Autoimmune Thyroiditis Induced by Bartonella henselae (Cat-Scratch Disease) Might Be Reversible.

INTRODUCTION: Bartonella henselae infection leads to development of cat-scratch disease (CSD) but may also trigger of autoimmune thyroiditis (AIT). CASE PRESENTATION: We describe a 4-year-old boy with a severe fever of unknown etiology, disseminated neck lymphadenopathy, and a headache. Treatment with antibiotics was employed, but finally a left tonsillectomy, selective left lymphadenectomy, and immunophenotyping were performed to exclude lymphoma. Histologic examination excluded lymphoma but revealed CSD. IgG against B. henselae and Bartonella quintana was positive. A goiter was also found and positive anti-thyroid antibodies confirmed AIT. Two months later, the thyroid was not palpable, normal on ultrasound, and both anti-thyroid antibodies were negative. The full reversibility was documented, and 6-year follow-up showed that the patient remains disease free. CONCLUSION: This is the first report that AIT triggered by B. henselae/B. qunitana might be reversible if the pathogenetic factor is eliminated at an early stage of disease.

Successful Treatment of Large B-Cell Lymphoma in a Child with Compound Heterozygous Mutation in the ATM Gene.

Ataxia-telangiectasia (AT) is a multisystemic neurodegenerative inborn error of immunity (IEI) characterized by DNA repair defect, chromosomal instability, and hypersensitivity to ionizing radiation. Impaired DNA double-strand break repair determines a high risk of developing hematological malignancies, especially lymphoproliferative diseases. Poor response to treatment, excessive chemotherapy toxicities, and the need for avoiding exposure to ionizing radiation make the successful clinical management of patients with AT challenging for oncologists. We describe the favorable outcome of the LBCL with IRF4 rearrangement at stage III in a 7-year-old female patient diagnosed with AT. The patient was treated according to the B-HR arm of the INTER-B-NHL-COP 2010 protocol, including the administration of rituximab, cyclophosphamide, methotrexate, prednisone, etc. She presented excessive treatment toxicities despite individually reduced doses of methotrexate and cyclophosphamide. However, in the MRI there was no significant reduction in pathologic lymph nodes after three immunochemotherapy courses. Therefore, a lymph node biopsy was taken. Its subsequent histopathological examination revealed tuberculosis-like changes, though tuberculosis suspicion was excluded. After two following immunochemotherapy courses, PET-CT confirmed complete remission. From March 2022 onwards, the patient has remained in remission under the care of the outpatient children's oncology clinic.

Relationship between Gd-IgA1 and TNFR1 in IgA nephropathy and IgA vasculitis nephritis in children - multicenter study.

AIM OF THE STUDY: To evaluate the relationship between serum Gd-IgA1 (sGd-IgA1) and serum and urine TNFR1 (sTNFR1, uTNFR1) levels as possible prognostic factors in IgA nephropathy (IgAN) and IgA vasculitis nephritis (IgAVN). MATERIAL AND METHODS: From 299 patients from the Polish Registry of Pediatric IgAN and IgAVN, 60 children (24 IgAN and 36 IgAVN) were included in the study. The control group consisted of 20 healthy children. Proteinuria, haematuria, serum creatinine as well as IgA and C3 levels were measured and glomerular filtration rate (GFR) was calculated at onset and at the end of the follow-up. Kidney biopsy findings were evaluated using the Oxford classification. Serum Gd-IgA1 and serum and urine TNFR1 levels were measured at the end of follow-up. RESULTS: Serum Gd-IgA1 level was significantly higher in IgAN and IgAVN patients in comparison to the control group. Urine TNFR1 was significantly higher in IgAN than in IgAVN and the control group. We did not observe any differences in sTNFR1 level between IgAN, IgAVN and control groups. We found a positive correlation between Gd-IgA1 and creatinine (r = 0.34), and negative between Gd-IgA1 and GFR (r = -0.35) at the end of follow-up. We observed a negative correlation between uTNFR1/creatinine log and albumin level and protein/creatinine ratio. We did not find any correlations between Gd-IgA1 and TNFR1. CONCLUSIONS: The prognostic value of sGd-IgA1 in children with IgAN and IgAVN has been confirmed. TNFR1 is not associated with Gd-IgA1 and is not a useful prognostic marker in children with IgAN/IgAVN and normal kidney function.

