Incidence and risk factors of opportunistic infections after autologous stem cell transplantation: a nationwide, population-based cohort study in Korea

Several guidelines classify autologous stem cell transplantation (ASCT) as a low to intermediate risk group for infection. In a nationwide population-based study, using the Korean Health Insurance Review and Assessment Service database, patients with lymphoma and multiple myeloma (MM) who underwent ASCT from 2002 to 2016 were retrospectively analyzed. Cumulative incidence rates (CIRs) and risk factors of opportunistic infections were investigated. CIRs of fungal, Varicella zoster virus (VZV), cytomegalovirus (CMV), and Pneumocystis jirovecii infections in lymphoma were 7.9%, 16.0%, 7.4%, and 5.1%, respectively, and CIRs in MM were 6.3%, 19.1%, 4.2%, and 5.6%, respectively. Fungal infection was significantly higher in patients with previous infection (Hazard ratio (HR) 2.003, p = 0.005) in lymphoma. Incidence of CMV infection was significantly higher in patients with prior CMV infection: HR 4.920, p < 0.001 (lymphoma); HR 3.022, p = 0.030 (MM). VZV infection was significantly lower in patients receiving prophylaxis: HR 0.082, p < 0.001 (lymphoma); HR 0.096, p < 0.001 (MM). For P. jirovecii infection, busulfex and melphalan conditioning (HR 1.875, p = 0.032) and previous P. jirovecii infection (HR 4.810, p < 0.001) had a higher incidence in MM. Patients who underwent ASCT should receive VZV prophylaxis and prophylaxis for fungal and P. jirovecii may be considered in patients with previous same infection.

Nonfatal injuries in Korean children and adolescents, 2007-2018

BACKGROUND

Injury is the leading cause of death or disability in children and adolescents. Rates of deaths from injuries have recently declined, but studies of the occurrence of nonfatal injuries are lacking.

PURPOSE

This study aimed to investigate nonfatal injuries in children and adolescents younger than 20 years based on data from the Korean National Health and Nutrition Survey, 2007-2018.

METHODS

A questionnaire survey was conducted to determine whether children and adolescents had experienced an injury requiring a hospital visit in the previous year. We investigated each injury's risk factors and characteristics.

RESULTS

Of a total of 21,598 children and adolescents, 1,748 (weighted percentage, 8.1%) experienced one or more injuries in the previous year. There was no yearly difference in the proportion of injuries experienced. Among the male subjects, 10.0% had an injury experience; among the female participants, 6.1% had an injury experience (P<0.001). The highest rate was 9.0% in children aged 1-4 years. In multivariate logistic regression analysis, male sex; having an urban residence; having restricted activity due to visual, hearing, or developmental impairment; and attention deficit/hyperactivity disorder were significant risk factors for injury experience. The characteristics of up to 3 injuries per patient were investigated, and 1,951 injuries were analyzed. Falls and slips accounted for 34.9%, collisions for 34.1%, and motor vehicle accidents for 11.3% of the total injuries. Ninety-six percent of injuries were unintentional, 20% caused school absences, and 10% required hospitalization.

CONCLUSION

Among Korean children and adolescents, 8.1% experienced injuries at least once a year with no significant differences in incidence over the past 12 years. Greater attention and effort to prevent injuries are needed.

Influence of creatinine levels on survival in patients with veno-occlusive disease treated with defibrotide

BACKGROUND/AIMS

Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is one of the most fatal complications of hematopoietic cell transplantation (HCT), and defibrotide is the only curative drug. We conducted this study to confirm the survival rate of VOD/SOS patients diagnosed in Korea and assess the efficacy of defibrotide.

METHODS

Patients diagnosed with VOD/SOS after allogenic HCT between 2003 and 2020 were enrolled. We investigated day +100 survival rates and associated risk factors in patients who satisfied the modified Seattle criteria within 50 days of HCT.

