within 12 days post-transplantation due to ARDS followed by multiple organ failure.

Conclusion

The prevalence of pulmonary infectious complications after allogenic stem cell transplantation was 50% of all studied patients, while 5% of the studied patients presented with non-infectious pulmonary complications.

Challenges in managing graft-versus-host disease in developing countries: a perspective

Hematopoietic cell transplant (HCT) activity is increasing worldwide due to safer techniques, widening indications, and more availability of donors. New HCT centers have recently been established in many developing countries including Asian and African countries. Due to limited resources, logistic, political, and social issues in developing countries, the treatment of orphan diseases like graft-versus-host disease (GVHD) can be challenging. We intended to delineate the current issues that institutions and clinicians face in managing GVHD. We conducted a comprehensive systematic electronic review of peer-reviewed published articles on GVHD management in developing countries. We used PubMed, Cochrane, and Embase databases as our primary source of data. Studies that were included described the treatments for both acute and chronic GVHD. Consensus on the use of high-dose methyl-prednisone and prednisolone as the initial therapy was widely accepted and used in practice. Socio-economic factors were found to be the major factor involved in GVHD management in lower income patients. Delayed diagnosis and treatment, lack of availability of healthcare professionals, lack of knowledge among cancer patients, and poverty are major concerns in the developing world. For optimal management, HCT programs should develop systems in place for long-term follow-up of HCT survivors and have a low threshold to initiate treatments for GVHD early. Awareness and health policy programs must be initiated at the grass-root level for long-term management of these survivors in developing countries.

Outcome of allogeneic hematopoietic stem cell transplantation in patients with hematological malignancies

INTRODUCTION

Allogeneic hematopoietic stem cell transplantation is a potentially curative treatment modality for hematological malignancies. We evaluated the outcome of patients suffering from hematological malignancies, including acute leukemias, chronic myeloid leukemia and myelodysplastic syndrome after allogeneic transplantation.

METHODS

All patients having hematological malignancies with HLA identical sibling donors who underwent allogeneic transplantation were included. Pre-transplant workup consisted of complete blood counts, evaluation of liver, kidneys, lungs, infectious profile, chest X-ray, paranasal sinus roentgenograms and dental review. Donors were given G-CSF at a dose of 5-10 μg/kg/twice daily for five days prior to harvest. The conditioning regimens included cyclophosphamide, busulfan and total body irradiation.

RESULTS

A total of 41 allogeneic transplants were performed for hematological malignancies from April 2004 to December 2012. There were 31 males and 10 females. Median age ± SD was 28 ± 11.7 years (range 8 - 54 years). A mean of 7.7×108±1.5 mononuclear cells/kg were infused (range:6.2-9.2×108/kg). The median time to white cell recovery was 19±4 days (range:15-23 days). Transplant related mortality was 19.5%. The median overall survival was 53.6 months. Overall survival at a median follow up of 37 months was 67%.

CONCLUSION

Allogeneic stem cell transplantation is an effective treatment option in patients with hematological malignancies. Our outcomes are comparable with results from neighboring countries as well as the western world.