Acute tubulointerstitial nephritis following aciclovir treatment for chickenpox in children with nephrotic syndrome - a report of two cases.

Tubulointerstitial nephritis (TIN) is an inflammatory process primarily involving the renal interstitium and is the cause of acute kidney injury (AKI) in 3-7% of cases confirmed by renal biopsy in children. Aciclovir may have a nephrotoxic effect by crystallization in renal tubules or by inducing an immunologic process that leads to development of TIN. We report 2 male patients, aged 10 and 8 years, with nephrotic syndrome (NS), in whom disease relapse was triggered by varicella zoster infection. The patients received intravenous aciclovir which resulted in AKI due to acute TIN with the glomerular filtration rate 19.5 and 24.9 ml/min/1.73 m2, respectively. The diagnosis was confirmed by kidney biopsy in one of these patients. Initiation of glucocorticosteroids and withdrawal of aciclovir resulted in resolution of proteinuria and symptoms of AKI. In children with active NS treated with intravenous aciclovir, a possibility of AKI due to TIN should be taken into account.

Cutaneous and systemic granulomatosis in ataxia-telangiectasia: a clinico-pathological study.

INTRODUCTION: The development of granulomas is a well-recognized manifestation of immunodeficiency in ataxia-telangiectasia (A-T), resulting from lymphocyte developmental abnormalities, impaired immunosurveillance, and inappropriate innate immune response-driven inflammation. AIM: To better understand pathological and immunological phenomena involved in development of cutaneous and visceral granulomatosis observable in patients with ataxia-telangiectasia. MATERIAL AND METHODS: We retrospectively reviewed medical records of eight A-T children, aged from 2 to 13 years, with regard to clinical, immunological and histopathological features of cutaneous and visceral granulomatosis. RESULTS: In four out of eight A-T patients studied, cutaneous granulomas clinically presented as skin nodules and ulcerated erythematous plaques disseminated on the face, and on trauma-prone areas of upper and lower extremities. Visceral granulomatosis had a severe clinical course and involved the lungs, the spleen, the liver and the larynx. Histologically, cutaneous and laryngeal granulomas showed extensive cellular infiltrations containing T lymphocytes with predominating CD8+ phenotype and with CD68+ histiocytes. The immunological profile with the hyper-IgM phenotype, markedly reduced numbers of B and naive CD4+ and CD8+ T cells with predominating IgM-only memory B cells and skewed repertoire of a T cell receptor was observable in patients with skin and visceral granulomatosis. CONCLUSIONS: In the setting of combined immunodeficiency in A-T, cutaneous and systemic granulomatosis reflects a granulomatous reaction pattern, as a result of inappropriate immune regulation.

[Influence of intensity, localization and type of deposits in renal biopsy for disease symptoms and follow up in children with IgA nephropathy]. / Wplyw nasilenia, lokalizacji i rodzaju zlogów w biopsji nerki na objawy kliniczne i rokowanie u dzieci z nefropatia IgA.