RESULTS

A total of 110 patients satisfied the modified Seattle criteria, of which 65.5% satisfied the Baltimore criteria. Thirty-seven patients were treated with defibrotide. The day +100 survival rate of the 110 patients was 65.3%. The survival rates in patients who did not meet the Baltimore criteria and in those who did were 86.8% and 53.7%, respectively (p = 0.001). The day +100 survival rate of patients treated with defibrotide was 50.5%. Among the patients receiving defibrotide, those whose creatinine levels were more than 1.2 times the baseline had a significantly lower survival rate at 26.7% (p = 0.014). On multivariate regression analysis, the hazard ratio of satisfaction of the Baltimore criteria was 4.54 (95% confidence interval [CI], 1.69 to 12.21; p = 0.003). In patients treated with defibrotide, the hazard ratio was 8.70 (95% CI, 2.26 to 33.45; p = 0.002), when creatinine was more than 1.2 times the baseline on administration.

CONCLUSION

The day +100 survival rate was significantly lower when the Baltimore criteria were satisfied, and when there was an increase in creatinine at the time of defibrotide administration.

Early transplantation-related mortality after allogeneic hematopoietic cell transplantation in patients with acute leukemia

Background

Transplantation-related mortality (TRM) is a major obstacle in allogeneic hematopoietic cell transplantation (allo-HCT). Approximately 60–80% of TRM occurs early, within 100 days of transplantation.

Methods

This was a nationwide population cohort study involving 5395 patients with acute leukemia who underwent allo-HCT between 2003 and 2015. Patient data were collected from the Korean National Health Insurance Service database. We investigated the cumulative incidence rates (CIRs) of early TRM at 50 and 100 days.

Results

The CIRs of early TRM at 50 and 100 days were 2.9 and 8.3%, respectively. There was no decrease in the CIRs of early TRM over time. The early mortality was significantly higher in patients with more than 9 months between the diagnosis and transplantation (CIRs of TRM at 50, 100 days; 6.0, 13.2%), previous transplantations (CIRs of TRM at 50, 100 days; 9.4, 17.2%), and cord blood transplantation (CIRs of TRM at 50, 100 days; 6.1, 8.3%). The early TRM was significantly lower in patients who received iron chelation before transplantation (CIRs of TRM at 50, 100 days; 0.3, 1.8%).

Conclusions

In conclusion, the overall CIR of early TRM was less than 10%. The predictable factors for early TRM included age, time from diagnosis to transplantation, the number of prior transplantations, the graft source, and previous iron chelation therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07897-3.

Changes in the prevalence of anemia in Korean adolescents, 1998-2018

BACKGROUND

Anemia is an important health problem affecting approximately 25% of the global population. Although its prevalence is decreasing worldwide, few studies have examined the prevalence of anemia in Korean adolescents.

PURPOSE

This study aimed to determine the prevalence of anemia in Korean adolescents over the past 21 years using data from the Korea National Health and Nutrition Examination Survey.

METHODS

We investigated the prevalence of anemia in adolescents aged 10-18 years for the period 1998-2018 according to sex, age, residential area, and household income. The effects of menarche age and menstruation were examined in female adolescents for the period 2001-2018.

RESULTS

Among the total 11,782 participants, the weighted prevalence of anemia was 4.0%. The prevalence of anemia in male participants significantly decreased (from 3.0% to 0.5%, P<0.001), whereas that in female participants did not change significantly over time (from 7.9% to 8.5%, P=0.054). The average age at menarche was 12.4±0.0 years; the prevalence of anemia in females increased from age 13 years onward. Multivariate analysis revealed that anemia was more common in female than male participants (odds ratio [OR], 9.88; 95% confidence interval [CI], 7.19-13.57; P<0.001). In female adolescents, the prevalence of anemia increased with age (OR, 1.26; 95% CI, 1.15-1.38, P<0.001) and was 3.6 times higher after than before menarche (OR, 3.65; 95% CI, 2.21-6.05, P<0.001).

CONCLUSION

Over the 21-year study period, the prevalence of anemia decreased among male adolescents but did not change in female adolescents. In female adolescents, age and menarche were identified as significant risk factors that require continued attention.

Epidemiological Study of Hereditary Hemolytic Anemia in the Korean Pediatric Population during 1997-2016: a Nationwide Retrospective Cohort Study

BACKGROUND

Hereditary hemolytic anemia (HHA) is a rare disease characterized by premature red blood cell (RBC) destruction due to intrinsic RBC defects. The RBC Disorder Working Party of the Korean Society of Hematology established and updated the standard operating procedure for making an accurate diagnosis of HHA since 2007. The aim of this study was to investigate a nationwide epidemiology of Korean HHA.