IgA nephropathy is the most common glomerulonephritis in the world. For diagnosis kidney biopsy is necessary. AIM: The aim of the study was assessment the significance of IgA, C3 and IgG deposits intensity and location in kidney childhood IgA nephropathy (IgAN) for the symptoms of the disease and the follow up. MATERIALS AND METHODS: Study population consisted of 81 children, average 11,45±3,99 years. IgAN was recognized based on renal biopsy, performed 1,2±1,84, median 0,5 years after the onset. We used Oxford classification (OC) to assess the severity of histopatological lesions. In renal biopsy IgA and C3 deposits were found in immunofluorescence in mesangium or in vessels of glomeruli or both, and intensity was defined 0 to +4. We analyzed: proteinuria (mg/kg/day), hematuria, creatinine, GFR (according to Schwartz formula) two times, at the onset of the disease (OOD) and at the follow up (FU). Patients were treated with: ACEI/ARB or steroids alone or with imunossupresion drugs: azathioprine (AZA), cyclophosphamide (CYC), cyclosporine A (CsA), mycopnenolate mophetil (MMF). The follow up was 3,31±2,88 years. We divided the patients into two groups, depending on the intensity of IgA deposits: G1 n=29 (+1/+2), G2 n=52 (+3/+4); depending on the localizations of these deposits, we analyzed 3 groups: A n= 39 (mesangium), B n= 15 (glomeruli vessels), C n=27 (both) and depending on the kind of deposits we analyzed 4 groups: gr. a - n=30 (only IgA), gr. b - n=37 (IgA+C3), gr. c - n=5 (IgA+IgG) gr. d - n= 9 (IgA+IgG+C3). RESULTS: At OOD and FU we not found any differences in G1 vs G2 for: age, proteinuria, GFR and OC in renal biopsy; at FU GFR<90 ml/ min/1,73 m2 FU was observed more frequently in G2 vs G1 (p=0,02). The differences in groups A,B,C and groups a,b,c,d were not found. CONCLUSIONS: Poor prognosis in childhood IgAN may also depend on the intensity of the deposits, irrespective of their location.

Serum GDIgA1 levels in children with IgA nephropathy and Henoch-Schönlein nephritis.

INTRODUCTION: GDIgA1 (galactose deficient IgA1) plays a significant role in the pathogenesis of IgA nephropathy (IgAN) and Henoch-Schönlein nephritis (HSN). AIM OF THE STUDY: The aim of this study was to assess the relevance of serum GDIgA1 level as a prognostic marker in children with IgAN and HSN. MATERIAL AND METHODS: 41 children were included to the study group (15 IgAN, 26 HSN) and 22 to the control group. The following parameters were evaluated at baseline and endpoint: proteinuria, erythrocyturia, serum creatinine, serum IgA, GFR. A kidney biopsy was performed in all patients and evaluated according to the Oxford Classification (1 - present, 0 - absent: M - mesangial hypercellularity; E- endocapillary hypercellularity; S - segmental sclerosis/adhesion; T - tubular atrophy/interstitial fibrosis), and was calculated as the total score (sum of M, E, S, T). At the end of follow-up, the serum GDIgA1 concentration was measured. RESULTS: The serum GDIgA1 concentration in patients with IgAN and HSN was significantly higher than in the control group. No significant differences in mean proteinuria, erythrocyturia, GFR, MEST score, or GDIgA1 in serum, as well as the duration of follow-up between IgAN and HSN were observed. Baseline serum IgA concentration and time to kidney biopsy were significantly higher in children with IgAN than in children with HSN. We observed a positive correlation between GDIgA1 and IgA levels (r = 0.53), and GDIgA1 and serum creatinine levels (r = 0.5), as well as negative correlation between GDIgA1 and GFR (r = -0.37). CONCLUSIONS: Serum GDIgA1 level may have a prognostic value in children with IgAN and HSN; however, to fully elucidate its clinical potential further studies performed in larger patient cohorts are required.

Risk factors for progression in children and young adults with IgA nephropathy: an analysis of 261 cases from the VALIGA European cohort.

BACKGROUND: There is a need for early identification of children with immunoglobulin A nephropathy (IgAN) at risk of progression of kidney disease. METHODS: Data on 261 young patients [age <23 years; mean follow-up of 4.9 (range 2.5-8.1) years] enrolled in VALIGA, a study designed to validate the Oxford Classification of IgAN, were assessed. Renal biopsies were scored for the presence of mesangial hypercellularity (M1), endocapillary hypercellularity (E1), segmental glomerulosclerosis (S1), tubular atrophy/interstitial fibrosis (T1-2) (MEST score) and crescents (C1). Progression was assessed as end stage renal disease and/or a 50 % loss of estimated glomerular filtration rate (eGFR) (combined endpoint) as well as the rate of renal function decline (slope of eGFR). Cox regression and tree classification binary models were used and compared. RESULTS: In this cohort of 261 subjects aged <23 years, Cox analysis validated the MEST M, S and T scores for predicting survival to the combined endpoint but failed to prove that these scores had predictive value in the sub-group of 174 children aged <18 years. The regression tree classification indicated that patients with M1 were at risk of developing higher time-averaged proteinuria (p < 0.0001) and the combined endpoint (p < 0.001). An initial proteinuria of ≥0.4 g/day/1.73 m2 and an eGFR of <90 ml/min/1.73 m2 were determined to be risk factors in subjects with M0. Children aged <16 years with M0 and well-preserved eGFR (>90 ml/min/1.73 m2) at presentation had a significantly high probability of proteinuria remission during follow-up and a higher remission rate following treatment with corticosteroid and/or immunosuppressive therapy. CONCLUSION: This new statistical approach has identified clinical and histological risk factors associated with outcome in children and young adults with IgAN.

Usefulness of urinary collagen IV excretion for predicting the severity of Henoch-Schönlein nephropathy children.

THE AIM OF THE STUDY: The aim of the study was to evaluate the usefulness of urinary collagen IV (Col IV) excretion for predicting the severity of autoimmune renal inflammation in children with HSN (Henoch-Schönlein nephritis). MATERIAL AND METHODS: We studied 26 children, in whom HSN was diagnosed based on kidney biopsy. In all patients, urinalysis was performed and 24-hour urinary protein excretion was measured at the onset of the disease. All kidney biopsies were also scored using the Oxford classification: M - mesangial hypercellularity score (M0 absent, M1 present); E - presence of endocapillary proliferation (E0 absent, E1 present), S - segmental glomerulosclerosis/adhesion (S0 absent, S1 present), T - tubular atrophy/interstitial fibrosis (T0 ≤ 25%, T1 26-50%, T2 > 50%). The MEST score was calculated as the sum of M + E + S + T. RESULTS: Urinary Col IV level was significantly higher in the study group than in control group. Urinary Col IV level was insignificantly higher in group A (nephrotic proteinuria) compared to the B (non-nephrotic proteinuria) and C (without proteinuria).We found no significant differences in the age at the disease onset, severity of proteinuria, and Col IV between groups 1 (S0, T0) and 2.(S1,T1/T2). The MEST score was significantly higher in group 2 than group 1. CONCLUSIONS: Urinary Col IV excretion in children with HSN may be related to the lesions severity by the Oxford classification but seems to be associated with the mean value (the MEST score). In younger children, a more aggressive disease course is observed, and thus earlier and more aggressive treatment should be considered in this group.

Treatment Outcomes in Children with Henoch-Schönlein Nephritis.

The aim of the present study was to quantify the effects of treatment of children with Henoch-Schönlein nephritis (HSN) evaluated on the basis of kidney biopsy findings. Data were analyzed from 32 patients with HSN (mean age 9.3 ± 3.5 years, 19 with nephrotic syndrome/nephrotic proteinuria NS/NP, 13 with nephritic syndrome NphS), in whom the diagnosis was confirmed by kidney biopsy. Patients received immunosuppressive treatment (azathioprine or cyclophosphamide) and/or steroids and renoprotection according to a defined protocol. Patients were referred to a specific treatment protocol selected on the basis of clinical symptoms of nephropathy (NS/NP or NphS) and histopathological grade according to the WHO classification. Grade I-II changes were defined as mild HSN, and grade III-V WHO as severe HSN. The follow-up kidney biopsy was performed upon obtaining parental consent in 17 children. Following treatment, proteinuria resolved in 78 % children with mild HSN and 87 % children with severe HSN. In kidney biopsy, histological improvement was seen in 59 % children and no worsening in 35 %. We conclude that a flexible treatment protocol related to clinical symptoms and histological staging may contribute to a reduction of proteinuria and a delay in disease progression in children with HSN.

Lupus nephritis in children - 10 years' experience.