METHODS

We collected the data of a newly diagnosed pediatric HHA cohort (2007-2016) and compared this cohort's characteristics with those of a previously surveyed pediatric HHA cohort (1997-2006) in Korea. Each participant's information was retrospectively collected by a questionnaire survey.

RESULTS

A total of 369 children with HHA from 38 hospitals distributed in 16 of 17 districts of Korea were investigated. RBC membranopathies, hemoglobinopathies, RBC enzymopathies, and unknown etiologies accounted for 263 (71.3%), 59 (16.0%), 23 (6.2%), and 24 (6.5%) of the cases, respectively. Compared to the cohort from the previous decade, the proportions of hemoglobinopathies and RBC enzymopathies significantly increased (P < 0.001 and P = 0.008, respectively). Twenty-three of the 59 hemoglobinopathy patients had immigrant mothers, mostly from South-East Asia.

CONCLUSION

In Korea, thalassemia traits have increased over the past 10 years, reflecting both increased awareness of this disease and increased international marriages. The enhanced recognition of RBC enzymopathies is due to advances in diagnostic technique; however, 6.5% of HHA patients still do not have a clear diagnosis. It is necessary to improve accessibility of diagnosing HHA.

The risk factors associated with treatment-related mortality in 16,073 kidney transplantation-A nationwide cohort study

Mortality at an early stage after kidney transplantation is a catastrophic event. Treatment-related mortality (TRM) within 1 or 3 months after kidney transplantation has been seldom reported. We designed a retrospective observational cohort study using a national population-based database, which included information about all kidney recipients between 2003 and 2016. A total of 16,073 patients who underwent kidney transplantation were included. The mortality rates 1 month (early TRM) and 3 months (TRM) after transplantation were 0.5% (n = 74) and 1.0% (n = 160), respectively. Based on a multivariate analysis, older age (hazard ratio [HR] = 1.06; P < 0.001), coronary artery disease (HR = 3.02; P = 0.002), and hemodialysis compared with pre-emptive kidney transplantation (HR = 2.53; P = 0.046) were the risk factors for early TRM. Older age (HR = 1.07; P < 0.001), coronary artery disease (HR = 2.88; P < 0.001), and hemodialysis (HR = 2.35; P = 0.004) were the common independent risk factors for TRM. In contrast, cardiac arrhythmia (HR = 1.98; P = 0.027) was associated only with early TRM, and fungal infection (HR = 2.61; P < 0.001), and epoch of transplantation (HR = 0.34; P < 0.001) were the factors associated with only TRM. The identified risk factors should be considered in patient counselling, selection, and management to prevent TRM.

Incidence, prevalence, mortality, and causes of death in Waldenström macroglobulinemia: a nationwide, population-based cohort study

BACKGROUND

The epidemiological features of Waldenström macroglobulinemia (WM) have seldom been investigated at a national level, particularly in East Asia. The goal of our study is to present the incidence, prevalence, mortality, survival with competing risks, and causes of death of patients with WM.

METHODS

We used a national population-based database, operated by the Health Insurance Review and Assessment Service of the Korean government. This data includes information on all WM patients diagnosed according to uniform criteria, between 2003 and 2016.

RESULTS

The total number of patients newly diagnosed with WM during the study period was 427, with a male-to-female ratio of 3.2:1. The incidence increased from 0.03 to 0.10 per 105 between 2003 and 2016, and the prevalence was 0.42 per 105 in 2016. A total of 217 patients with WM died during the study period (standardized mortality ratio = 7.57), and the overall survival (OS) of WM patients was 47.5%. On multivariate analysis, older age was associated with worse OS (P <  0.0001). WM was the most common cause of death (n = 102, 48.6%), followed by other malignant neoplasms (n = 82, 39.0%).

CONCLUSIONS

The national incidence of WM in Korea, a racially homogeneous country in Asia, was lower than that in previous reports from other countries, reflecting ethnic disparities. However, the incidence increased, and mortality was the highest ever reported. The main cause of death was WM in itself. This study reflects the need for greater awareness of WM, particularly in Asian countries.

Increased Prevalence of Thalassemia in Young People in Korea: Impact of Increasing Immigration

Background

Thalassemia is highly prevalent in Southeast Asia but is rare in Korea; however, Southeast Asian immigrant population is recently rising in Korea. We investigated the prevalence of thalassemia in Korea in the context of increasing immigration.