Systemic lupus erythematosus (SLE) in children is usually more severe than it is in adults and there is a higher incidence of renal involvement. We described 18 children (16 girls, 2 boys) with lupus nephritis (LN), whose average age was 14.4 ±1.81 years. Disease activity was assessed according to SLEDAI (SLE Disease Activity Index). Renal biopsy was classified according to the INS/RPS (International Society of Nephrology/Renal Pathology Society). The patients were treated with steroids (100%) and pulses of cyclophosphamide (88.9%) or mycophenolate mofetil (11.1%), next azathioprine or mycophenolate mofetil with prednisone in reduced doses. In children with renal/multi-organ insufficiency and/or septicaemia, renal replacement therapy (27.8%), and plasmapheresis (22.2%) were used in the initial treatment. The SLEDAI initial activity was high in 44.4% and moderate in 55.6% of children. LN manifested as: nephrotic syndrome (83.3%), microhaematuria (100%), leukocyturia (60%), hypertension (72.2%), and acute renal injury (83.3%); mean GFR was 54.55 ±33.09 ml/min/1.73 m2. In the renal biopsy, class IV LN according to INS/RPS was mainly diagnosed (82%). At the end of follow-up, mean observation time 32.1±23.36 months: mean GFR was 90.87 ±12.13 ml/min/1.73 m2, proteinuria disappeared in 66.7% and decreased in 33.3% of children to the average of 1.7 g/day (range: 0.5-4.0 g/day), hypertension was observed in 83.4% of children. Intensive immunosuppressive treatment with pulses of cyclophosphamide in early stage of LN in children is very effective.

Relationship between serum IgA/C3 ratio and severity of histological lesions using the Oxford classification in children with IgA nephropathy.

BACKGROUND: The aim of this study was to evaluate the usefulness of serum immunoglobulin A/complement factor 3 (IgA/C3) ratio for predicting histological severity of kidney lesions in children with IgA nephropathy (IgAN) based on World Health Organization (WHO) and the Oxford classification (OC). METHODS: We studied 89 children with IgAN with a mean age of 11.38 ± 4.1 years (range 2-18 years). Based on available medical records, we retrospectively evaluated clinical data, IgA/C3 ratio, and kidney biopsy findings using the five-grade WHO classification and the OC The mesangial hypercellularity (M), endocapillary hypercellularity (E), segmental sclerosis (S), tubular atrophy/interstitial fibrosis (T) (MEST) score (absent = 0, present = 1) calculated as the sum of M+E+S+T ranging from 0 to 4. RESULTS: Mean IgA/C3 ratio values were significantly higher (P < 0.05) in patients with M1, S1, and T1 compared with M0, S0, and T0, respectively (P < 0.05); there were no differences in the WHO classification. We found a significant positive correlation between the IgA/C3 ratio and proteinuria (r = 0.24) and determined optimal cutoff values of the IgA/C3 ratio, with a corresponding confidence interval for specific MEST scores. CONCLUSIONS: The IgA/C3 ratio in children with IgAN may be a useful marker of the severity of lesions found in kidney biopsy as evaluated using the OC.

Evaluation of calretinin immunohistochemistry as an additional tool in confirming the diagnosis of Hirschsprung disease.

Hirschsprung disease (HD) is a congenital malformation defined as the absence of myenteric and submucosal ganglion cells (GCs) in the distal rectum and variable length of the contiguous bowel. The aim of this study was to assess the utility of calretinin immunochemistry in comparison with that of standard histology complemented with acetylcholinesterase (AChE) histochemistry routinely employed at our institution to evaluate rectal biopsies carried out for suspicion of HD. Twenty-one rectal biopsies were reviewed, including 14 from patients with suspected HD, 6 from infants with necrotizing enterocolitis (NEC), and 1 from a patient diagnosed with spontaneous intestinal perforation (SIP). Sections stained with hematoxylin-eosin (HE) revealed absence of ganglion cells in 13 cases which included 11 patients with HD and 2 patients with NEC. Among 13 cases of aganglionosis the AChE reaction pattern was consistent with HD in 2 patients. Calretinin positivity was observed in all rectal biopsies showing the presence of GC, and the staining was consistently absent in all cases of aganglionosis. In 6 rectal biopsies in which abnormal acetylcholinesterase (AChE) staining was not seen, loss of calretinin immunoreactivity helped establish the diagnosis of HD.

ALK-positive anaplastic large cell lymphoma limited to the skin: clinical, histopathological and molecular analysis of 6 pediatric cases. A report from the ALCL99 study.

Anaplastic large cell lymphomas are peripheral T-cell lymphomas that are characterized by a proliferation of large anaplastic blasts expressing CD30. In children, systemic anaplastic large cell lymphomas often present at advanced clinical stage and harbor translocations involving the anaplastic lymphoma kinase (ALK) gene leading to the expression of chimeric anaplastic lymphoma kinase (ALK)-fusion proteins. Primary cutaneous anaplastic large cell lymphoma is regarded as an ALK-negative variant confined to the skin and is part of the spectrum of primary cutaneous CD30-positive T-cell lymphoproliferative disorders. Thirty-three of 487 pediatric patients registered within the Anaplastic Large Cell Lymphoma-99 trial (1999 to 2006) presented with a skin limited CD30-positive lympho-proliferative disorder. In 23 of the 33 patients, material for international histopathological review was available, and the cases were studied for histopathological, immunophenotypical and clinical features as well as for breaks within the ALK gene. Five of 23 cases and one additional case (identified after closure of the trial) expressed ALK-protein. Complete staging excluded any other organ involvement in all children. Expression of ALK proteins was demonstrated by immunohistochemistry in all cases and the presence of breaks of the ALK gene was genetically confirmed in 5 evaluable cases. The histopathological and clinical picture of these skin-restricted ALK-positive lymphomas was indistinguishable from that of cutaneous anaplastic large cell lymphoma. Five children presented with a single skin lesion that was completely resected in 4 and incompletely resected in one. Three of these patients received no further therapy, 2 additional local radiotherapy, and one chemotherapy. All children remain in complete remission with a median follow up of seven years (range 1-8 years). We present 6 pediatric cases of ALK-positive primary cutaneous anaplastic large cell lymphomas. After thorough exclusion of systemic involvement, therapy confined to local measures seems to be sufficient to induce cure.

[Congenital epulis of a newborn twin--a case report]. / Nadziaslak u noworodka z ciazy blizniaczej--opis przypadku.

We present a case of a female neonate, born at 36 weeks of gestation from a monochorionic, diamniotic spontaneous twin pregnancy with congenital epulis, 2.5 cm in size, protruding from the oral cavity. Histopathology revealed a typical granular cell lesion. The other twin, also female, was prenatally diagnosed with congenital heart defect: pulmonary stenosis. The tumor was typically located in the maxillary alveolar ridge and unidirectional. The child underwent a successful surgery on the first day after birth. The course of the procedure and recovery was uneventful.

Case report: Cellular therapy for hydroa vacciniforme-like lymphoproliferative disorder in pediatric common variable immunodeficiency with chronic active Epstein-Barr virus infection.

Hydroa vacciniforme-like lymphoproliferative disorder (HV-LPD) is a cutaneous form of chronic active Epstein-Barrvirus (EBV) infection, which can develop into the extremely rare systemic lymphoma. Patients with Inborn errors of immunity (IEI), such as common variable immunodeficiency (CVID), are at higher risk of developing a severe course of infections especially viral and malignancies than the general population. The aim of the study was to present complex diagnostic and therapeutic management of HV-LPD. The clinical diagnosis was confirmed at the histological and molecular level with next generation sequencing. HV-LPD was diagnosed in a patient with CVID and chronic active Epstein-Barr virus (CAEBV) infection. The patient was refractory to CHOP chemotherapy and immunosuppressive treatment in combination with antiviral drugs (prednisone, bortezomib, gancyclovir). The third-party donor EBV-specific cytotoxic T cells (EBV-CTL, tabelecleucel) were used, which stabilised the disease course. Finally, matched unrelated donor hematopoietic cell transplantation (MUD-HCT) was performed followed by another cycle of EBV-CTL.

Case Report: Autoimmune Lymphoproliferative Syndrome vs. Chronic Active Epstein-Barr Virus Infection in Children: A Diagnostic Challenge.