Methods

This prospective, observational, multicenter study was conducted between September 2015 and August 2017. A total of 669 subjects <30 years living in Korea were grouped into the multiethnic (N=314) and Korean (N=355) groups. Hb electrophoresis and complete blood count (CBC) were performed. If low mean corpuscular volume with high red blood cell distribution width coefficient of variation or a high fetal Hb (HbF) or Hb alpha 2 (HbA₂) level was observed, genetic testing of the α- and β-globin genes was performed. In addition, the number of potential thalassemia carriers in Korea was estimated by multiplying the prevalence of thalassemia in a specific ethnicity by the number of immigrants of that ethnicity.

Results

Twenty-six multiethnic and 10 Korean subjects showed abnormal results for Hb electrophoresis and CBC. Eighteen multiethnic subjects and four Korean subjects were tested for α-globin and β-globin gene mutations. Within the multiethnic group, five subjects (1.5%) were α-thalassemia carriers, and six (1.9%) were β-thalassemia minor. The SEA deletion in HBA1 and HBA2, and c. 126_129delCTTT (p.Phe42Leufs*19) mutation of HBB were the dominant inherited mutations.

Conclusions

The prevalence of thalassemia in young people in Korea is increasing due to the increasing number of Southeast Asian immigrants.

Current use of safety restraint systems and front seats in Korean children based on the 2008-2015 Korea National Health and Nutrition Examination Survey

PURPOSE

The use of proper safety restraint systems by children is vital for the reduction of traffic accident-related injury and death. This study evaluated the rates of use of safety restraint systems and front seats by Korean children.

METHODS

Based on data from the National Health and Nutrition Examination Survey from 2008 to 2015, I investigated the frequencies of safety restraint systems and front seat use by children under six and 12 years of age, respectively.

RESULTS

The percentage of respondents who said they always use safety restraint systems increased from 17.7% in 2008 to 45.0% in 2015. The rate of children who did not use the front seats at all was 47.3 % in 2008 compared to 33.4% in 2015. Multivariate logistic regression analysis showed a decrease in safety-restraint-system use as age increased (odds ratio, 0.63; 95% confidence interval [CI], 0.51-0.77). The use rate of front-passenger seat belts by the mother is significantly correlated with the safety-restraint- system use rate by children (odds ratio, 2.14; 95% CI, 1.12-4.06).

CONCLUSION

Although the rate of safety-restraint-system use for children is increasing annually, it remains low. Additionally, the use rate of front passenger seats for children is high. To reduce the rates of injury and death of children from traffic accidents, it is necessary to educate on the appropriate use of safety restraint systems according to age and body size and to develop stronger regulations.

T-Cell Receptor Rearrangements Determined Using Fragment Analysis in Patients With T-Acute Lymphoblastic Leukemia

Background

Chromosomal abnormalities and common genetic rearrangements related to T-acute lymphoblastic leukemia (T-ALL) are not clear. We investigated T-cell receptor (TCR) rearrangement in Korean T-ALL patients by fragment analysis, examining frequency, association between clinicopathologic characteristics and TCR clonality, and feasibility for detecting minimal residual disease (MRD).

Methods

In 51 Korean patients diagnosed as having T-ALL, TCR rearrangement was analyzed using the IdentiClone TCR gene clonality assay (InVivoScribe Technologies, San Diego, CA, USA) from archived bone marrow specimens. Limit of detection (LOD) and clonal stability at relapse were evaluated. The association between clinical prognosis and TCR clonality was examind by age and immunophenotypic classification.

Results

Thirty-eight patients (74.5%) had 62 clonal products of TCRβ, TCRγ, and/or TCRδ rearrangements at diagnosis. Children with T-ALL (<12 years) showed a higher frequency of clonality (93.8%) than adolescents/adults (65.7%; ≥12 years). Patients with a mature immunophenotype (84.4%) showed a relatively higher frequency of clonality than those with the immature immunophenotype (57.9%). Survival and event-free survival were not influenced by immunophenotype or TCR clonality. The LOD was 1%. Clonal evolution at the relapse period was noted.