Autoimmune lymphoproliferative syndrome (ALPS) is a disorder characterized by a disruption of the lymphocyte apoptosis pathway, self-tolerance, and immune system homeostasis. Defects in genes within the first apoptosis signal (FAS)-mediated pathway cause an expansion of autoreactive double-negative T cells leading to non-malignant lymphoproliferation, autoimmune disorders, and an increased risk of lymphoma. The aim of the study was to show the diagnostic dilemmas and difficulties in the process of recognizing ALPS in the light of chronic active Epstein-Barr virus (CAEBV) infection. Clinical, immunological, flow cytometric, biomarkers, and molecular genetic approaches of a pediatric patient diagnosed with FAS-ALPS and CAEBV are presented. With the ever-expanding spectrum of molecular pathways associated with autoimmune lymphoproliferative disorders, multiple genetic defects of FAS-mediated apoptosis, primary immunodeficiencies with immune dysregulation, malignant and autoimmune disorders, and infections are included in the differential diagnosis. Further studies are needed to address the issue of the inflammatory and neoplastic role of CAEBV as a triggering and disease-modifying factor in ALPS.

IgA Vasculitis Complicated by Both CMV Reactivation and Tuberculosis.

Immunoglobulin A (IgA) vasculitis is the most common systemic vasculitis in the pediatric population. We present the case of a patient with IgA vasculitis with nephritis who developed cytomegalovirus (CMV) infection followed by Mycobacterium tuberculosis infection. In the literature, there are a few cases of IgA nephropathy accompanied by reactivation of CMV or tuberculosis. To the best of our knowledge, this is the first reported case of IgA vasculitis complicated by both CMV reactivation and tuberculosis. It is important to detect infections in patients with IgA vasculitis because they can induce and exacerbate the symptoms of the disease. Effective antimicrobial treatment facilitates the management of proteinuria and slows down the decline of renal function. Immunosuppressive therapy is a risk factor for reactivation of latent infections and makes patients more susceptible to its generalized and complicated course. This can be prevented by actively screening for hidden sites of infection.

IgA vasculitis nephritis clinical course and kidney biopsy - national study in children.

The aim of the study was to investigate the relationship between the severity of typical clinical symptoms, severity of histopathological lesions in kidney biopsies in IgA vasculitis nephritis (IgAVN) and to propose indications for kidney biopsy in children. MATERIAL AND METHODS: This retrospective study enrolled 106 patients, included in the IgAVN registry of Polish children, diagnosed by kidney biopsy. Renal and extrarenal symptoms at onset of the disease were analyzed. Biopsy results were assessed using Oxford classifications (MEST-C). The patients were divided into 3 groups depending on the severity of proteinuria: A-nephrotic proteinuria with hematuria; B-non-nephrotic proteinuria with hematuria; C-isolated hematuria. RESULTS: The first symptoms of nephropathy were observed at the 0.7 (1-128.4) months from the onset of extrarenal symptoms. Kidney biopsy was performed on 39 (6-782) days after the onset of nephropathy symptoms. MEST-C score 4 or 5 was significantly more frequent in children from group A than in groups B and C. Significantly higher mean MEST-C score was found in patients with abdominal symptoms than without. In group A: S0 and T0 we found in significantly shorter time to kidney biopsy than in S1, T1-2 p < 0.05) and in group B the significantly shorter time in T0 compare to T1-2 p < 0.05). The ROC analysis shows that S1 changes appear in kidney biopsies in group A with cut off 21 days (AUC 0,702, p = 0.004, sensitivity 0.895 specificity 0.444) T1-2 changes after 35 days (AUC 0.685, p = 0.022, sensitivity 0.750, specificity 0.615), and in goupn B T1-2 cut off is 74 days (AUC 0,738, p = 0.002, sensitivity 0.667, specificity 0.833). CONCLUSIONS: In childhood IgAVN, the severity of changes in the urine is clearly reflected in the result of a kidney biopsy. The biopsy should be performed in patients with nephrotic proteinuria no later than 3 weeks after the onset of this symptom in order to promptly apply appropriate treatment and prevent disease progression. Accompanying abdominal symptoms predispose to higher MESTC score.