Conclusions

The overall detection rate of TCR clonality was 74.5%. Survival did not differ by TCR clonality or immunophenotype and age group. Fragment analysis of TCR rearrangement cannot be used to assess MRD due to low sensitivity. Further research on the relationship between prognosis and frequency of TCR rearrangements is needed, using more sensitive methods to detect clonality and monitor MRD.

Antibiotic resistance of &lt;italic&gt;Staphylococcus aureus&lt;/italic&gt; colonized in children with staphylococcal scalded skin syndrome

Objectives Systemic antibiotic therapy with semisynthetic penicillinase-resistant penicillin or vancomycin and clindamycin are recommended for the treatment of staphylococcal scalded skin syndrome (SSSS). This study assessed the rate of antibiotic resistance of Staphylococcus aureus isolated from the anterior nares or skin of children diagnosed with SSSS. Methods A retrospective review of the medical records of 25 patients with SSSS between July 2010 and October 2014 was conducted. The clinical characteristics of patients were collected and the antibiotic susceptibility of S. aureus were analyzed using automated systems. Results The median age of the patients was 22 months (range: 2-95). Ninety-two percent of patients were less than 5 years of age. Nasal swab samples of all patients and skin swab samples of 17 patients were cultured to isolate S. aureus . Twenty-one (84%) of 25 patients were colonized with methicillin-resistant S. aureus (MRSA). The results of swab samples of the other four patients were no growth or isolation of bacteria other than S. aureus . Among 20 strains isolated from the anterior nares, 1 strain (5%) was methicillin-susceptible S. aureus . All 15 strains isolated from the skin were MRSA. All 21 strains isolated from anterior nares or skin were found to be resistant to clindamycin upon evaluation using automated systems. Conclusions The rates of methicillin and clindamycin resistance in S. aureus colonized in children with SSSS were very high. Further studies evaluating proper antibiotic regimens and the effectiveness of systemic antibiotic therapy are needed.

Treatment outcome of pediatric acute lymphoblastic leukemia in Yeungnam region: Multicenter retrospective study of Study Alliance of Yeungnam Pediatric Hematology-Oncology (SAYPH)

OBJECTIVES

We aimed to evaluate treatment outcomes of pediatric acute lymphoblastic leukemia (ALL) subgroups by risk-stratification, in the Yeungnam region of Korea.

METHODS

We reviewed the courses of 409 newly diagnosed ALL patients from January 2004 to December 2013 in the Yeungnam region.

RESULTS

All patients were classified into three risk groups: standard risk (SR, n=212), high risk (HR, n=153) and very high risk (VHR, n=44). The mean follow-up time was 73.6 ± 39.4 months. The 7-year event-free survival (EFS) and overall survival (OS) rates were 78.7 ± 2.1% and 86.8 ± 1.8%, respectively. Significant 7-year EFS and OS rates for SR (84.0 ± 2.7%, 93.7 ± 1.8%), HR (76.5 ± 3.5%, 82.1 ± 3.3%), and VHR (60.6 ± 7.5%, 69.9 ± 7.5%) were observed (P<0.001), respectively. Relapse occurred in 52 patients, and the cumulative 7-year incidence of relapse differed according to risk groups (SR vs. HR vs. VHR=12.6% vs. 14.0% vs. 29.6%, P=0.003).For the 46 relapsed patients who were treated, the 3-year EFS and OS were 42.3 ± 8.3%and 46.4± 8.4%. Among the 44 VHR patients, EFS was not significantly different between the chemotherapy-treated patients and those received hematopoietic stem cell transplantation (P=0.533). The 7-year EFS of the hyperleukocytosis subgroup (24 cases, 14 under 10 years of age)showed a tendency for better prognosis than that of the other VHR subgroups (P=0.178).

CONCLUSION

Our results revealed improved outcomes in pediatric ALL patients with risk-stratified therapy. The hyperleukocytosis subgroup without any combined chromosomal abnormalities may respond favorably to chemotherapy alone after first complete remission.

Childhood acute lymphoblastic leukemia with hyperleukocytosis at presentation

Background

Hyperleukocytosis caused by acute lymphoblastic leukemia (ALL) is associated with early morbidity and mortality due to hyperviscosity arising from the excessive number of leukocytes.This study was designed to assess the incidence of hyperleukocytosis, survival outcomes, and adverse features among pediatric ALL patients with hyperleukocytosis.

Methods

Between January 2001 and December 2010, 104 children with previously untreated ALL were enrolled at the Pusan National University Hospital. All of them were initially stratified based on the National Cancer Institute (NCI) risk; 48 (46.2%) were diagnosed with high-risk ALL. The medical charts of these patients were retrospectively reviewed.

Results

Twenty (19.2%) of the 104 children with ALL had initial leukocyte counts of >100×10⁹/L, and 11 patients had a leukocyte count of >200×10⁹/L. Male gender, T-cell phenotype, and massive splenomegaly were positively associated with hyperleukocytosis. Common early complications during induction therapy included renal dysfunction, and central nervous system hemorrhage. The complete remission (CR) rate for the pediatric ALL patients with hyperleukocytosis (94.1%) was similar to the overall CR rate (95.6%). The estimated 3-year event free survival (EFS) and overall survival of ALL children with hyperleukocytosis were 75.0% and 81.2%, respectively. However, patients with initial leukocyte counts >200×10⁹/L had a lower EFS than those with initial leukocyte counts 100-200×10⁹/L (63.6% vs. 100%; P=0.046).

Conclusion

The outcome of pediatric ALL cases with an initial leukocyte count >200×10⁹/L was very poor, probably due to early toxicity-related death during induction therapy.

Clinical Characteristics of Pandemic Influenza A (H1N1) 2009 Pediatric Infection in Busan and Gyeongsangnam-do: One Institution

Background

This study investigated the clinical characteristics and risk factors of the severity of pandemic influenza A (H1N1) 2009 infection in pediatric patients in Busan and Gyeongsangnam-do.

Methods

Cases of influenza A (H1N1) 2009 in patients under the age of 18 years, confirmed by reverse transcription polymerase chain reaction, at Pusan National University Hospital and Pusan National University Yangsan Hospital from the last week of August 2009 through the last week of February 2010 were retrospectively analyzed.

Results

Of the 3,777 confirmed cases of influenza A (H1N1) 2009, 2,200 (58.2%) were male and 1,577 (41.8%) were female. The average age of the patients was 8.4±4.8 years. The total cases peaked during 44th to 46th week. Most of the patients were in the 5- to 9-year-old age group. Oseltamivir was administered to 2,959 (78.3%) of the patients. 221 patients (5.9%) were hospitalized, age an average of 6.7±4.5 years. The average duration of hospitalization was 7.4±5.6 days. One hundred cases (45.2%) had pneumonia. Risk factors for hospitalization included male gender, <2 years of age, and underlying disease. Children with asthma were at very high risk of hospitalization, over 20 times the non-asthmatic children (odds ratio [OR], 21.684; confidence interval [CI], 13.295~39.791). Likewise the children with neurologic deficits faced a 16 times higher risk (OR, 15.738; CI, 7.961~31.111). Ten of the patients (4.5%) were admitted to the intensive care unit, and eight (3.6%) required mechanical ventilation.

Conclusion

Of the pediatric patients with pandemic influenza A (H1N1) 2009, most of the patients were in the 5- to 9-year-old age group. Risk factors for hospitalization included male gender, <2 years of age, and underlying disease. The most common complication was pneumonia. The very high risk of severe morbidity in children with asthma or neurologic disease shows the critical importance of targeted vaccine coverage, special awareness and swift care by both guardians and primary care providers.

Emotional and social effects of congenital heart disease in Singapore

A cohort of patients with congenital heart disease (n = 29) who had undergone corrective cardiac surgery was studied and compared with normal controls. The mean age of cardiac patients was 10.3 years with a range of 6 years to 16 years. Their emotional maladjustment as measured on a behavioural checklist was significantly higher (P less than 0.01) than controls, and their social adjustment was also similarly less satisfactory (P less than 0.05). Regression analysis indicated that emotional maladjustment in the child was related to maternal maladjustment (P less than 0.01), maternal guilt (P less than 0.01) and maternal anxiety (P less than 0.05). Social maladjustment in the child was significantly related to maternal guilt (P less than 0.05) and pampering (P less than 0.02). It was considered that the child with heart disease was perceived and 'labelled' by the mother as abnormal even after surgery and was therefore the object and focus of maternal guilt and anxiety. Hence, the child's emotional and social maladjustment is probably the result of maternal factors rather than the physical handicaps of the illness.